Insects of Britain and Ireland: the families of Coleoptera

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L. Watson and M. J. Dallwitz

Conventional key

If you are serious about identification, you should use the interactive key. It is far superior, with flexible choice of characters, character notes and illustrations, error tolerance, full taxon descriptions, and taxon illustrations.

1(0).
  • Water beetles ... 2
  • Land dwellers... 17

2(1).
  • Antennae filiform ... 3
  • Antennae gradually expanding towards the apex ... Chrysomelidae
  • Antennae clubbed... 9
  • Antennae serrate... 16
  • Antennae pectinate ... Dryopidae

3(2).
  • Aquatic beetles ‘rowing’ by parallel-simultaneous leg movements ... 4
  • Aquatic beetles moving in the water by alternate, walking leg movements... 6

4(3).
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 5 ... 5
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 4, 4, 4 ... Chrysomelidae
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 4, 4, 5 ... Dytiscidae

5(4).
  • The apical segment of the labial palps more or less expanded apically; hind-leg coxae constituting longitudinal plates that are fused to one another and joined with the metasternum, endowing the beetle ventrally with a flat, median longitudinal keel; the antennae of the larva 0.15-0.5 x the head width; the mesothoracic legs of the larva with 1 movable claw ... Noteridae
  • The apical segment of the labial palps not expanded apically; hind-leg coxae not incorporated with the metasternum in a flat, median longitudinal keel; the antennae of the larva more than 0.5 x the width of the head; the mesothoracic legs of the larva with 2 movable claws ... Dytiscidae

6(3).
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 5; mid-leg tarsi with 5 segments, all conspicuous; the tarsi without ‘hidden’ segments; the larvae campodeiform ... 7
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 4, 4, 4; mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one; the tarsi with a tiny penultimate segment hidden by distal lobing of the fourth and fused to the fifth; the larvae scarabaeiform ... Chrysomelidae

7(6).
  • Scutellum conspicuous ... 8
  • Scutellum highly reduced ... Hygrobiidae
  • Scutellum absent ... Haliplidae

8(7).
  • The underside of the beetle exhibiting a plastron of hydrofuge hairs, detectable as a bubble when the insect is submerged; prothorax without notopleural sutures; beetles not noticeably posing regularly at the water surface to replenish air; scutellum elevated abruptly and fairly sharply above the mesoscutum in lateral view; mandibles with a well developed mola ... Elmidae
  • The underside of the beetle without a plastron of hydrofuge hairs; prothorax with notopleural sutures; beetles regularly posing tail first at the water surface to replenish air; scutellum not elevated; mandibles with a reduced mola ... Hygrobiidae

9(2).
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 5 ... 10
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 4, 4, 4... 13
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 3, 3, 3 ... Sphaeriidae

10(9).
  • Aquatic beetles ‘rowing’ by parallel-simultaneous leg movements; prothorax with notopleural sutures; the hind-leg coxae much enlarged; beetles surface swimmers with the main thrust delivered by the specialised middle legs, moving clumsily on land (Whirligigs); compound eyes ostensibly four ... Gyrinidae
  • Aquatic beetles moving in the water by alternate, walking leg movements; prothorax without notopleural sutures; the hind-leg coxae not much enlarged; beetles walking in water or free-swimming by conventional ambulatory motion of the legs, not diving strongly; compound eyes two, entire... 11

11(10).
  • Hind-leg coxae posteriorly shaped to receive the retracted femur ... Limnichidae
  • Hind-leg coxae not shaped posteriorly to receive the femur... 12

12(11).
  • The maxillary palps conspicuously elongated, often longer than the antennae; antennae not strongly asymmetric; hind-leg coxae without the steep transverse declivity characteristic of Dryopoidea; the claws of the mid-leg tarsi with an empodium between them; the larvae not C-shaped ... Hydrophilidae
  • The maxillary palps not especially elongated; antennae strongly asymmetric; hind-leg coxae with a steep transverse declivity against which the femur retracts; the claws of the mid-leg tarsi without an associated empodium; the larvae C-shaped in lateral view ... Dryopidae

13(9).
  • Abdominal sternites all articulated and moveable ... 14
  • Abdominal sternites comprising both fused and moveable components... 15

14(13).
  • The underside of the beetle exhibiting a plastron of hydrofuge hairs, detectable as a bubble when the insect is submerged; beetles regularly posing head first at the water surface to replenish air; beetles somewhat waisted; the claws of the mid-leg tarsi with an empodium between them; the male external genitalia trilobate ... Hydrophilidae
  • The underside of the beetle without a plastron of hydrofuge hairs; beetles not noticeably posing regularly at the water surface to replenish air; beetles conspicuously waisted; the claws of the mid-leg tarsi without an associated empodium; the male external genitalia staphylinoid ... Hydraenidae

15(13).
  • The underside of the beetle exhibiting a plastron of hydrofuge hairs, detectable as a bubble when the insect is submerged; beetles somewhat waisted; hind-leg coxae not shaped posteriorly to receive the femur; hind-leg coxae without the steep transverse declivity characteristic of Dryopoidea; the maxillary palps conspicuously elongated, often longer than the antennae ... Hydrophilidae
  • The underside of the beetle without a plastron of hydrofuge hairs; beetles conspicuously waisted; hind-leg coxae posteriorly shaped to receive the retracted femur; hind-leg coxae with a steep transverse declivity against which the femur retracts; the maxillary palps not especially elongated ... Heteroceridae

16(2).
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 5; mid-leg tarsi with 5 segments, all conspicuous; metaventrite with a transverse groove; hind-leg coxae posteriorly shaped to receive the retracted femur; hind-leg coxae with a steep transverse declivity against which the femur retracts ... Psephenidae
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 4, 4, 4; mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one; metaventrite without a transverse groove; hind-leg coxae not shaped posteriorly to receive the femur; hind-leg coxae without the steep transverse declivity characteristic of Dryopoidea ... Chrysomelidae

17(1).
  • Beetles equipped with a rostrum ... 18
  • Beetles without a rostrum... 24

18(17).
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 4; the fore-leg coxal cavities open behind externally; the last abdominal segment of the larva with cerci ... 19
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 4, 4, 4; the fore-leg coxal cavities closed behind externally; the last abdominal segment of the larva without cerci... 20

19(18).
  • Body noticeably widest immediately behind the thorax; cervical sclerites absent; body somewhat flattened ... Salpingidae
  • Body not noticeably widest either behind the thorax, or at the rear; cervical sclerites present; body strongly flattened ... Mycteridae

20(18).
  • Antennae filiform ... Anthribidae
  • Antennae gradually expanding towards the apex ... Nemonychidae
  • Antennae clubbed... 21

21(20).
  • The maxillae with distinct galea and lacinia apically to the palp ... 22
  • The maxillae with a single apical structure additional to the palp... 23

22(21).
  • Beetles conspicuously necked; the labrum concealed beneath the clypeus; the maxillary palps if visible, short and rigid; the penultimate segment distinctly shorter than the antepenultimate one; the male external genitalia cucujiform ... Attelabidae
  • Beetles not necked; the labrum at least partly visible in antero-dorsal view; the maxillary palps normal, flexible; the penultimate segment not shorter than the antepenultimate one; the male external genitalia chrysomeloid ... Anthribidae

23(21).
  • Beetles somewhat waisted; antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); antennae not elbowed; the male external genitalia cucujiform ... Apionidae
  • Beetles conspicuously waisted; antennae with the first segment (scape) much-elongated; antennae conspicuously elbowed; the male external genitalia curculionoid ... Curculionidae

24(17).
  • The fore-leg coxae countersunk in ‘procoxal cavities’ ... 25
  • The fore-leg coxae attached externally, in the absence of procoxal cavities... 271

25(24).
  • Elytra covering most to all of the abdomen ... 26
  • Elytra short, exposing several terminal abdominal tergites... 242
  • Elytra greatly reduced ... Oedemeridae

26(25).
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 0, 5, 5 ... Scarabaeidae
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 5... 27
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 4... 124
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 4, 4, 4... 167
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 4, 4, 3 ... Aderidae
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 3, 3, 3... 233
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 4, 4 ... Colydiidae
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 3, 3 ... Leiodidae
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 4, 3, 3 ... Leiodidae
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 0-2, 3, 3 ... Ptiliidae

27(26).
  • Antennae filiform ... 28
  • Antennae gradually expanding towards the apex... 51
  • Antennae clubbed... 54
  • Antennae serrate... 113
  • Antennae pectinate... 120

28(27).
  • Abdominal sternites all articulated and moveable ... 29
  • Abdominal sternites comprising both fused and moveable components... 37
  • Abdominal sternites all fused and immoveable... 50

29(28).
  • Hind-leg coxae posteriorly shaped to receive the retracted femur ... 30
  • Hind-leg coxae not shaped posteriorly to receive the femur... 32

30(29).
  • Antennal scape swollen; hindwings with an anal lobe; abdominal segment 8 apparently without functional spiracles; larvae aquatic; the larvae dorsally heavily pigmented or sclerotized ... Scirtidae
  • Antennal scape not swollen; hindwings without an anal lobe; abdominal segment 8 with apparently functional spiracles; larvae non-aquatic; the larvae dorsally only very lightly pigmented or sclerotized... 31

31(30).
  • The fore-leg coxal cavities narrowly separated; the mid-leg coxal cavities narrowly separated; beetles somewhat waisted; the male external genitalia trilobate; frontoclypeal suture of the larva between frons and clypeus indistinct or absent ... Dascillidae
  • The fore-leg coxal cavities quite widely separated; the mid-leg coxal cavities moderately to widely separated; beetles conspicuously waisted; the male external genitalia buprestoid; frontoclypeal suture of the larva between frons and clypeus distinct ... Buprestidae

32(29).
  • The head covered by the thorax; elytra not meeting along the full length of the mid-line ... Lampyridae (males)
  • The head not covered by the thorax; elytra meeting along the length of the mid-line... 33

33(32).
  • The mid-leg cavities open laterally ... 34
  • The mid-leg cavities closed laterally... 36

34(33).
  • Abdominal sternites 5 ... Cucujidae
  • Abdominal sternites 6 to 7... 35

