British Insects: the Families of Diptera

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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).
  • Antennae ‘simple’ (basic structure filiform, moniliform or linear, the segments more or less all alike; not evidently ‘reduced’ or ‘modified’) ... 2
  • Antennae ‘modified’ (not filiform, variously reduced and/or complicated, with markedly differentiated segments)... 82

2(1).
  • Thorax with the dorsal suture just in front of the wing bases continuous across the middle ... 3
  • Thorax without a continuous dorsal suture... 7

3(2).
  • The dorsal suture deeply V-shaped ... 4
  • The dorsal suture deeply U-shaped ... Ptychopteridae
  • The dorsal suture neither V-shaped nor U-shaped ... Cylindrotomidae

4(3).
  • The legs readily shed ... 5
  • The legs not readily shed... 6

5(4).
  • The costa extending around the entire wing ... Tipulidae
  • The costa not extending around the entire wing ... Limoniidae

6(4).
  • The costa extending around the entire wing ... Trichoceridae
  • The costa not extending around the entire wing ... Pediciidae

7(2).
  • Posterior division of pronotum with one or more long bristles ... 8
  • Posterior division of pronotum without long bristles... 40

8(7).
  • Antennae long and threadlike ... 9
  • Antennae short and stout... 24

9(8).
  • The costa extending around the entire wing ... 10
  • The costa not extending around the entire wing... 14

10(9).
  • stilt-legged (legs long and thin) ... 11
  • not stilt-legged (legs of about average length and thickness)... 13

11(10).
  • Eyes asymmetric, nearly or quite connected above the antennae; the larvae terrestrial ... Cecidomyiidae
  • Eyes rounded, well separated; the larvae aquatic... 12

12(11).
  • The maxillary palps porrect ... Culicidae
  • The maxillary palps drooping ... Dixidae

13(10).
  • Eyes asymmetric, nearly or quite connected above the antennae; mouthparts of adults functional ... Thaumaleidae
  • Eyes rounded, well separated; mouthparts of adults non-functional ... Psychodidae

14(9).
  • Ocelli present ... 15
  • Ocelli absent... 21

15(14).
  • Media and cubitus veins connected via a cross vein or by a fusion ... 16
  • Media and cubitus veins not connected by a cross-vein or a fusion... 18

16(15).
  • Wings with a discal cell; wings patterned ... Anisopodidae
  • Wings without a discal cell; wings unpatterned... 17

17(16).
  • Eyes asymmetric, nearly or quite connected above the antennae; not stilt-legged (legs of about average length and thickness); tibiae without spurs ... Scatopsidae
  • Eyes rounded, well separated; stilt-legged (legs long and thin); tibiae spurred ... Ditomyiidae

18(15).
  • Wing veins reaching the margin up to 6 ... 19
  • Wing veins reaching the margin 7 to 8 ... Scatopsidae
  • Wing veins reaching the margin 9 to 11... 20
  • Wing veins reaching the margin 12 or more ... Mycetophilidae

19(18).
  • stilt-legged (legs long and thin); tibiae spurred ... Sciaridae
  • not stilt-legged (legs of about average length and thickness); tibiae without spurs ... Scatopsidae

20(18).
  • Wings with a discal cell; wing vein 7 falling short of the wing margin ... Anisopodidae
  • Wings without a discal cell; wing vein 7 reaching the wing margin ... Mycetophilidae

21(14).
  • stilt-legged (legs long and thin) ... 22
  • not stilt-legged (legs of about average length and thickness)... 23

22(21).
  • Mandibles present ... Chaoboridae
  • Mandibles absent ... Chironomidae

23(21).
  • Sub-costa reaching the costa independently of vein 1 ... Simuliidae
  • Sub-costa terminating blind ... Ceratopogonidae

24(8).
  • Ocelli present ... 25
  • Ocelli absent... 32

25(24).
  • hairy bodied ... 26
  • not hairy bodied... 29

26(25).
  • Wings with a discal cell; wings patterned ... Anisopodidae
  • Wings without a discal cell; wings unpatterned... 27

27(26).
  • stilt-legged (legs long and thin) ... 28
  • not stilt-legged (legs of about average length and thickness) ... Bibionidae

28(27).
  • Eyes asymmetric, nearly or quite connected above the antennae; the costa extending around the entire wing ... Cecidomyiidae
  • Eyes rounded, well separated; the costa not extending around the entire wing ... Ditomyiidae

29(25).
  • Wings with a discal cell; wings patterned ... Anisopodidae
  • Wings without a discal cell; wings unpatterned... 30

30(29).
  • Eyes asymmetric, nearly or quite connected above the antennae ... 31
  • Eyes rounded, well separated ... Ditomyiidae

31(30).
  • The costa extending around the entire wing; sub-costa absent or only dubiously identifiable; stilt-legged (legs long and thin) ... Cecidomyiidae
  • The costa not extending around the entire wing; sub-costa apparent and at least partially free of vein 1; not stilt-legged (legs of about average length and thickness) ... Scatopsidae