35(34).
  • Hind-leg coxae contiguous or narrowly separated; the male external genitalia cucujiform; the labrum and head capsule of the larva separated by a complete suture; apices of the mandibles of the larva bilobed or bidentate; tergum 9 of the abdomen of the larva extending to the underside ... Melyridae
  • Hind-leg coxae widely separated; the male external genitalia staphylinoid; the labrum and head capsule of the larva completely fused, with no suture apparent; apices of the mandibles of the larva with a single lobe or tooth; tergum 9 of the abdomen of the larva entirely dorsal ... Scydmaenidae

36(33).
  • Beetles conspicuously necked; the mesocoxae separated by less than the shortest diameter of the cavity; elytra not truncate; adults predacious; larvae predacious ... Scydmaenidae
  • Beetles not necked; the mesocoxae separated by more than the shortest diameter of the cavity; elytra truncate; adults not predacious; larvae not predacious ... Scaphidiidae

37(28).
  • Prothorax with notopleural sutures; hind-leg coxae immoveably fixed to the metasternum and dividing the first abdominal sternite ... 38
  • Prothorax without notopleural sutures; hind-leg coxae moveable... 39

38(37).
  • Elytra striate; the last abdominal segment of the larva with cerci ... Carabidae
  • Elytra without striae; the last abdominal segment of the larva without cerci ... Cicindelidae

39(37).
  • The hind-leg coxae much enlarged ... Eucinetidae
  • The hind-leg coxae not much enlarged... 40

40(39).
  • The mid-leg cavities open laterally ... 41
  • The mid-leg cavities closed laterally... 48

41(40).
  • Hind-leg coxae extending laterally to meet the elytra ... 42
  • Hind-leg coxae not markedly extended laterally... 47

42(41).
  • Beetles not waisted ... Elateridae
  • Beetles somewhat waisted... 43
  • Beetles conspicuously waisted... 46

43(42).
  • Scutellum elevated abruptly and fairly sharply above the mesoscutum in lateral view ... 44
  • Scutellum not elevated... 45

44(43).
  • Antennal scape swollen; hindwings with an anal lobe; abdominal segment 8 apparently without functional spiracles; larvae aquatic; the larvae dorsally heavily pigmented or sclerotized ... Scirtidae
  • Antennal scape not swollen; hindwings without an anal lobe; abdominal segment 8 with apparently functional spiracles; larvae non-aquatic; the larvae dorsally only very lightly pigmented or sclerotized ... Dascillidae

45(43).
  • Hind-leg coxae posteriorly shaped to receive the retracted femur; abdominal sternites 5; larvae aquatic; the larvae dorsally heavily pigmented or sclerotized; apices of the mandibles of the larva with a single lobe or tooth ... Scirtidae
  • Hind-leg coxae not shaped posteriorly to receive the femur; abdominal sternites 6 to 7; larvae non-aquatic; the larvae dorsally only very lightly pigmented or sclerotized; apices of the mandibles of the larva bilobed or bidentate ... Melyridae

46(42).
  • Metaventrite with a transverse groove; hind-leg coxae posteriorly shaped to receive the retracted femur; elytra hard; elytra striate; abdominal segment 8 with apparently functional spiracles ... Buprestidae
  • Metaventrite without a transverse groove; hind-leg coxae not shaped posteriorly to receive the femur; elytra soft; elytra without striae; abdominal segment 8 apparently without functional spiracles ... Melyridae

47(41).
  • Antennal insertions visible from above; cervical sclerites present; compound eyes present; abdominal segment 8 apparently without functional spiracles; the male external genitalia cucujiform ... Melyridae
  • Antennal insertions hidden from above; cervical sclerites absent; compound eyes absent; abdominal segment 8 with apparently functional spiracles; the male external genitalia staphylinoid ... Leptinidae

48(40).
  • Hind-leg coxae posteriorly shaped to receive the retracted femur ... 49
  • Hind-leg coxae not shaped posteriorly to receive the femur ... Ptinidae

49(48).
  • Beetles clicking and ‘jumping’ to right themselves when inverted; the head not covered by the thorax; cervical sclerites present; the claws of the mid-leg tarsi with an empodium between them; the male external genitalia trilobate ... Elateridae
  • Beetles not clicking and ‘jumping’; the head covered by the thorax; cervical sclerites absent; the claws of the mid-leg tarsi without an associated empodium; the male external genitalia bostrichoid ... Anobiidae

50(28).
  • The mid-leg cavities open laterally; the head not covered by the thorax; the labrum concealed beneath the clypeus; cervical sclerites present; the male external genitalia trilobate ... Eucnemidae
  • The mid-leg cavities closed laterally; the head covered by the thorax; the labrum at least partly visible in antero-dorsal view; cervical sclerites absent; the male external genitalia bostrichoid ... Anobiidae

51(27).
  • Abdominal sternites all articulated and moveable ... 52
  • Abdominal sternites comprising both fused and moveable components... 53

52(51).
  • The tarsi exhibiting bilobed segments; antennae not strongly asymmetric; prothorax longer than wide; prothorax at its widest markedly narrower than the adjoining part of the abdomen; elytra not truncate ... Cleridae
  • The tarsi without bilobed segments; antennae strongly asymmetric; prothorax shorter than wide; prothorax at its widest not markedly narrower than the adjoining part of the abdomen; elytra truncate ... Silphidae

53(51).
  • Hind-leg coxae extending laterally to meet the elytra; cervical sclerites present; the fore-leg coxal cavities strongly transverse; hind-leg coxae posteriorly shaped to receive the retracted femur; the tarsi without bilobed segments ... Byrrhidae
  • Hind-leg coxae not markedly extended laterally; cervical sclerites absent; the fore-leg coxal cavities circular to longer than wide; hind-leg coxae not shaped posteriorly to receive the femur; the tarsi exhibiting bilobed segments ... Leptinidae

54(27).
  • Abdominal sternites all articulated and moveable ... 55
  • Abdominal sternites comprising both fused and moveable components... 98
  • Abdominal sternites all fused and immoveable... 110

55(54).
  • Hind-leg coxae extending laterally to meet the elytra ... 56
  • Hind-leg coxae not markedly extended laterally... 74

56(55).
  • Mid-leg tarsi with 5 segments, all conspicuous ... 57
  • Mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one... 71
  • Mid-leg tarsi with 4 segments, all easily seen... 72
  • Mid-leg tarsi with 3 obvious segments plus a reduced penultimate one ... Lyctidae

57(56).
  • Antennae strongly asymmetric ... 58
  • Antennae not strongly asymmetric... 61

58(57).
  • The mid-leg cavities open laterally ... 59
  • The mid-leg cavities closed laterally ... Trogidae

59(58).
  • Compound eyes two, entire; frontoclypeal suture of the larva between frons and clypeus distinct ... 60
  • Compound eyes ostensibly four; frontoclypeal suture of the larva between frons and clypeus indistinct or absent ... Geotrupidae

60(59).
  • Antennae conspicuously elbowed; antennae with the first segment (scape) much-elongated ... Lucanidae
  • Antennae not elbowed; antennae without a much-elongated scape (though it is often longer than the adjoining, second segment) ... Scarabaeidae

61(57).
  • Cervical sclerites present ... 62
  • Cervical sclerites absent... 68

62(61).
  • Hind-leg coxae posteriorly shaped to receive the retracted femur ... Buprestidae
  • Hind-leg coxae not shaped posteriorly to receive the femur... 63

63(62).
  • Beetles not waisted ... Dermestidae
  • Beetles somewhat waisted... 64
  • Beetles conspicuously waisted... 65

64(63).
  • The maxillary palps conspicuously elongated, often longer than the antennae; the male external genitalia trilobate; the labrum and head capsule of the larva completely fused, with no suture apparent; the larvae with abdominal gills ... Hydrophilidae
  • The maxillary palps not especially elongated; the male external genitalia bostrichoid; the labrum and head capsule of the larva separated by a complete suture; the larvae without abdominal gills ... Dermestidae

65(63).
  • Beetles terrapin-like in shape, with flattened and clear margins to thorax and elytra ... Peltidae
  • Beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra... 66

66(65).
  • The tarsi exhibiting bilobed segments ... Cleridae
  • The tarsi without bilobed segments... 67

67(66).
  • Hind-leg coxae contiguous or narrowly separated; hindwings with an anal lobe; abdominal sternites 5; the mandibular apices bidentate or bilobed; the male external genitalia cucujiform ... Phloiophilidae
  • Hind-leg coxae widely separated; hindwings without an anal lobe; abdominal sternites 6 to 7; the mandibular apices simple; the male external genitalia staphylinoid ... Scydmaenidae

68(61).
  • The labrum at least partly visible in antero-dorsal view; antennae not elbowed; antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); the penultimate segment not shorter than the antepenultimate one; mesothoracic legs of the larva present and segmented ... 69
  • The labrum concealed beneath the clypeus; antennae conspicuously elbowed; antennae with the first segment (scape) much-elongated; the penultimate segment distinctly shorter than the antepenultimate one; mesothoracic legs of the larva much reduced or absent ... Platypodidae

69(68).
  • The head covered by the thorax; prothorax hooded and concealing the head, its front covered with large bumps ... Bostrychidae
  • The head not covered by the thorax; prothorax not hooded with anterior bumps... 70

70(69).
  • Beetles conspicuously necked; the fore-leg coxal cavities open behind externally; the fore-leg coxal cavities broadly open; scutellary striole absent; hindwings without an anal lobe ... Scydmaenidae
  • Beetles not necked; the fore-leg coxal cavities closed behind externally; the fore-leg coxal cavities broadly closed; scutellary striole present; hindwings with an anal lobe ... Lyctidae

71(56).
  • Beetles somewhat waisted; mandibles with a well developed mola; the maxillary palps conspicuously elongated, often longer than the antennae; prothorax shorter than wide; prothorax at its widest not markedly narrower than the adjoining part of the abdomen ... Hydrophilidae
  • Beetles conspicuously waisted; mandibles without a mola; the maxillary palps not especially elongated; prothorax longer than wide; prothorax at its widest markedly narrower than the adjoining part of the abdomen ... Cleridae

72(56).
  • Beetles not waisted ... Clambidae
  • Beetles somewhat waisted ... Hydrophilidae
  • Beetles conspicuously waisted... 73

73(72).
  • Mandibles with a well developed mola; beetles terrapin-like in shape, with flattened and clear margins to thorax and elytra; adults not predacious; larvae not predacious; apices of the mandibles of the larva bilobed or bidentate ... Peltidae
  • Mandibles without a mola; beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra; adults predacious; larvae predacious; apices of the mandibles of the larva with a single lobe or tooth ... Cleridae

74(55).
  • Hind-leg coxae posteriorly shaped to receive the retracted femur ... Nosodendridae
  • Hind-leg coxae not shaped posteriorly to receive the femur... 75

75(74).
  • The apical segment of the labial palps more or less expanded apically ... 76
  • The apical segment of the labial palps not expanded apically... 80

76(75).
  • The mid-leg cavities open laterally ... 77
  • The mid-leg cavities closed laterally... 78

77(76).
  • Mandibles with a well developed mola; prothorax shorter than wide; prothorax at its widest not markedly narrower than the adjoining part of the abdomen; the tarsi without bilobed segments; scutellary striole present ... Biphyllidae
  • Mandibles without a mola; prothorax longer than wide; prothorax at its widest markedly narrower than the adjoining part of the abdomen; the tarsi exhibiting bilobed segments; scutellary striole absent ... Cleridae

78(76).
  • Mandibles with a well developed mola; prothorax shorter than wide; prothorax at its widest not markedly narrower than the adjoining part of the abdomen; adults not predacious; larvae not predacious ... 79
  • Mandibles without a mola; prothorax longer than wide; prothorax at its widest markedly narrower than the adjoining part of the abdomen; adults predacious; larvae predacious ... Cleridae

79(78).
  • Beetles prognathous; greatest prothoracic width not narrower or only slightly narrower than the greatest elytral width; vestiture of the larva restricted to fine hairs or setae ... Erotylidae
  • Beetles not prognathous; greatest prothoracic width distinctly narrower than greatest elytral width; vestiture of the larva not restricted to fine hairs or setae ... Languriidae

80(75).
  • Metaventrite with a transverse groove ... 81
  • Metaventrite without a transverse groove... 82

81(80).
  • Beetles somewhat waisted; mandibles with a well developed mola; the maxillary palps conspicuously elongated, often longer than the antennae; antennal clubs 4 to 9 segmented; compound eyes not strongly protuberant ... Hydrophilidae
  • Beetles conspicuously waisted; mandibles with a reduced mola; the maxillary palps not especially elongated; antennal clubs up to 3 segmented; compound eyes strongly protuberant ... Sphaeritidae

82(80).
  • The head covered by the thorax; prothorax hooded and concealing the head, its front covered with large bumps ... Bostrychidae
  • The head not covered by the thorax; prothorax not hooded with anterior bumps... 83

83(82).
  • Antennae conspicuously elbowed; antennae with the first segment (scape) much-elongated ... Histeridae
  • Antennae not elbowed; antennae without a much-elongated scape (though it is often longer than the adjoining, second segment)... 84

84(83).
  • The tarsi exhibiting bilobed segments ... 85
  • The tarsi without bilobed segments... 87

85(84).
  • Mandibles with a well developed mola; prothorax shorter than wide; prothorax at its widest not markedly narrower than the adjoining part of the abdomen; adults not predacious; larvae not predacious ... 86
  • Mandibles without a mola; prothorax longer than wide; prothorax at its widest markedly narrower than the adjoining part of the abdomen; adults predacious; larvae predacious ... Cleridae

86(85).
  • The fore-leg coxal cavities open behind externally; elytral epipleura falling short of the elytral tips ... Cryptophagidae
  • The fore-leg coxal cavities closed behind externally; elytral epipleura reaching to the tips of the elytra ... Erotylidae

87(84).
  • Antennae 1 to 4 segmented ... Leiodidae
  • Antennae 5 to 8 segmented ... Hydrophilidae
  • Antennae 9 to 10 segmented... 88
  • Antennae 11 segmented... 92

88(87).
  • Beetles not waisted ... 89
  • Beetles somewhat waisted... 90
  • Beetles conspicuously waisted ... Rhizophagidae

89(88).
  • Antennal segment 8 smaller than segments 7 and 9 ... Leiodidae
  • Antennal segment 8 not smaller than 7 and 9 ... Dermestidae

90(88).
  • Antennal segment 8 smaller than segments 7 and 9 ... Leiodidae
  • Antennal segment 8 not smaller than 7 and 9... 91

91(90).
  • The maxillary palps conspicuously elongated, often longer than the antennae; the male external genitalia trilobate; the labrum and head capsule of the larva completely fused, with no suture apparent; the larvae with abdominal gills ... Hydrophilidae
  • The maxillary palps not especially elongated; the male external genitalia bostrichoid; the labrum and head capsule of the larva separated by a complete suture; the larvae without abdominal gills ... Dermestidae

92(87).
  • Beetles conspicuously necked; the labrum and head capsule of the larva completely fused, with no suture apparent ... Scydmaenidae
  • Beetles not necked; the labrum and head capsule of the larva separated by a complete suture... 93

93(92).
  • Antennae strongly asymmetric ... Silphidae
  • Antennae not strongly asymmetric... 94

94(93).
  • Scutellary striole present; the larvae C-shaped in lateral view ... Lyctidae
  • Scutellary striole absent; the larvae not C-shaped... 95

95(94).
  • Antennal segment 8 smaller than segments 7 and 9 ... Leiodidae
  • Antennal segment 8 not smaller than 7 and 9... 96

96(95).
  • Abdominal sternites 5 ... 97
  • Abdominal sternites 6 to 7 ... Scaphidiidae

97(96).
  • Abdominal segment 8 with apparently functional spiracles; the male external genitalia bostrichoid ... Dermestidae
  • Abdominal segment 8 apparently without functional spiracles; the male external genitalia cucujiform ... Cucujidae

98(54).
  • Hind-leg coxae posteriorly shaped to receive the retracted femur ... 99
  • Hind-leg coxae not shaped posteriorly to receive the femur... 102

99(98).
  • The mid-leg cavities open laterally; the head not covered by the thorax; cervical sclerites present; the fore-leg coxal cavities internally open; the larvae not C-shaped ... 100
  • The mid-leg cavities closed laterally; the head covered by the thorax; cervical sclerites absent; the fore-leg coxal cavities internally closed by a slender bar; the larvae C-shaped in lateral view ... Anobiidae

100(99).
  • The apical segment of the labial palps more or less expanded apically; hindwings with an anal lobe; the apical segment of the maxillary palps somewhat expanded and truncate to subtriangular; frontoclypeal suture of the larva between frons and clypeus indistinct or absent; the labrum and head capsule of the larva completely fused, with no suture apparent ... Throscidae
  • The apical segment of the labial palps not expanded apically; hindwings without an anal lobe; the apical segment of the maxillary palps cylindrical to fusiform; frontoclypeal suture of the larva between frons and clypeus distinct; the labrum and head capsule of the larva separated by a complete suture... 101

101(100).
  • Mandibles with a well developed mola; mandibles with well developed prosthecae; hind-leg coxae with a steep transverse declivity against which the femur retracts; the tarsi without bilobed segments; beetles not waisted ... Limnichidae
  • Mandibles without a mola; mandibles without prosthecae; hind-leg coxae without the steep transverse declivity characteristic of Dryopoidea; the tarsi exhibiting bilobed segments; beetles conspicuously waisted ... Buprestidae

102(98).
  • Antennae strongly asymmetric ... 103
  • Antennae not strongly asymmetric... 104

103(102).
  • Hind-leg coxae extending laterally to meet the elytra; antennae conspicuously elbowed; antennae with the first segment (scape) much-elongated; the fore-leg coxal cavities closed behind externally; hind-leg coxae without the steep transverse declivity characteristic of Dryopoidea ... Lucanidae
  • Hind-leg coxae not markedly extended laterally; antennae not elbowed; antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); the fore-leg coxal cavities open behind externally; hind-leg coxae with a steep transverse declivity against which the femur retracts ... Dryopidae

104(102).
  • Cervical sclerites present ... 105
  • Cervical sclerites absent... 109

105(104).
  • Beetles terrapin-like in shape, with flattened and clear margins to thorax and elytra ... Peltidae
  • Beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra... 106

106(105).
  • The tarsi exhibiting bilobed segments ... Erotylidae
  • The tarsi without bilobed segments... 107

107(106).
  • The maxillary palps conspicuously elongated, often longer than the antennae; the labrum and head capsule of the larva completely fused, with no suture apparent; the larvae with abdominal gills ... Hydrophilidae
  • The maxillary palps not especially elongated; the labrum and head capsule of the larva separated by a complete suture; the larvae without abdominal gills... 108

108(107).
  • Antennal segment 8 smaller than segments 7 and 9 ... Leiodidae
  • Antennal segment 8 not smaller than 7 and 9 ... Dermestidae

109(104).
  • The mid-leg cavities open laterally; antennal clubs 4 to 9 segmented; antennal segment 8 smaller than segments 7 and 9; the fore-leg coxal cavities open behind externally; hindwings without an anal lobe ... Leiodidae
  • The mid-leg cavities closed laterally; antennal clubs up to 3 segmented; antennal segment 8 not smaller than 7 and 9; the fore-leg coxal cavities closed behind externally; hindwings with an anal lobe ... Lyctidae

110(54).
  • The mid-leg cavities open laterally; the head not covered by the thorax; cervical sclerites present ... 111
  • The mid-leg cavities closed laterally; the head covered by the thorax; cervical sclerites absent ... Anobiidae

111(110).
  • Antennae strongly asymmetric; the fore-leg coxal cavities closed behind externally; antennal clubs lamellate ... Scarabaeidae
  • Antennae not strongly asymmetric; the fore-leg coxal cavities open behind externally; antennal clubs not lamellate... 112

112(111).
  • Beetles dorsally flattened; beetles conspicuously waisted; the mesocoxae separated by less than the shortest diameter of the cavity; beetles terrapin-like in shape, with flattened and clear margins to thorax and elytra; hind-leg coxae not shaped posteriorly to receive the femur ... Peltidae
  • Beetles dorsally strongly convex; beetles not waisted; the mesocoxae separated by more than the shortest diameter of the cavity; beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra; hind-leg coxae posteriorly shaped to receive the retracted femur ... Limnichidae

113(27).
  • Abdominal sternites all articulated and moveable ... 114
  • Abdominal sternites comprising both fused and moveable components... 115
  • Abdominal sternites all fused and immoveable... 119