32(24).
  • stilt-legged (legs long and thin) ... 33
  • not stilt-legged (legs of about average length and thickness)... 37

33(32).
  • The costa extending around the entire wing ... 34
  • The costa not extending around the entire wing... 36

34(33).
  • Eyes asymmetric, nearly or quite connected above the antennae; the larvae terrestrial ... Cecidomyiidae
  • Eyes rounded, well separated; the larvae aquatic... 35

35(34).
  • The maxillary palps porrect ... Culicidae
  • The maxillary palps drooping ... Dixidae

36(33).
  • Mandibles present ... Chaoboridae
  • Mandibles absent ... Chironomidae

37(32).
  • The costa extending around the entire wing ... 38
  • The costa not extending around the entire wing... 39

38(37).
  • Eyes asymmetric, nearly or quite connected above the antennae; mouthparts of adults functional ... Thaumaleidae
  • Eyes rounded, well separated; mouthparts of adults non-functional ... Psychodidae

39(37).
  • Sub-costa reaching the costa independently of vein 1 ... Simuliidae
  • Sub-costa terminating blind ... Ceratopogonidae

40(7).
  • Ocelli present ... 41
  • Ocelli absent... 74

41(40).
  • Antennae long and threadlike ... 42
  • Antennae short and stout... 57

42(41).
  • Media vein with a distinct basal section ... 43
  • Media vein fused basally with the radius for a short distance... 51

43(42).
  • Eyes asymmetric, nearly or quite connected above the antennae ... 44
  • Eyes rounded, well separated... 47

44(43).
  • Wings with a discal cell; wings patterned ... Anisopodidae
  • Wings without a discal cell; wings unpatterned... 45

45(44).
  • stilt-legged (legs long and thin) ... 46
  • not stilt-legged (legs of about average length and thickness) ... Scatopsidae

46(45).
  • The costa extending around the entire wing; sub-costa absent or only dubiously identifiable ... Cecidomyiidae
  • The costa not extending around the entire wing; sub-costa apparent and at least partially free of vein 1 ... Sciaridae

47(43).
  • Media and cubitus veins connected via a cross vein or by a fusion ... 48
  • Media and cubitus veins not connected by a cross-vein or a fusion... 50

48(47).
  • Wings with a discal cell; wings patterned ... Anisopodidae
  • Wings without a discal cell; wings unpatterned... 49

49(48).
  • m-cu well before r-m ... Bolitophilidae
  • m-cu and r-m cross-veins close ... Diadocidiidae

50(47).
  • Wings with a discal cell; wing vein 7 falling short of the wing margin ... Anisopodidae
  • Wings without a discal cell; wing vein 7 reaching the wing margin ... Mycetophilidae

51(42).
  • Wing veins reaching the margin up to 6 ... 52
  • Wing veins reaching the margin 7 to 8... 54
  • Wing veins reaching the margin 9 to 11... 55
  • Wing veins reaching the margin 12 or more ... Mycetophilidae

52(51).
  • stilt-legged (legs long and thin) ... 53
  • not stilt-legged (legs of about average length and thickness) ... Scatopsidae

53(52).
  • The costa extending around the entire wing; sub-costa absent or only dubiously identifiable ... Cecidomyiidae
  • The costa not extending around the entire wing; sub-costa apparent and at least partially free of vein 1 ... Sciaridae

54(51).
  • stilt-legged (legs long and thin); eyes rounded, well separated; sub-costa reaching the costa independently of vein 1; tibiae spurred ... Keroplatidae
  • not stilt-legged (legs of about average length and thickness); eyes asymmetric, nearly or quite connected above the antennae; sub-costa terminating blind; tibiae without spurs ... Scatopsidae

55(51).
  • Wings with a discal cell ... Anisopodidae
  • Wings without a discal cell... 56

56(55).
  • Media and cubitus veins connected via a cross vein or by a fusion ... Keroplatidae
  • Media and cubitus veins not connected by a cross-vein or a fusion ... Mycetophilidae

57(41).
  • Media vein with a distinct basal section ... 58
  • Media vein fused basally with the radius for a short distance... 67

58(57).
  • hairy bodied ... 59
  • not hairy bodied... 63

59(58).
  • Wings with a discal cell; wings patterned ... Anisopodidae
  • Wings without a discal cell; wings unpatterned... 60

60(59).
  • stilt-legged (legs long and thin) ... 61
  • not stilt-legged (legs of about average length and thickness) ... Bibionidae

61(60).
  • Eyes asymmetric, nearly or quite connected above the antennae; the costa extending around the entire wing ... Cecidomyiidae
  • Eyes rounded, well separated; the costa not extending around the entire wing... 62