114(113).
  • Metaventrite with a transverse groove; hind-leg coxae posteriorly shaped to receive the retracted femur; elytra hard; elytra striate; abdominal segment 8 with apparently functional spiracles ... Buprestidae
  • Metaventrite without a transverse groove; hind-leg coxae not shaped posteriorly to receive the femur; elytra soft; elytra without striae; abdominal segment 8 apparently without functional spiracles ... Melyridae

115(113).
  • The labrum at least partly visible in antero-dorsal view; hind-leg coxae without the steep transverse declivity characteristic of Dryopoidea; larvae non-aquatic; the larvae neither strongly flattened nor disc-like; vestiture of the larva restricted to fine hairs or setae ... 116
  • The labrum concealed beneath the clypeus; hind-leg coxae with a steep transverse declivity against which the femur retracts; larvae aquatic; the larvae strongly flattened and disc-like; vestiture of the larva not restricted to fine hairs or setae ... Psephenidae

116(115).
  • Beetles clicking and ‘jumping’ to right themselves when inverted; the labrum and head capsule of the larva completely fused, with no suture apparent ... Elateridae
  • Beetles not clicking and ‘jumping’; the labrum and head capsule of the larva separated by a complete suture... 117

117(116).
  • The mid-leg cavities open laterally; the head not covered by the thorax; cervical sclerites present; the fore-leg coxal cavities internally open; the larvae not C-shaped ... 118
  • The mid-leg cavities closed laterally; the head covered by the thorax; cervical sclerites absent; the fore-leg coxal cavities internally closed by a slender bar; the larvae C-shaped in lateral view ... Anobiidae

118(117).
  • Metaventrite with a transverse groove; hind-leg coxae posteriorly shaped to receive the retracted femur; elytra hard; elytra striate; abdominal segment 8 with apparently functional spiracles ... Buprestidae
  • Metaventrite without a transverse groove; hind-leg coxae not shaped posteriorly to receive the femur; elytra soft; elytra without striae; abdominal segment 8 apparently without functional spiracles ... Melyridae

119(113).
  • The mid-leg cavities open laterally; the head not covered by the thorax; the labrum concealed beneath the clypeus; cervical sclerites present; the male external genitalia trilobate ... Eucnemidae
  • The mid-leg cavities closed laterally; the head covered by the thorax; the labrum at least partly visible in antero-dorsal view; cervical sclerites absent; the male external genitalia bostrichoid ... Anobiidae

120(27).
  • Abdominal sternites all articulated and moveable ... Drilidae (males)
  • Abdominal sternites comprising both fused and moveable components... 121
  • Abdominal sternites all fused and immoveable... 123

121(120).
  • The claws of the mid-leg tarsi with an empodium between them; beetles clicking and ‘jumping’ to right themselves when inverted; the larvae not C-shaped; frontoclypeal suture of the larva between frons and clypeus indistinct or absent; the labrum and head capsule of the larva completely fused, with no suture apparent ... Elateridae
  • The claws of the mid-leg tarsi without an associated empodium; beetles not clicking and ‘jumping’; the larvae C-shaped in lateral view; frontoclypeal suture of the larva between frons and clypeus distinct; the labrum and head capsule of the larva separated by a complete suture... 122

122(121).
  • The mid-leg cavities open laterally; the head not covered by the thorax; mandibles with a well developed mola; antennae strongly asymmetric; cervical sclerites present ... Dryopidae
  • The mid-leg cavities closed laterally; the head covered by the thorax; mandibles without a mola; antennae not strongly asymmetric; cervical sclerites absent ... Anobiidae

123(120).
  • The mid-leg cavities open laterally; the head not covered by the thorax; the labrum concealed beneath the clypeus; cervical sclerites present; the male external genitalia trilobate ... Eucnemidae
  • The mid-leg cavities closed laterally; the head covered by the thorax; the labrum at least partly visible in antero-dorsal view; cervical sclerites absent; the male external genitalia bostrichoid ... Anobiidae

124(26).
  • Antennae filiform ... 125
  • Antennae gradually expanding towards the apex... 140
  • Antennae clubbed... 145
  • Antennae serrate ... Pyrochroidae
  • Antennae pectinate ... Pyrochroidae
  • Antennae plumose or biplumose ... Pyrochroidae

125(124).
  • Abdominal sternites all articulated and moveable ... 126
  • Abdominal sternites comprising both fused and moveable components... 134
  • Abdominal sternites all fused and immoveable ... Anthicidae

126(125).
  • Elytra exposing no more than part of the terminal tergite ... 127
  • Elytra exposing at least one but fewer than three complete abdominal tergites... 131
  • Elytra exposing at least three complete abdominal tergites... 133

127(126).
  • The mid-leg cavities open laterally ... 128
  • The mid-leg cavities closed laterally ... Salpingidae

128(127).
  • Beetles conspicuously necked ... 129
  • Beetles not necked... 130

129(128).
  • The tarsi exhibiting bilobed segments; elytra meeting along the length of the mid-line; the pronotum with lateral keels (pronotal carinae); larvae not predacious ... Scraptiidae
  • The tarsi without bilobed segments; elytra not meeting along the full length of the mid-line; the pronotum without lateral keels; larvae predacious ... Meloïdae

130(128).
  • Beetles prognathous; elytra not individually tapered; elytra glabrous; the male external genitalia cucujiform ... Cucujidae
  • Beetles not prognathous; elytra individually distinctly tapered to their apices; elytra non-glabrous; the male external genitalia tenebrionoid ... Melandryidae

131(126).
  • The hind-leg coxae much enlarged; antennal insertions hidden from above; the fore-leg coxal cavities narrowly separated; the mesocoxae separated by more than the shortest diameter of the cavity; the end of the abdomen extended as a long, narrow point beyond the ends of the truncate elytra ... Mordellidae
  • The hind-leg coxae not much enlarged; antennal insertions visible from above; the fore-leg coxal cavities medianly confluent; the mesocoxae separated by less than the shortest diameter of the cavity; the end of the abdomen not extended as a long, narrow point beyond the ends of the elytra... 132

132(131).
  • The pronotum with lateral keels (pronotal carinae); the tarsi exhibiting bilobed segments; elytra meeting along the length of the mid-line; larvae not predacious ... Scraptiidae
  • The pronotum without lateral keels; the tarsi without bilobed segments; elytra not meeting along the full length of the mid-line; larvae predacious ... Meloïdae

133(126).
  • The mid-leg cavities open laterally; hind-leg coxae extending laterally to meet the elytra; beetles conspicuously necked; cervical sclerites present; elytra not meeting along the full length of the mid-line ... Meloïdae
  • The mid-leg cavities closed laterally; hind-leg coxae not markedly extended laterally; beetles not necked; cervical sclerites absent; elytra meeting along the length of the mid-line ... Salpingidae

134(125).
  • Elytra exposing no more than part of the terminal tergite ... 135
  • Elytra exposing at least one but fewer than three complete abdominal tergites... 139
  • Elytra exposing at least three complete abdominal tergites ... Salpingidae

135(134).
  • The mid-leg cavities open laterally ... 136
  • The mid-leg cavities closed laterally... 138

136(135).
  • Elytra individually distinctly tapered to their apices; antennal insertions not hidden by lateral extensions of the frons ... Melandryidae
  • Elytra not individually tapered; antennal insertions hidden by lateral extensions of the frons... 137

137(136).
  • Cervical sclerites present; frontoclypeal suture of the larva between frons and clypeus indistinct or absent ... Pythidae
  • Cervical sclerites absent; frontoclypeal suture of the larva between frons and clypeus distinct ... Tenebrionidae

138(135).
  • Basal abdominal sternites immovably joined 2; elytra glossy; frontoclypeal suture of the larva between frons and clypeus indistinct or absent ... Salpingidae
  • Basal abdominal sternites immovably joined 3 to 4; elytra dull; frontoclypeal suture of the larva between frons and clypeus distinct ... Tenebrionidae

139(134).
  • Cervical sclerites present; prothorax longer than wide; the tarsi exhibiting bilobed segments; elytra not meeting along the full length of the mid-line; basal abdominal sternites immovably joined 2 ... Oedemeridae
  • Cervical sclerites absent; prothorax shorter than wide; the tarsi without bilobed segments; elytra meeting along the length of the mid-line; basal abdominal sternites immovably joined 3 to 4 ... Tenebrionidae

140(124).
  • Abdominal sternites all articulated and moveable ... 141
  • Abdominal sternites comprising both fused and moveable components... 143
  • Abdominal sternites all fused and immoveable ... Anthicidae

141(140).
  • Elytra exposing no more than part of the terminal tergite ... 142
  • Elytra exposing at least one but fewer than three complete abdominal tergites ... Mordellidae
  • Elytra exposing at least three complete abdominal tergites ... Salpingidae

142(141).
  • The mid-leg cavities open laterally; beetles not prognathous; elytra individually distinctly tapered to their apices ... Melandryidae
  • The mid-leg cavities closed laterally; beetles prognathous; elytra not individually tapered ... Salpingidae

143(140).
  • Basal abdominal sternites immovably joined 2 ... 144
  • Basal abdominal sternites immovably joined 3 to 4 ... Tenebrionidae

144(143).
  • The mid-leg cavities open laterally; beetles not prognathous; elytra individually distinctly tapered to their apices ... Melandryidae
  • The mid-leg cavities closed laterally; beetles prognathous; elytra not individually tapered ... Salpingidae

145(124).
  • Elytra exposing no more than part of the terminal tergite ... 146
  • Elytra exposing at least one but fewer than three complete abdominal tergites... 160
  • Elytra exposing at least three complete abdominal tergites... 164

146(145).
  • Abdominal sternites all articulated and moveable ... 147
  • Abdominal sternites comprising both fused and moveable components... 156

147(146).
  • The tarsi exhibiting bilobed segments ... 148
  • The tarsi without bilobed segments... 149

148(147).
  • Scutellum elevated abruptly and fairly sharply above the mesoscutum in lateral view; the mid-leg cavities closed laterally; beetles prognathous; the fore-leg coxal cavities quite widely separated; the claws of the mid-leg tarsi simple ... Cryptophagidae
  • Scutellum not elevated; the mid-leg cavities open laterally; beetles not prognathous; the fore-leg coxal cavities narrowly separated; the claws of the mid-leg tarsi one-toothed or bifid ... Byturidae

149(147).
  • Beetles exhibiting bright ‘warning colours’ ... Tetratomidae
  • Beetles without ‘warning colouration’... 150

150(149).
  • Hind-leg coxae extending laterally to meet the elytra ... 151
  • Hind-leg coxae not markedly extended laterally... 152

151(150).
  • Abdominal segment 8 with apparently functional spiracles; the male external genitalia bostrichoid ... Dermestidae
  • Abdominal segment 8 apparently without functional spiracles; the male external genitalia cucujiform ... Trogossitidae

152(150).
  • Antennal segment 8 smaller than segments 7 and 9 ... Leiodidae
  • Antennal segment 8 not smaller than 7 and 9... 153

153(152).
  • Antennae 9 to 10 segmented ... 154
  • Antennae 11 segmented... 155

154(153).
  • Antennal insertions visible from above; the fore-leg coxal cavities open behind externally; elytra not truncate; the fore-leg coxal cavities broadly open; abdominal segment 8 with apparently functional spiracles ... Dermestidae
  • Antennal insertions hidden from above; the fore-leg coxal cavities closed behind externally; elytra truncate; the fore-leg coxal cavities broadly closed; abdominal segment 8 apparently without functional spiracles ... Rhizophagidae

155(153).
  • Abdominal segment 8 with apparently functional spiracles; the male external genitalia bostrichoid ... Dermestidae
  • Abdominal segment 8 apparently without functional spiracles; the male external genitalia cucujiform ... Cucujidae

156(146).
  • Beetles exhibiting bright ‘warning colours’ ... Tetratomidae
  • Beetles without ‘warning colouration’... 157

157(156).
  • Antennal segment 8 smaller than segments 7 and 9 ... Leiodidae
  • Antennal segment 8 not smaller than 7 and 9... 158

158(157).
  • Cervical sclerites present; hind tarsi with as many segments as the mid-tarsi ... 159
  • Cervical sclerites absent; hind tarsi with one segment fewer than the mid-tarsi ... Tenebrionidae

159(158).
  • Abdominal segment 8 with apparently functional spiracles; the male external genitalia bostrichoid ... Dermestidae
  • Abdominal segment 8 apparently without functional spiracles; the male external genitalia cucujiform ... Trogossitidae

160(145).
  • Abdominal sternites all articulated and moveable ... 161
  • Abdominal sternites comprising both fused and moveable components... 163

161(160).
  • The hind-leg coxae much enlarged; hind-leg coxae extending laterally to meet the elytra; the claws of the mid-leg tarsi serrate, denticulate or pectinate; the end of the abdomen extended as a long, narrow point beyond the ends of the truncate elytra; frontoclypeal suture of the larva between frons and clypeus distinct ... Mordellidae
  • The hind-leg coxae not much enlarged; hind-leg coxae not markedly extended laterally; the claws of the mid-leg tarsi simple; the end of the abdomen not extended as a long, narrow point beyond the ends of the elytra; frontoclypeal suture of the larva between frons and clypeus indistinct or absent... 162

162(161).
  • Antennal clubs up to 3 segmented; antennal segment 8 not smaller than 7 and 9; the fore-leg coxal cavities closed behind externally; tergum 9 of the abdomen of the larva extending to the underside ... Rhizophagidae
  • Antennal clubs 4 to 9 segmented; antennal segment 8 smaller than segments 7 and 9; the fore-leg coxal cavities open behind externally; tergum 9 of the abdomen of the larva entirely dorsal ... Leiodidae

163(160).
  • Basal abdominal sternites immovably joined 2; antennal segment 8 smaller than segments 7 and 9; frontoclypeal suture of the larva between frons and clypeus indistinct or absent ... Leiodidae
  • Basal abdominal sternites immovably joined 3 to 4; antennal segment 8 not smaller than 7 and 9; frontoclypeal suture of the larva between frons and clypeus distinct ... Tenebrionidae

164(145).
  • Hind-leg coxae extending laterally to meet the elytra ... 165
  • Hind-leg coxae not markedly extended laterally... 166

165(164).
  • Abdominal segment 8 with apparently functional spiracles; the male external genitalia bostrichoid ... Dermestidae
  • Abdominal segment 8 apparently without functional spiracles; the male external genitalia cucujiform ... Trogossitidae

166(164).
  • Antennal segment 8 smaller than segments 7 and 9 ... Leiodidae
  • Antennal segment 8 not smaller than 7 and 9 ... Dermestidae

167(26).
  • Antennae filiform ... 168
  • Antennae gradually expanding towards the apex... 176
  • Antennae clubbed... 189
  • Antennae serrate... 231
  • Antennae pectinate ... Ptilodactylidae

168(167).
  • Mid-leg tarsi with 5 segments, all conspicuous ... 169
  • Mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one... 171

169(168).
  • Beetles conspicuously necked; the prosternal process incomplete ... Scraptiidae
  • Beetles not necked; the prosternal process complete... 170

170(169).
  • Beetles prognathous; elytra not individually tapered; elytra glabrous; the male external genitalia cucujiform ... Cucujidae
  • Beetles not prognathous; elytra individually distinctly tapered to their apices; elytra non-glabrous; the male external genitalia tenebrionoid ... Melandryidae

171(168).
  • Abdominal sternites all articulated and moveable ... 172
  • Abdominal sternites comprising both fused and moveable components... 175

172(171).
  • The hind-leg coxae much enlarged; elytra truncate; labial palps of the larva absent or non-segmented ... Bruchidae
  • The hind-leg coxae not much enlarged; elytra not truncate; labial palps of the larva present and segmented... 173

173(172).
  • Compound eyes accommodating the antennae in an anterior notch ... Cerambycidae
  • Compound eyes not accommodating the antennae in a notch... 174

174(173).
  • Beetles conspicuously necked; hind tarsi with one segment fewer than the mid-tarsi; elytra non-glabrous ... Scraptiidae
  • Beetles not necked; hind tarsi with as many segments as the mid-tarsi; elytra glabrous ... Chrysomelidae

175(171).
  • Beetles conspicuously necked; hind tarsi with one segment fewer than the mid-tarsi; the last abdominal segment of the larva with cerci; larvae in decaying plant material; larvae consuming decaying plant material ... Aderidae
  • Beetles not necked; hind tarsi with as many segments as the mid-tarsi; the last abdominal segment of the larva without cerci; larvae on living vegetation; larvae phytophagous ... Chrysomelidae

176(167).
  • Abdominal sternites all articulated and moveable ... 177
  • Abdominal sternites comprising both fused and moveable components... 185

177(176).
  • Mid-leg tarsi with 5 segments, all conspicuous ... 178
  • Mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one... 180
  • Mid-leg tarsi with 4 segments, all easily seen... 183
  • Mid-leg tarsi with 3 obvious segments plus a reduced penultimate one ... Endomychidae
  • Mid-leg tarsi with 3 segments, all easily seen ... Mycetophagidae

178(177).
  • Elytra individually distinctly tapered to their apices; the male external genitalia tenebrionoid ... Melandryidae
  • Elytra not individually tapered; the male external genitalia cucujiform... 179

179(178).
  • Mandibles with a well developed mola; adults 1.5 to 5 mm long; adults not predacious; larvae not predacious; tergum 9 of the abdomen of the larva entirely dorsal ... Silvanidae
  • Mandibles without a mola; adults 5.1 to 20 mm long; adults predacious; larvae predacious; tergum 9 of the abdomen of the larva extending to the underside ... Cleridae

180(177).
  • Elytra non-glabrous ... 181
  • Elytra glabrous... 182

181(180).
  • Mandibles with a well developed mola; adults 1.5 to 5 mm long; adults not predacious; larvae not predacious; tergum 9 of the abdomen of the larva entirely dorsal ... Silvanidae
  • Mandibles without a mola; adults 5.1 to 20 mm long; adults predacious; larvae predacious; tergum 9 of the abdomen of the larva extending to the underside ... Cleridae

182(180).
  • Prothorax having the front corners produced, or with serrated sides ... Silvanidae
  • Prothorax with neither produced front corners nor serrated sides ... Chrysomelidae

183(177).
  • Prothorax shorter than wide; the tarsi without bilobed segments; the male external genitalia tenebrionoid ... Mycetophagidae
  • Prothorax longer than wide; the tarsi exhibiting bilobed segments; the male external genitalia cucujiform... 184

184(183).
  • Mandibles with a well developed mola; adults 1.5 to 5 mm long; adults not predacious; larvae not predacious; tergum 9 of the abdomen of the larva entirely dorsal ... Silvanidae
  • Mandibles without a mola; adults 5.1 to 20 mm long; adults predacious; larvae predacious; tergum 9 of the abdomen of the larva extending to the underside ... Cleridae

185(176).
  • Hind-leg coxae posteriorly shaped to receive the retracted femur ... Byrrhidae
  • Hind-leg coxae not shaped posteriorly to receive the femur... 186

186(185).
  • Mid-leg tarsi with 5 segments, all conspicuous ... 187
  • Mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one... 188
  • Mid-leg tarsi with 4 segments, all easily seen ... Silvanidae

187(186).
  • Beetles prognathous; hind tarsi with as many segments as the mid-tarsi; elytra not individually tapered; prothorax having the front corners produced, or with serrated sides; the male external genitalia cucujiform ... Silvanidae
  • Beetles not prognathous; hind tarsi with one segment fewer than the mid-tarsi; elytra individually distinctly tapered to their apices; prothorax with neither produced front corners nor serrated sides; the male external genitalia tenebrionoid ... Melandryidae

188(186).
  • Prothorax having the front corners produced, or with serrated sides ... Silvanidae
  • Prothorax with neither produced front corners nor serrated sides ... Chrysomelidae

189(167).
  • Abdominal sternites all articulated and moveable ... 190
  • Abdominal sternites comprising both fused and moveable components... 223
  • Abdominal sternites all fused and immoveable... 230

190(189).
  • The mid-leg cavities open laterally ... 191
  • The mid-leg cavities closed laterally... 215

191(190).
  • Mid-leg tarsi with 5 segments, all conspicuous ... 192
  • Mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one... 200
  • Mid-leg tarsi with 4 segments, all easily seen... 204
  • Mid-leg tarsi with 3 obvious segments plus a reduced penultimate one... 212
  • Mid-leg tarsi with 3 segments, all easily seen... 214

192(191).
  • Beetles not waisted ... 193
  • Beetles somewhat waisted... 194
  • Beetles conspicuously waisted... 196