62(61).
  • m-cu well before r-m ... Bolitophilidae
  • m-cu and r-m cross-veins close ... Diadocidiidae

63(58).
  • Wings with a discal cell; wings patterned ... Anisopodidae
  • Wings without a discal cell; wings unpatterned... 64

64(63).
  • Eyes asymmetric, nearly or quite connected above the antennae ... 65
  • Eyes rounded, well separated... 66

65(64).
  • stilt-legged (legs long and thin); the costa extending around the entire wing; sub-costa absent or only dubiously identifiable ... Cecidomyiidae
  • not stilt-legged (legs of about average length and thickness); the costa not extending around the entire wing; sub-costa apparent and at least partially free of vein 1 ... Scatopsidae

66(64).
  • m-cu well before r-m ... Bolitophilidae
  • m-cu and r-m cross-veins close ... Diadocidiidae

67(57).
  • hairy bodied ... 68
  • not hairy bodied... 71

68(67).
  • Wings with a discal cell; wings patterned ... Anisopodidae
  • Wings without a discal cell; wings unpatterned... 69

69(68).
  • stilt-legged (legs long and thin) ... 70
  • not stilt-legged (legs of about average length and thickness) ... Bibionidae

70(69).
  • Eyes asymmetric, nearly or quite connected above the antennae; the costa extending around the entire wing; sub-costa absent or only dubiously identifiable ... Cecidomyiidae
  • Eyes rounded, well separated; the costa not extending around the entire wing; sub-costa apparent and at least partially free of vein 1 ... Keroplatidae

71(67).
  • Wings with a discal cell; wings patterned ... Anisopodidae
  • Wings without a discal cell; wings unpatterned... 72

72(71).
  • Eyes asymmetric, nearly or quite connected above the antennae ... 73
  • Eyes rounded, well separated ... Keroplatidae

73(72).
  • stilt-legged (legs long and thin); the costa extending around the entire wing; sub-costa absent or only dubiously identifiable ... Cecidomyiidae
  • not stilt-legged (legs of about average length and thickness); the costa not extending around the entire wing; sub-costa apparent and at least partially free of vein 1 ... Scatopsidae

74(40).
  • The costa extending around the entire wing ... 75
  • The costa not extending around the entire wing... 79

75(74).
  • stilt-legged (legs long and thin) ... 76
  • not stilt-legged (legs of about average length and thickness)... 78

76(75).
  • Eyes asymmetric, nearly or quite connected above the antennae; the larvae terrestrial ... Cecidomyiidae
  • Eyes rounded, well separated; the larvae aquatic... 77

77(76).
  • The maxillary palps porrect ... Culicidae
  • The maxillary palps drooping ... Dixidae

78(75).
  • Eyes asymmetric, nearly or quite connected above the antennae; mouthparts of adults functional ... Thaumaleidae
  • Eyes rounded, well separated; mouthparts of adults non-functional ... Psychodidae

79(74).
  • stilt-legged (legs long and thin) ... 80
  • not stilt-legged (legs of about average length and thickness)... 81

80(79).
  • Mandibles present ... Chaoboridae
  • Mandibles absent ... Chironomidae

81(79).
  • Sub-costa reaching the costa independently of vein 1 ... Simuliidae
  • Sub-costa terminating blind ... Ceratopogonidae

82(1).
  • Wings exhibiting a ‘vena spuria’ ... Syrphidae
  • Wings without a ‘vena spuria’... 83

83(82).
  • The face in lateral view deeply excavated between the antennae and the edge of the mouth ... 84
  • The face in lateral view not deeply excavated between the antennae and the edge of the mouth... 87

84(83).
  • Hind tibiae with strong bristles in the basal 4/5 ... 85
  • Hind tibiae without strong bristles in the basal 4/5... 86

85(84).
  • Wing vein 6 reaching the wing margin; the costa unbroken; the larvae aquatic ... Coelopidae
  • Wing vein 6 falling short of the wing margin; the costa with two breaks; the larvae terrestrial ... Sphaeroceridae

86(84).
  • Wing vein 6 reaching the wing margin; the costa unbroken ... Dryomyzidae
  • Wing vein 6 falling short of the wing margin; the costa with two breaks ... Sphaeroceridae

87(83).
  • The second antennal segment when viewed from the outside with a triangular projection extending partway over the third and often with an upper and a lower bristle ... Clusiidae
  • The second antennal segment when viewed from the outside normal, with no extension over the third... 88

88(87).
  • The hind tarsi having the basal three or four segments flattened and dilated ... Platypezidae
  • The hind tarsi normal (not flattened and dilated)... 89

89(88).
  • Hind tibiae with strong bristles in the basal 4/5 ... 90
  • Hind tibiae without strong bristles in the basal 4/5... 188

90(89).
  • Thorax with the dorsal suture just in front of the wing bases continuous across the middle ... 91
  • Thorax without a continuous dorsal suture... 146

91(90).
  • The back of the head rounded, with fine pale hairs below ... 92
  • The back of the head markedly flattened above, without fine pale hairs below... 119

92(91).
  • The post-humeral bristle located on the thorax higher than or level with the pre-sutural bristle ... 93
  • The post-humeral bristle located lower on the thorax than the pre-sutural bristle... 106

93(92).
  • Mouthparts adapted for piercing ... 94
  • Mouthparts non-piercing... 100

94(93).
  • Antennae 1 segmented ... Hippoboscidae
  • Antennae 2 segmented... 95
  • Antennae 3 segmented... 96
  • Antennae 4 to 5 segmented ... Fanniidae
  • Antennae 6 to 7 segmented ... Fanniidae

95(94).
  • winged; life style of species non-parasitic ... Fanniidae
  • wingless; life style of species parasitic ... Nycteribiidae

96(94).
  • Wings exhibiting a sharp bend in vein 4 ... 97
  • Wings without a sharp bend in vein 4... 98

97(96).
  • Hypopleural bristles present ... Tachinidae
  • Hypopleural bristles absent ... Muscidae

98(96).
  • Wings with a well developed lower calypter ... 99
  • Wings with the lower calypter much reduced or absent ... Scathophagidae

99(98).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4 ... Muscidae
  • Wings without a sub-apical cell ... Fanniidae

100(93).
  • Wings exhibiting a sharp bend in vein 4 ... 101
  • Wings without a sharp bend in vein 4... 103

101(100).
  • Hypopleural bristles present ... 102
  • Hypopleural bristles absent ... Muscidae

102(101).
  • Postscutellum present and well developed ... Tachinidae
  • Postscutellum absent or weakly developed ... Sarcophagidae

103(100).
  • Wings with a well developed lower calypter ... 104
  • Wings with the lower calypter much reduced or absent ... Scathophagidae

104(103).
  • Hypopleural bristles present ... Rhinophoridae
  • Hypopleural bristles absent... 105

105(104).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4 ... Muscidae
  • Wings without a sub-apical cell ... Fanniidae

106(92).
  • winged ... 107
  • wingless... 118

107(106).
  • Wings exhibiting a sharp bend in vein 4 ... 108
  • Wings without a sharp bend in vein 4... 110

108(107).
  • Hypopleural bristles present ... 109
  • Hypopleural bristles absent ... Muscidae

109(108).
  • Postscutellum present and well developed ... Tachinidae
  • Postscutellum absent or weakly developed ... Calliphoridae

110(107).
  • Mouthparts adapted for piercing ... 111
  • Mouthparts non-piercing... 115

111(110).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4 ... Muscidae
  • Wings without a sub-apical cell... 112

112(111).
  • Ocelli present ... 113
  • Ocelli absent... 114

113(112).
  • Wings with a well developed lower calypter ... Fanniidae
  • Wings with the lower calypter much reduced or absent ... Scathophagidae

114(112).
  • Wing vein 6 reaching the wing margin; life style of species parasitic ... Hippoboscidae
  • Wing vein 6 falling short of the wing margin; life style of species non-parasitic ... Fanniidae

115(110).
  • Wings with a well developed lower calypter ... 116
  • Wings with the lower calypter much reduced or absent ... Scathophagidae

116(115).
  • Hypopleural bristles present ... Rhinophoridae
  • Hypopleural bristles absent... 117

117(116).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4 ... Muscidae
  • Wings without a sub-apical cell ... Fanniidae

118(106).
  • Antennae 1 segmented ... Hippoboscidae
  • Antennae 2 segmented ... Nycteribiidae

119(91).
  • The post-humeral bristle located on the thorax higher than or level with the pre-sutural bristle ... 120
  • The post-humeral bristle located lower on the thorax than the pre-sutural bristle... 134

120(119).
  • Mouthparts adapted for piercing ... 121
  • Mouthparts non-piercing... 128

121(120).
  • winged ... 122
  • wingless... 127

122(121).
  • Wings exhibiting a sharp bend in vein 4 ... 123
  • Wings without a sharp bend in vein 4... 124

123(122).
  • Hypopleural bristles present ... Tachinidae
  • Hypopleural bristles absent ... Muscidae

124(122).
  • Wing vein 6 reaching the wing margin ... 125
  • Wing vein 6 falling short of the wing margin... 126

125(124).
  • Antennae 1 segmented ... Hippoboscidae
  • Antennae 2 segmented ... Anthomyiidae
  • Antennae 3 segmented ... Anthomyiidae
  • Antennae 4 to 5 segmented ... Anthomyiidae
  • Antennae 6 to 7 segmented ... Anthomyiidae

126(124).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4 ... Muscidae
  • Wings without a sub-apical cell ... Fanniidae

127(121).
  • Antennae 1 segmented ... Hippoboscidae
  • Antennae 2 segmented ... Nycteribiidae