193(192).
  • Antennal scape swollen; the tarsi exhibiting bilobed segments; hind tarsi with as many segments as the mid-tarsi; the mid-leg coxal cavities narrowly separated; scutellary striole absent ... Nitidulidae
  • Antennal scape not swollen; the tarsi without bilobed segments; hind tarsi with one segment fewer than the mid-tarsi; the mid-leg coxal cavities moderately to widely separated; scutellary striole present ... Sphindidae

194(192).
  • Antennal scape swollen ... Nitidulidae
  • Antennal scape not swollen... 195

195(194).
  • Compound eyes strongly protuberant; the maxillary palps not especially elongated; antennal clubs up to 3 segmented; the tarsi exhibiting bilobed segments; the penultimate segment distinctly shorter than the antepenultimate one ... Byturidae
  • Compound eyes not strongly protuberant; the maxillary palps conspicuously elongated, often longer than the antennae; antennal clubs 4 to 9 segmented; the tarsi without bilobed segments; the penultimate segment not shorter than the antepenultimate one ... Hydrophilidae

196(192).
  • The fore-leg coxal cavities strongly transverse ... 197
  • The fore-leg coxal cavities slightly transverse... 198
  • The fore-leg coxal cavities circular to longer than wide... 199

197(196).
  • Scutellum elevated abruptly and fairly sharply above the mesoscutum in lateral view; hind-leg coxae extending laterally to meet the elytra; the mid-leg coxal cavities moderately to widely separated; beetles terrapin-like in shape, with flattened and clear margins to thorax and elytra; scutellary striole absent ... Peltidae
  • Scutellum not elevated; hind-leg coxae not markedly extended laterally; the mid-leg coxal cavities narrowly separated; beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra; scutellary striole present ... Byturidae

198(196).
  • Prothorax shorter than wide; prothorax at its widest not markedly narrower than the adjoining part of the abdomen; the tarsi without bilobed segments; elytra glabrous; upper surfaces of body glabrous or subglabrous ... Cucujidae
  • Prothorax longer than wide; prothorax at its widest markedly narrower than the adjoining part of the abdomen; the tarsi exhibiting bilobed segments; elytra non-glabrous; upper surfaces of body non-glabrous ... Cleridae

199(196).
  • Mandibles with a well developed mola; adults 1.5 to 5 mm long; adults not predacious; larvae not predacious; tergum 9 of the abdomen of the larva entirely dorsal ... Silvanidae
  • Mandibles without a mola; adults 5.1 to 20 mm long; adults predacious; larvae predacious; tergum 9 of the abdomen of the larva extending to the underside ... Cleridae

200(191).
  • Antennal scape swollen ... Nitidulidae
  • Antennal scape not swollen... 201

201(200).
  • Mandibles with a well developed mola; adults not predacious ... 202
  • Mandibles without a mola; adults predacious ... Cleridae

202(201).
  • The maxillary palps conspicuously elongated, often longer than the antennae; antennal clubs 4 to 9 segmented; the tarsi without bilobed segments; the male external genitalia trilobate; the larvae with abdominal gills ... Hydrophilidae
  • The maxillary palps not especially elongated; antennal clubs up to 3 segmented; the tarsi exhibiting bilobed segments; the male external genitalia cucujiform; the larvae without abdominal gills... 203

203(202).
  • Beetles prognathous; the fore-leg coxal cavities quite widely separated; the fore-leg coxal cavities circular to longer than wide; the claws of the mid-leg tarsi simple; the fore-leg coxal cavities without lateral extensions ... Silvanidae
  • Beetles not prognathous; the fore-leg coxal cavities narrowly separated; the fore-leg coxal cavities strongly transverse; the claws of the mid-leg tarsi one-toothed or bifid; the fore-leg coxal cavities with narrow lateral extensions ... Byturidae

204(191).
  • Beetles not waisted ... 205
  • Beetles somewhat waisted... 207
  • Beetles conspicuously waisted... 210

205(204).
  • Scutellum elevated abruptly and fairly sharply above the mesoscutum in lateral view; the male external genitalia tenebrionoid ... Mycetophagidae
  • Scutellum not elevated; the male external genitalia cucujiform... 206

206(205).
  • The head covered by the thorax; the mid-leg coxal cavities moderately to widely separated; the tarsi without bilobed segments; beetles dorsally somewhat convex ... Corylophidae
  • The head not covered by the thorax; the mid-leg coxal cavities narrowly separated; the tarsi exhibiting bilobed segments; beetles dorsally flattened ... Nitidulidae

207(204).
  • Prothorax shorter than wide ... 208
  • Prothorax about as long as wide ... Cisidae

208(207).
  • The tarsi exhibiting bilobed segments ... Nitidulidae
  • The tarsi without bilobed segments... 209

209(208).
  • Compound eyes strongly protuberant; the maxillary palps not especially elongated; antennal clubs up to 3 segmented; antennae short; the male external genitalia tenebrionoid ... Mycetophagidae
  • Compound eyes not strongly protuberant; the maxillary palps conspicuously elongated, often longer than the antennae; antennal clubs 4 to 9 segmented; antennae very short; the male external genitalia trilobate ... Hydrophilidae

210(204).
  • Beetles terrapin-like in shape, with flattened and clear margins to thorax and elytra ... Peltidae
  • Beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra... 211

211(210).
  • Mandibles with a well developed mola; adults 1.5 to 5 mm long; adults not predacious; larvae not predacious; tergum 9 of the abdomen of the larva entirely dorsal ... Silvanidae
  • Mandibles without a mola; adults 5.1 to 20 mm long; adults predacious; larvae predacious; tergum 9 of the abdomen of the larva extending to the underside ... Cleridae

212(191).
  • The head covered by the thorax; antennal scape swollen; the tarsi without bilobed segments ... Corylophidae
  • The head not covered by the thorax; antennal scape not swollen; the tarsi exhibiting bilobed segments... 213

213(212).
  • Hind-leg coxae contiguous or narrowly separated; the claws of the mid-leg tarsi one-toothed or bifid; hind tarsi 5-segmented; scutellary striole present; hindwings with an anal lobe ... Byturidae
  • Hind-leg coxae widely separated; the claws of the mid-leg tarsi simple; hind tarsi 4-segmented; scutellary striole absent; hindwings without an anal lobe ... Endomychidae

214(191).
  • Cervical sclerites present; prothorax shorter than wide; the fore-leg coxal cavities internally closed by a slender bar; elytra striate; mandibles with well developed prosthecae ... Mycetophagidae
  • Cervical sclerites absent; prothorax about as long as wide; the fore-leg coxal cavities internally open; elytra without striae; mandibles without prosthecae ... Cisidae

215(190).
  • Prothorax shorter than wide ... 216
  • Prothorax about as long as wide ... Hypocopridae
  • Prothorax longer than wide... 222

216(215).
  • The tarsi exhibiting bilobed segments ... 217
  • The tarsi without bilobed segments... 221

217(216).
  • Elytral epipleura reaching to the tips of the elytra ... 218
  • Elytral epipleura falling short of the elytral tips... 220

218(217).
  • Mid-leg tarsi with 5 segments, all conspicuous ... 219
  • Mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one ... Erotylidae
  • Mid-leg tarsi with 4 segments, all easily seen ... Phalacridae
  • Mid-leg tarsi with 3 obvious segments plus a reduced penultimate one ... Endomychidae

219(218).
  • Beetles prognathous; antennal scape not swollen; the fore-leg coxal cavities closed behind externally; the fore-leg coxal cavities internally open; beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra ... Erotylidae
  • Beetles not prognathous; antennal scape swollen; the fore-leg coxal cavities open behind externally; the fore-leg coxal cavities internally closed by a slender bar; beetles terrapin-like in shape, with flattened and clear margins to thorax and elytra ... Phalacridae

220(217).
  • Scutellum elevated abruptly and fairly sharply above the mesoscutum in lateral view; the mid-leg coxal cavities moderately to widely separated ... Cryptophagidae
  • Scutellum not elevated; the mid-leg coxal cavities narrowly separated ... Nitidulidae

221(216).
  • Beetles not waisted; the head covered by the thorax; antennal clubs not comprising two small basal segments and a large terminal one; the penultimate segment distinctly shorter than the antepenultimate one; elytra without striae ... Corylophidae
  • Beetles somewhat waisted; the head not covered by the thorax; antennal clubs spherical, comprising two small basal segments and a large terminal one; the penultimate segment not shorter than the antepenultimate one; elytra striate ... Cerylonidae

222(215).
  • Mandibles with a well developed mola; cervical sclerites absent; the tarsi without bilobed segments; the male external genitalia tenebrionoid; apices of the mandibles of the larva bilobed or bidentate ... Colydiidae
  • Mandibles without a mola; cervical sclerites present; the tarsi exhibiting bilobed segments; the male external genitalia cucujiform; apices of the mandibles of the larva with a single lobe or tooth ... Cleridae

223(189).
  • Mandibles with a well developed mola ... 224
  • Mandibles with a reduced mola ... Derodontidae
  • Mandibles without a mola ... Scolytidae

224(223).
  • The mid-leg cavities open laterally ... 225
  • The mid-leg cavities closed laterally... 229

225(224).
  • Hind-leg coxae extending laterally to meet the elytra ... 226
  • Hind-leg coxae not markedly extended laterally... 228

226(225).
  • Antennae strongly asymmetric; hind-leg coxae posteriorly shaped to receive the retracted femur; hind-leg coxae with a steep transverse declivity against which the femur retracts; the larvae dorsally heavily pigmented or sclerotized ... Heteroceridae
  • Antennae not strongly asymmetric; hind-leg coxae not shaped posteriorly to receive the femur; hind-leg coxae without the steep transverse declivity characteristic of Dryopoidea; the larvae dorsally only very lightly pigmented or sclerotized... 227

227(226).
  • Beetles terrapin-like in shape, with flattened and clear margins to thorax and elytra; the maxillary palps not especially elongated; antennal clubs up to 3 segmented; beetles conspicuously waisted; the male external genitalia cucujiform ... Peltidae
  • Beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra; the maxillary palps conspicuously elongated, often longer than the antennae; antennal clubs 4 to 9 segmented; beetles somewhat waisted; the male external genitalia trilobate ... Hydrophilidae