128(120).
  • Wings exhibiting a sharp bend in vein 4 ... 129
  • Wings without a sharp bend in vein 4... 131

129(128).
  • Hypopleural bristles present ... 130
  • Hypopleural bristles absent ... Muscidae

130(129).
  • Postscutellum present and well developed ... Tachinidae
  • Postscutellum absent or weakly developed ... Sarcophagidae

131(128).
  • Hypopleural bristles present ... Rhinophoridae
  • Hypopleural bristles absent... 132

132(131).
  • Wing vein 6 reaching the wing margin ... Anthomyiidae
  • Wing vein 6 falling short of the wing margin... 133

133(132).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4 ... Muscidae
  • Wings without a sub-apical cell ... Fanniidae

134(119).
  • winged ... 135
  • wingless... 145

135(134).
  • Wings exhibiting a sharp bend in vein 4 ... 136
  • Wings without a sharp bend in vein 4... 138

136(135).
  • Hypopleural bristles present ... 137
  • Hypopleural bristles absent ... Muscidae

137(136).
  • Postscutellum present and well developed ... Tachinidae
  • Postscutellum absent or weakly developed ... Calliphoridae

138(135).
  • Mouthparts adapted for piercing ... 139
  • Mouthparts non-piercing... 142

139(138).
  • Wing vein 6 reaching the wing margin ... 140
  • Wing vein 6 falling short of the wing margin... 141

140(139).
  • Antennae 1 segmented ... Hippoboscidae
  • Antennae 2 segmented ... Anthomyiidae
  • Antennae 3 segmented ... Anthomyiidae
  • Antennae 4 to 5 segmented ... Anthomyiidae
  • Antennae 6 to 7 segmented ... Anthomyiidae

141(139).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4 ... Muscidae
  • Wings without a sub-apical cell ... Fanniidae

142(138).
  • Hypopleural bristles present ... Rhinophoridae
  • Hypopleural bristles absent... 143

143(142).
  • Wing vein 6 reaching the wing margin ... Anthomyiidae
  • Wing vein 6 falling short of the wing margin... 144

144(143).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4 ... Muscidae
  • Wings without a sub-apical cell ... Fanniidae

145(134).
  • Antennae 1 segmented ... Hippoboscidae
  • Antennae 2 segmented ... Nycteribiidae

146(90).
  • Vibrissae present ... 147
  • Vibrissae absent... 166

147(146).
  • Ptilinal suture and lunule clearly defined ... 148
  • Ptilinal suture absent or weakly defined and the lunule often weakly defined or absent... 149

148(147).
  • Post-vertical orbital bristles convergent; tibiae with a dorsal pre-apical bristle ... Heleomyzidae
  • Post-vertical orbital bristles divergent; tibiae without a dorsal pre-apical bristle ... Piophilidae

149(147).
  • Antennae 1 segmented ... Phoridae
  • Antennae 2 segmented ... Xylomyidae
  • Antennae 3 segmented... 150
  • Antennae 4 to 5 segmented ... Xylomyidae
  • Antennae 6 to 7 segmented ... Xylomyidae
  • Antennae 8 to 10 segmented ... Thaumaleidae
  • Antennae 11 to 15 segmented... 165

150(149).
  • The costa extending around the entire wing ... 151
  • The costa not extending around the entire wing... 162

151(150).
  • Mouthparts adapted for piercing ... 152
  • Mouthparts non-piercing... 157

152(151).
  • Wings with the fourth posterior cell open ... 153
  • Wings with the fourth posterior cell closed... 155

153(152).
  • Antennae having the terminal segment annulated ... Xylophagidae
  • Antennae with a non-annulated terminal segment... 154

154(153).
  • Feet with a triple pad beneath the tarsal claws ... Rhagionidae
  • Feet without a triple pad ... Therevidae

155(152).
  • Feet with a triple pad beneath the tarsal claws ... 156
  • Feet without a triple pad ... Therevidae

156(155).
  • Antennae having the terminal segment annulated; not stilt-legged (legs of about average length and thickness) ... Xylomyidae
  • Antennae with a non-annulated terminal segment; stilt-legged (legs long and thin) ... Rhagionidae

157(151).
  • Wings with the fourth posterior cell open ... 158
  • Wings with the fourth posterior cell closed... 160

158(157).
  • Antennae having the terminal segment annulated; feet with a triple pad beneath the tarsal claws ... Xylophagidae
  • Antennae with a non-annulated terminal segment; feet without a triple pad... 159

159(158).
  • Wings with 7 cells between vein 3 and the anal cell; sub-costa joining vein 1 more or less where it joins the costa; life style of species parasitic; the larvae parasitic ... Bombyliidae
  • Wings with 8 cells between vein 3 and the anal cell; sub-costa reaching the costa independently of vein 1; life style of species non-parasitic; the larvae predatory ... Therevidae

160(157).
  • Antennae having the terminal segment annulated; feet with a triple pad beneath the tarsal claws ... Xylomyidae
  • Antennae with a non-annulated terminal segment; feet without a triple pad... 161

161(160).
  • Wings with 7 cells between vein 3 and the anal cell; sub-costa joining vein 1 more or less where it joins the costa; life style of species parasitic; the larvae parasitic ... Bombyliidae
  • Wings with 8 cells between vein 3 and the anal cell; sub-costa reaching the costa independently of vein 1; life style of species non-parasitic; the larvae predatory ... Therevidae

162(150).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4 ... 163
  • Wings without a sub-apical cell... 164

163(162).
  • Antennae aristate; wing vein 3 not forked; life style of species parasitic; the larvae acephalic; the pupae enclosed within a puparium ... Pipunculidae
  • Antennae not aristate; wing vein 3 distally forked; life style of species non-parasitic; the larvae hemicephalic; the pupae without a puparium ... Scenopinidae

164(162).
  • Wings with a discal cell; the pupae without a puparium ... Empididae
  • Wings without a discal cell; the pupae enclosed within a puparium ... Lonchopteridae

165(149).
  • Eyes asymmetric, nearly or quite connected above the antennae; not stilt-legged (legs of about average length and thickness); the costa extending around the entire wing ... Thaumaleidae
  • Eyes rounded, well separated; stilt-legged (legs long and thin); the costa not extending around the entire wing ... Chaoboridae

166(146).
  • Antennae having the terminal segment annulated ... 167
  • Antennae with a non-annulated terminal segment... 172

167(166).
  • The fork of wing vein 3 broad, its lower branch reaching the wing margin well below the apex ... 168
  • The fork of wing vein 3 narrow, its lower branch reaching the wing margin near the apex... 169

168(167).
  • Ocelli present; the costa not extending around the entire wing; tibiae without spurs ... Stratiomyidae
  • Ocelli absent; the costa extending around the entire wing; tibiae spurred ... Tabanidae

169(167).
  • Wings with the fourth posterior cell open ... 170
  • Wings with the fourth posterior cell closed... 171

170(169).
  • The costa extending around the entire wing ... Xylophagidae
  • The costa not extending around the entire wing ... Stratiomyidae

171(169).
  • The costa extending around the entire wing ... Xylomyidae
  • The costa not extending around the entire wing ... Stratiomyidae

172(166).
  • Antennae 1 segmented ... Phoridae
  • Antennae 2 segmented ... Acroceridae
  • Antennae 3 segmented... 173
  • Antennae 8 to 10 segmented ... Thaumaleidae
  • Antennae 11 to 15 segmented... 187

173(172).
  • The costa extending around the entire wing ... 174
  • The costa not extending around the entire wing... 182

174(173).
  • Mouthparts adapted for piercing ... 175
  • Mouthparts non-piercing... 180

175(174).
  • The top of the head with a marked depression between the eyes, within which the ocellar triangle projects ... 176
  • The top of the head with no marked depression between the eyes... 178

176(175).
  • Feet with a triple pad beneath the tarsal claws ... 177
  • Feet without a triple pad ... Asilidae

177(176).
  • The larvae saprophagous ... Athericidae
  • The larvae predatory ... Rhagionidae

178(175).
  • Feet with a triple pad beneath the tarsal claws ... 179
  • Feet without a triple pad ... Therevidae

179(178).
  • The larvae saprophagous ... Athericidae
  • The larvae predatory ... Rhagionidae

180(174).
  • Feet with a triple pad beneath the tarsal claws; the larvae aquatic ... Athericidae
  • Feet without a triple pad; the larvae terrestrial... 181

181(180).
  • Sub-costa reaching the costa independently of vein 1; wings with 8 cells between vein 3 and the anal cell; life style of species non-parasitic; the larvae predatory ... Therevidae
  • Sub-costa joining vein 1 more or less where it joins the costa; wings with 7 cells between vein 3 and the anal cell; life style of species parasitic; the larvae parasitic ... Bombyliidae

182(173).
  • Wings with a discal cell ... 183
  • Wings without a discal cell... 185

183(182).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4 ... 184
  • Wings without a sub-apical cell ... Empididae

184(183).
  • Antennae aristate; wing vein 3 not forked; life style of species parasitic; the larvae acephalic; the pupae enclosed within a puparium ... Pipunculidae
  • Antennae not aristate; wing vein 3 distally forked; life style of species non-parasitic; the larvae hemicephalic; the pupae without a puparium ... Scenopinidae

185(182).
  • Eyes asymmetric, nearly or quite connected above the antennae; mouthparts of adults non-functional; the leading edge veins markedly stronger than the rest; life style of species parasitic ... Acroceridae
  • Eyes rounded, well separated; mouthparts of adults functional; the leading edge veins not noticeably stronger than the rest; life style of species non-parasitic... 186