228(225).
  • Prothorax shorter than wide; the male external genitalia trilobate ... Hydrophilidae
  • Prothorax about as long as wide; the male external genitalia tenebrionoid ... Cisidae
  • Prothorax longer than wide; the male external genitalia cucujiform ... Silvanidae

229(224).
  • Cervical sclerites present; prothorax shorter than wide; the tarsi exhibiting bilobed segments; the male external genitalia cucujiform ... Erotylidae
  • Cervical sclerites absent; prothorax longer than wide; the tarsi without bilobed segments; the male external genitalia tenebrionoid ... Colydiidae

230(189).
  • The mid-leg cavities open laterally; hind-leg coxae extending laterally to meet the elytra; cervical sclerites present; the fore-leg coxal cavities strongly transverse; beetles terrapin-like in shape, with flattened and clear margins to thorax and elytra ... Peltidae
  • The mid-leg cavities closed laterally; hind-leg coxae not markedly extended laterally; cervical sclerites absent; the fore-leg coxal cavities circular to longer than wide; beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra ... Colydiidae

231(167).
  • The hind-leg coxae much enlarged; cervical sclerites absent; compound eyes accommodating the antennae in an anterior notch; labial palps of the larva absent or non-segmented ... Bruchidae
  • The hind-leg coxae not much enlarged; cervical sclerites present; compound eyes not accommodating the antennae in a notch; labial palps of the larva present and segmented... 232

232(231).
  • The fore-leg coxal cavities internally open ... Ptilodactylidae
  • The fore-leg coxal cavities internally closed by a slender bar ... Chrysomelidae
  • The fore-leg coxal cavities broadly closed internally ... Chrysomelidae

233(26).
  • Mid-leg tarsi with 4 segments, all easily seen ... 234
  • Mid-leg tarsi with 3 obvious segments plus a reduced penultimate one... 236
  • Mid-leg tarsi with 3 segments, all easily seen... 237

234(233).
  • The mid-leg cavities open laterally; the fore-leg coxal cavities slightly transverse ... Cisidae
  • The mid-leg cavities closed laterally; the fore-leg coxal cavities circular to longer than wide... 235

235(234).
  • Beetles somewhat waisted; antennal scape swollen; antennal insertions visible from above; prothorax shorter than wide; antennal clubs spherical, comprising two small basal segments and a large terminal one ... Cerylonidae
  • Beetles conspicuously waisted; antennal scape not swollen; antennal insertions hidden from above; prothorax longer than wide; antennal clubs not comprising two small basal segments and a large terminal one ... Colydiidae

236(233).
  • The claws of the mid-leg tarsi simple ... Endomychidae
  • The claws of the mid-leg tarsi one-toothed or bifid ... Coccinellidae

237(233).
  • The hind-leg coxae much enlarged; hind-leg coxae posteriorly shaped to receive the retracted femur; hind-leg coxae produced behind into flat plates which conceal the hind femora when retracted ... Ptiliidae
  • The hind-leg coxae not much enlarged; hind-leg coxae not shaped posteriorly to receive the femur; hind-leg coxae not concealing the hind femora... 238

238(237).
  • The mid-leg cavities open laterally; the fore-leg coxal cavities slightly transverse ... Cisidae
  • The mid-leg cavities closed laterally; the fore-leg coxal cavities circular to longer than wide... 239

239(238).
  • Beetles conspicuously necked ... Lathridiidae
  • Beetles not necked... 240

240(239).
  • Beetles somewhat waisted; antennal scape swollen; antennal clubs spherical, comprising two small basal segments and a large terminal one ... Cerylonidae
  • Beetles conspicuously waisted; antennal scape not swollen; antennal clubs not comprising two small basal segments and a large terminal one... 241

241(240).
  • The fore-leg coxal cavities internally open; elytra dull; the male external genitalia tenebrionoid; tergum 9 of the abdomen of the larva extending to the underside ... Colydiidae
  • The fore-leg coxal cavities broadly closed internally; elytra glossy; the male external genitalia cucujiform; tergum 9 of the abdomen of the larva entirely dorsal ... Merophysiidae

242(25).
  • Antennae filiform ... 243
  • Antennae gradually expanding towards the apex ... Silphidae
  • Antennae clubbed... 262
  • Antennae serrate... 270
  • Antennae pectinate ... Rhipiphoridae
  • Antennae plumose or biplumose ... Rhipiphoridae

243(242).
  • Abdominal sternites all articulated and moveable ... 244
  • Abdominal sternites comprising both fused and moveable components... 261

244(243).
  • Mid-leg tarsi with 5 segments, all conspicuous ... 245
  • Mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one... 258
  • Mid-leg tarsi with 4 segments, all easily seen... 260
  • Mid-leg tarsi with 3 obvious segments plus a reduced penultimate one ... Staphylinidae
  • Mid-leg tarsi with 3 segments, all easily seen ... Staphylinidae

245(244).
  • Elytra exposing no more than part of the terminal tergite ... 246
  • Elytra exposing at least one but fewer than three complete abdominal tergites... 250
  • Elytra exposing at least three complete abdominal tergites... 254

246(245).
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 5; hind tarsi with as many segments as the mid-tarsi; hind tarsi 5-segmented ... 247
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 4; hind tarsi with one segment fewer than the mid-tarsi; hind tarsi 4-segmented ... Meloïdae

247(246).
  • Elytra meeting along the length of the mid-line; apices of the mandibles of the larva bilobed or bidentate ... 248
  • Elytra not meeting along the full length of the mid-line; apices of the mandibles of the larva with a single lobe or tooth... 249

248(247).
  • The mid-leg cavities open laterally; mandibles without a mola; the mesocoxae separated by less than the shortest diameter of the cavity; the male external genitalia cucujiform; tergum 9 of the abdomen of the larva extending to the underside ... Melyridae
  • The mid-leg cavities closed laterally; mandibles with a well developed mola; the mesocoxae separated by more than the shortest diameter of the cavity; the male external genitalia staphylinoid; tergum 9 of the abdomen of the larva entirely dorsal ... Scaphidiidae

249(247).
  • The head covered by the thorax; prothorax shorter than wide; the tarsi exhibiting bilobed segments; the claws of the mid-leg tarsi without an associated empodium; elytra not truncate ... Lampyridae (males)
  • The head not covered by the thorax; prothorax longer than wide; the tarsi without bilobed segments; the claws of the mid-leg tarsi with an empodium between them; elytra truncate ... Lymexylidae

250(245).
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 5; hind tarsi with as many segments as the mid-tarsi; hind tarsi 5-segmented ... 251
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 4; hind tarsi with one segment fewer than the mid-tarsi; hind tarsi 4-segmented ... Meloïdae

251(250).
  • Elytra meeting along the length of the mid-line; apices of the mandibles of the larva bilobed or bidentate ... 252
  • Elytra not meeting along the full length of the mid-line; apices of the mandibles of the larva with a single lobe or tooth... 253

252(251).
  • The mid-leg cavities open laterally; mandibles without a mola; the mesocoxae separated by less than the shortest diameter of the cavity; the male external genitalia cucujiform; tergum 9 of the abdomen of the larva extending to the underside ... Melyridae
  • The mid-leg cavities closed laterally; mandibles with a well developed mola; the mesocoxae separated by more than the shortest diameter of the cavity; the male external genitalia staphylinoid; tergum 9 of the abdomen of the larva entirely dorsal ... Scaphidiidae

253(251).
  • The head covered by the thorax; prothorax shorter than wide; the tarsi exhibiting bilobed segments; the claws of the mid-leg tarsi without an associated empodium; elytra not truncate ... Lampyridae (males)
  • The head not covered by the thorax; prothorax longer than wide; the tarsi without bilobed segments; the claws of the mid-leg tarsi with an empodium between them; elytra truncate ... Lymexylidae

254(245).
  • The head covered by the thorax ... Lampyridae (males)
  • The head not covered by the thorax... 255

255(254).
  • Elytra meeting along the length of the mid-line ... 256
  • Elytra not meeting along the full length of the mid-line... 257

256(255).
  • Antennae with the first segment (scape) much-elongated; the male external genitalia staphylinoid; tergum 9 of the abdomen of the larva entirely dorsal ... Staphylinidae
  • Antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); the male external genitalia cucujiform; tergum 9 of the abdomen of the larva extending to the underside ... Melyridae

257(255).
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 5; prothorax longer than wide; prothorax at its widest not markedly narrower than the adjoining part of the abdomen; hind tarsi with as many segments as the mid-tarsi; hind tarsi 5-segmented ... Lymexylidae
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 4; prothorax shorter than wide; prothorax at its widest markedly narrower than the adjoining part of the abdomen; hind tarsi with one segment fewer than the mid-tarsi; hind tarsi 4-segmented ... Meloïdae

258(244).
  • Abdominal sternites 5 ... Cerambycidae
  • Abdominal sternites 6 to 7... 259

259(258).
  • Antennae with the first segment (scape) much-elongated; the male external genitalia staphylinoid; tergum 9 of the abdomen of the larva entirely dorsal ... Staphylinidae
  • Antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); the male external genitalia cucujiform; tergum 9 of the abdomen of the larva extending to the underside ... Melyridae

260(244).
  • Antennae with the first segment (scape) much-elongated; the male external genitalia staphylinoid; tergum 9 of the abdomen of the larva entirely dorsal ... Staphylinidae
  • Antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); the male external genitalia cucujiform; tergum 9 of the abdomen of the larva extending to the underside ... Melyridae

261(243).
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 5; elytra meeting along the length of the mid-line; elytra smooth; the fore-leg coxal cavities internally open; hind tarsi with as many segments as the mid-tarsi ... Melyridae
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 4; elytra not meeting along the full length of the mid-line; elytra ribbed; the fore-leg coxal cavities internally closed by a slender bar; hind tarsi with one segment fewer than the mid-tarsi ... Oedemeridae

262(242).
  • Mid-leg tarsi with 5 segments, all conspicuous ... 263
  • Mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one ... Staphylinidae
  • Mid-leg tarsi with 4 segments, all easily seen ... Staphylinidae
  • Mid-leg tarsi with 3 obvious segments plus a reduced penultimate one ... Staphylinidae
  • Mid-leg tarsi with 3 segments, all easily seen... 268

263(262).
  • Elytra exposing no more than part of the terminal tergite ... 264
  • Elytra exposing at least one but fewer than three complete abdominal tergites... 266
  • Elytra exposing at least three complete abdominal tergites... 267