186(185).
  • Wings with a closed anal cell; the pupae without a puparium ... Dolichopodidae
  • Wings without a closed anal cell; the pupae enclosed within a puparium ... Lonchopteridae

187(172).
  • Eyes asymmetric, nearly or quite connected above the antennae; not stilt-legged (legs of about average length and thickness); the costa extending around the entire wing ... Thaumaleidae
  • Eyes rounded, well separated; stilt-legged (legs long and thin); the costa not extending around the entire wing ... Chaoboridae

188(89).
  • Vibrissae present ... 189
  • Vibrissae absent... 369

189(188).
  • Ptilinal suture and lunule clearly defined ... 190
  • Ptilinal suture absent or weakly defined and the lunule often weakly defined or absent... 352

190(189).
  • The third antennal segment elongated ... 191
  • The third antennal segment not elongated... 219

191(190).
  • Thorax with the dorsal suture just in front of the wing bases continuous across the middle; thorax with well defined posterior calli ... 192
  • Thorax without a continuous dorsal suture; thorax without well defined posterior calli... 193

192(191).
  • Mouthparts of adults functional ... Rhinophoridae
  • Mouthparts of adults non-functional ... Oestridae

193(191).
  • Post-vertical orbital bristles present ... 194
  • Post-vertical orbital bristles absent... 212

194(193).
  • Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells ... 195
  • Wing venation incomplete, in the sense of lacking one or more of the cells... 204

195(194).
  • Wing vein 6 present ... 196
  • Wing vein 6 absent... 203

196(195).
  • Wing vein 6 reaching the wing margin ... 197
  • Wing vein 6 falling short of the wing margin... 200

197(196).
  • The anal cell extending more than halfway to the wing margin; life style of species parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; life style of species non-parasitic... 198

198(197).
  • The costa unbroken ... 199
  • The costa with one break ... Heleomyzidae
  • The costa with two breaks ... Campichoetidae

199(198).
  • Post-vertical orbital bristles convergent ... Heleomyzidae
  • Post-vertical orbital bristles parallel ... Dryomyzidae
  • Post-vertical orbital bristles divergent ... Dryomyzidae

200(196).
  • Post-vertical orbital bristles convergent ... 201
  • Post-vertical orbital bristles parallel ... Campichoetidae
  • Post-vertical orbital bristles divergent... 202

201(200).
  • Tibiae with a dorsal pre-apical bristle; the costa with two breaks ... Campichoetidae
  • Tibiae without a dorsal pre-apical bristle; the costa with one break ... Tethinidae

202(200).
  • The costa unbroken ... Sepsidae
  • The costa with one break ... LonchaeidaeCanacidae
  • The costa with two breaks ... Campichoetidae

203(195).
  • Tibiae with a dorsal pre-apical bristle ... Campichoetidae
  • Tibiae without a dorsal pre-apical bristle ... Milichiidae

204(194).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 205
  • Wing vein 4 extending far beyond the end of the first basal cell... 208

205(204).
  • Wings with a closed anal cell ... 206
  • Wings without a closed anal cell... 207

206(205).
  • The anal cell extending more than halfway to the wing margin; the costa unbroken; life style of species parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; the costa with two breaks; life style of species non-parasitic ... Campichoetidae

207(205).
  • Sub-costa apparent and at least partially free of vein 1; life style of species parasitic ... Carnidae
  • Sub-costa absent or only dubiously identifiable; life style of species non-parasitic ... Camillidae

208(204).
  • Wings with a closed anal cell ... 209
  • Wings without a closed anal cell... 211

209(208).
  • The anal cell extending more than halfway to the wing margin; life style of species parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; life style of species non-parasitic... 210

210(209).
  • The costa unbroken ... Sepsidae
  • The costa with two breaks ... Campichoetidae

211(208).
  • Post-vertical orbital bristles convergent; sub-costa absent or only dubiously identifiable; the costa with two breaks ... Camillidae
  • Post-vertical orbital bristles divergent; sub-costa apparent and at least partially free of vein 1; the costa unbroken ... Asteiidae

212(193).
  • winged ... 213
  • wingless ... Braulidae

213(212).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 214
  • Wing vein 4 extending far beyond the end of the first basal cell... 216

214(213).
  • Wings with a closed anal cell ... 215
  • Wings without a closed anal cell ... Carnidae

215(214).
  • The anal cell extending more than halfway to the wing margin; the costa unbroken; life style of species parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; the costa with two breaks; life style of species non-parasitic ... Campichoetidae

216(213).
  • Wings with a closed anal cell ... 217
  • Wings without a closed anal cell ... Ephydridae

217(216).
  • The anal cell extending more than halfway to the wing margin; life style of species parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; life style of species non-parasitic... 218

218(217).
  • The costa with one break ... Aulacigastridae
  • The costa with two breaks ... Campichoetidae