264(263).
  • The mid-leg cavities open laterally; the fore-leg coxal cavities strongly transverse; antennal clubs up to 3 segmented; apices of the mandibles of the larva with a single lobe or tooth ... 265
  • The mid-leg cavities closed laterally; the fore-leg coxal cavities circular to longer than wide; antennal clubs 4 to 9 segmented; apices of the mandibles of the larva bilobed or bidentate ... Scaphidiidae

265(264).
  • Antennae strongly asymmetric; antennae not elbowed; antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); the prosternal process incomplete; the fore-leg coxal cavities medianly confluent ... Silphidae
  • Antennae not strongly asymmetric; antennae conspicuously elbowed; antennae with the first segment (scape) much-elongated; the prosternal process complete; the fore-leg coxal cavities quite widely separated ... Histeridae

266(263).
  • The mid-leg cavities open laterally; antennae conspicuously elbowed; antennae with the first segment (scape) much-elongated; antennal clubs up to 3 segmented; the fore-leg coxal cavities strongly transverse ... Histeridae
  • The mid-leg cavities closed laterally; antennae not elbowed; antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); antennal clubs 4 to 9 segmented; the fore-leg coxal cavities circular to longer than wide ... Scaphidiidae

267(263).
  • Beetles conspicuously necked; antennae not strongly asymmetric; antennae with the first segment (scape) much-elongated; prothorax longer than wide ... Staphylinidae
  • Beetles not necked; antennae strongly asymmetric; antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); prothorax shorter than wide ... Silphidae

268(262).
  • The hind-leg coxae much enlarged; beetles not necked; hind-leg coxae posteriorly shaped to receive the retracted femur; hind-leg coxae produced behind into flat plates which conceal the hind femora when retracted ... Ptiliidae
  • The hind-leg coxae not much enlarged; beetles conspicuously necked; hind-leg coxae not shaped posteriorly to receive the femur; hind-leg coxae not concealing the hind femora... 269

269(268).
  • Antennae with the first segment (scape) much-elongated; prothorax longer than wide ... Staphylinidae
  • Antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); prothorax about as long as wide ... Pselaphidae

270(242).
  • Elytra meeting along the length of the mid-line; body somewhat flattened; the last abdominal segment of the larva with cerci; stemmata present; apices of the mandibles of the larva bilobed or bidentate ... Melyridae
  • Elytra not meeting along the full length of the mid-line; body circular in cross-section; the last abdominal segment of the larva without cerci; stemmata absent; apices of the mandibles of the larva with a single lobe or tooth ... Lymexylidae

271(24).
  • Antennae filiform ... 272
  • Antennae clubbed... 290
  • Antennae serrate... 292
  • Antennae pectinate ... Lycidae

272(271).
  • Scutellum conspicuous ... 273
  • Scutellum highly reduced... 285
  • Scutellum absent... 288

273(272).
  • Beetles luminescent from distal abdominal sternites ... 274
  • Beetles not luminescent... 275

274(273).
  • Elytra present ... Lampyridae (males)
  • Elytra absent... Lampyridae (females)

275(273).
  • Elytra covering most to all of the abdomen ... 276
  • Elytra short, exposing several terminal abdominal tergites... 280

276(275).
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 5; hind tarsi with as many segments as the mid-tarsi ... 277
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 4; hind tarsi with one segment fewer than the mid-tarsi ... Meloïdae

277(276).
  • Beetles exhibiting bright ‘warning colours’ ... Lycidae
  • Beetles without ‘warning colouration’... 278

278(277).
  • The head covered by the thorax; the larvae dorsally heavily pigmented or sclerotized; the abdomen of the larva with anterior and 8th-segmental spiracles borne at the ends of a series of spiracular tubes ... Lampyridae (males)
  • The head not covered by the thorax; the larvae dorsally only very lightly pigmented or sclerotized; the abdomen of the larva without spiracular tubes... 279

279(278).
  • The labrum at least partly visible in antero-dorsal view; abdominal segment 8 apparently without functional spiracles; the labrum and head capsule of the larva separated by a complete suture; apices of the mandibles of the larva bilobed or bidentate; tergum 9 of the abdomen of the larva extending to the underside ... Melyridae
  • The labrum concealed beneath the clypeus; abdominal segment 8 with apparently functional spiracles; the labrum and head capsule of the larva completely fused, with no suture apparent; apices of the mandibles of the larva with a single lobe or tooth; tergum 9 of the abdomen of the larva entirely dorsal ... Cantharidae

280(275).
  • Prothorax shorter than wide ... 281
  • Prothorax about as long as wide... 283
  • Prothorax longer than wide... 284

281(280).
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 5; hind tarsi with as many segments as the mid-tarsi; hind tarsi 5-segmented; tergum 9 of the abdomen of the larva extending to the underside ... 282
  • Apparent tarsal segmentation (fore-, mid-, hind-leg: ignoring any small cylindrical segments obscured by lobes on those preceding them) 5, 5, 4; hind tarsi with one segment fewer than the mid-tarsi; hind tarsi 4-segmented; tergum 9 of the abdomen of the larva entirely dorsal ... Meloïdae

282(281).
  • The head covered by the thorax; elytra not meeting along the full length of the mid-line; the male external genitalia trilobate; the larvae dorsally heavily pigmented or sclerotized; the labrum and head capsule of the larva completely fused, with no suture apparent ... Lampyridae (males)
  • The head not covered by the thorax; elytra meeting along the length of the mid-line; the male external genitalia cucujiform; the larvae dorsally only very lightly pigmented or sclerotized; the labrum and head capsule of the larva separated by a complete suture ... Melyridae

283(280).
  • The labrum at least partly visible in antero-dorsal view; abdominal segment 8 apparently without functional spiracles; the labrum and head capsule of the larva separated by a complete suture; apices of the mandibles of the larva bilobed or bidentate; tergum 9 of the abdomen of the larva extending to the underside ... Melyridae
  • The labrum concealed beneath the clypeus; abdominal segment 8 with apparently functional spiracles; the labrum and head capsule of the larva completely fused, with no suture apparent; apices of the mandibles of the larva with a single lobe or tooth; tergum 9 of the abdomen of the larva entirely dorsal ... Cantharidae

284(280).
  • Antennae with the first segment (scape) much-elongated; elytra meeting along the length of the mid-line; the male external genitalia staphylinoid; tergum 9 of the abdomen of the larva entirely dorsal ... Staphylinidae
  • Antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); elytra not meeting along the full length of the mid-line; the male external genitalia cucujiform; tergum 9 of the abdomen of the larva extending to the underside ... Lymexylidae

285(272).
  • Beetles luminescent from distal abdominal sternites; the head covered by the thorax ... Lampyridae (females)
  • Beetles not luminescent; the head not covered by the thorax... 286

286(285).
  • Beetles conspicuously necked; the tarsi without bilobed segments; the penultimate segment not shorter than the antepenultimate one; elytra present; tergum 9 of the abdomen of the larva entirely dorsal ... 287
  • Beetles not necked; the tarsi exhibiting bilobed segments; the penultimate segment distinctly shorter than the antepenultimate one; elytra absent; tergum 9 of the abdomen of the larva extending to the underside... Drilidae (females)

287(286).
  • Antennae with the first segment (scape) much-elongated; prothorax longer than wide; prothorax at its widest not markedly narrower than the adjoining part of the abdomen; elytra meeting along the length of the mid-line; elytra truncate ... Staphylinidae
  • Antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); prothorax shorter than wide; prothorax at its widest markedly narrower than the adjoining part of the abdomen; elytra not meeting along the full length of the mid-line; elytra not truncate ... Meloïdae

288(272).
  • Beetles luminescent from distal abdominal sternites; beetles not necked; the head covered by the thorax; the tarsi exhibiting bilobed segments; elytra absent ... Lampyridae (females)
  • Beetles not luminescent; beetles conspicuously necked; the head not covered by the thorax; the tarsi without bilobed segments; elytra present... 289

289(288).
  • Antennae with the first segment (scape) much-elongated; prothorax longer than wide; prothorax at its widest not markedly narrower than the adjoining part of the abdomen; elytra meeting along the length of the mid-line; elytra truncate ... Staphylinidae
  • Antennae without a much-elongated scape (though it is often longer than the adjoining, second segment); prothorax shorter than wide; prothorax at its widest markedly narrower than the adjoining part of the abdomen; elytra not meeting along the full length of the mid-line; elytra not truncate ... Meloïdae

290(271).
  • Elytra covering most to all of the abdomen; beetles not necked; antennae without a much-elongated scape (though it is often longer than the adjoining, second segment) ... 291
  • Elytra short, exposing several terminal abdominal tergites; beetles conspicuously necked; antennae with the first segment (scape) much-elongated ... Staphylinidae

291(290).
  • Beetles exhibiting bright ‘warning colours’; the labrum and head capsule of the larva completely fused, with no suture apparent; the labium of the larva without ligula between the palps ... Lycidae
  • Beetles without ‘warning colouration’; the labrum and head capsule of the larva separated by a complete suture; the labium of the larva with a short ligula between the palps ... Dermestidae

292(271).
  • Elytra covering most to all of the abdomen ... 293
  • Elytra short, exposing several terminal abdominal tergites... 294

293(292).
  • The mid-leg coxae countersunk in ‘mesocoxal cavities’; beetles without ‘warning colouration’; elytra smooth; abdominal segment 8 apparently without functional spiracles; apices of the mandibles of the larva bilobed or bidentate ... Melyridae
  • The mid-leg coxae attached externally, in the absence of mesocoxal cavities; beetles exhibiting bright ‘warning colours’; elytra ribbed; abdominal segment 8 with apparently functional spiracles; apices of the mandibles of the larva with a single lobe or tooth ... Lycidae

294(292).
  • Elytra meeting along the length of the mid-line; body somewhat flattened; stemmata present; apices of the mandibles of the larva bilobed or bidentate; the last abdominal segment of the larva with cerci ... Melyridae
  • Elytra not meeting along the full length of the mid-line; body circular in cross-section; stemmata absent; apices of the mandibles of the larva with a single lobe or tooth; the last abdominal segment of the larva without cerci ... Lymexylidae


To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. Insects of Britain and Ireland: the families of Coleoptera. Version: 16th May 2016. delta-intkey.com’.

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