219(190).
  • The front femora with a short stout spine beneath which is readily distinguishable from the other bristles ... 220
  • The front femora without a conspicuous spine beneath... 288

220(219).
  • The legs with brown and yellow bands ... 221
  • The legs without brown and yellow bands... 258

221(220).
  • Thorax with the dorsal suture just in front of the wing bases continuous across the middle; thorax with well defined posterior calli ... 222
  • Thorax without a continuous dorsal suture; thorax without well defined posterior calli... 223

222(221).
  • Mouthparts of adults functional ... Rhinophoridae
  • Mouthparts of adults non-functional ... Oestridae

223(221).
  • Post-vertical orbital bristles present ... 224
  • Post-vertical orbital bristles absent... 251

224(223).
  • Antennal arista characteristically, conspicuously forked at the tip ... Drosophilidae
  • Antennal arista not forked at the tip... 225

225(224).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 226
  • Wing vein 4 extending far beyond the end of the first basal cell... 236

226(225).
  • Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells ... 227
  • Wing venation incomplete, in the sense of lacking one or more of the cells... 233

227(226).
  • Wings with a closed anal cell ... 228
  • Wings without a closed anal cell ... Diastatidae

228(227).
  • Wing vein 6 reaching the wing margin ... 229
  • Wing vein 6 falling short of the wing margin... 232

229(228).
  • Wing vein 6 present ... 230
  • Wing vein 6 absent ... Milichiidae

230(229).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4; the anal cell extending more than halfway to the wing margin; life style of species parasitic ... Conopidae
  • Wings without a sub-apical cell; the anal cell extending less than halfway to the wing margin; life style of species non-parasitic... 231

231(230).
  • Post-vertical orbital bristles convergent ... Heleomyzidae
  • Post-vertical orbital bristles parallel ... Dryomyzidae
  • Post-vertical orbital bristles divergent ... Dryomyzidae

232(228).
  • Wing vein 6 present ... TethinidaeAnthomyzidae
  • Wing vein 6 absent ... Milichiidae

233(226).
  • Sub-costa apparent and at least partially free of vein 1 ... 234
  • Sub-costa absent or only dubiously identifiable ... Camillidae

234(233).
  • Wings with a discal cell; wings with a closed anal cell ... 235
  • Wings without a discal cell; wings without a closed anal cell ... Carnidae

235(234).
  • The anal cell extending more than halfway to the wing margin; wing vein 6 reaching the wing margin; life style of species parasitic; the larvae parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; wing vein 6 falling short of the wing margin; life style of species non-parasitic; the larvae phytophagous ... Anthomyzidae

236(225).
  • Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells ... 237
  • Wing venation incomplete, in the sense of lacking one or more of the cells... 247

237(236).
  • Wings with a closed anal cell ... 238
  • Wings without a closed anal cell ... Diastatidae

238(237).
  • Tibiae with a dorsal pre-apical bristle ... 239
  • Tibiae without a dorsal pre-apical bristle... 243

239(238).
  • Wing vein 6 reaching the wing margin ... 240
  • Wing vein 6 falling short of the wing margin... 242

240(239).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4; the anal cell extending more than halfway to the wing margin; life style of species parasitic ... Conopidae
  • Wings without a sub-apical cell; the anal cell extending less than halfway to the wing margin; life style of species non-parasitic... 241

241(240).
  • Post-vertical orbital bristles convergent ... Heleomyzidae
  • Post-vertical orbital bristles parallel ... Dryomyzidae
  • Post-vertical orbital bristles divergent ... Dryomyzidae

242(239).
  • Adults less than 4 mm long; the costa with one break ... Odiniidae
  • Adults 4-8 mm long; the costa unbroken ... Sepsidae

243(238).
  • Adults less than 4 mm long ... 244
  • Adults 4-8 mm long... 245
  • Adults 8-15 mm long ... Conopidae
  • Adults 15 mm or more long ... Conopidae

244(243).
  • Wing vein 6 present ... TethinidaeAnthomyzidae
  • Wing vein 6 absent ... Milichiidae

245(243).
  • Wing vein 6 present ... 246
  • Wing vein 6 absent ... Milichiidae

246(245).
  • The costa unbroken ... Sepsidae
  • The costa with one break ... Piophilidae

247(236).
  • Wings with a discal cell; wings with a closed anal cell ... 248
  • Wings without a discal cell; wings without a closed anal cell... 250

248(247).
  • Adults less than 4 mm long ... 249
  • Adults 4-8 mm long ... Sepsidae
  • Adults 8-15 mm long ... Conopidae
  • Adults 15 mm or more long ... Conopidae

249(248).
  • Tibiae with a dorsal pre-apical bristle; the larvae mycophagous ... Odiniidae
  • Tibiae without a dorsal pre-apical bristle; the larvae phytophagous ... Anthomyzidae

250(247).
  • Post-vertical orbital bristles convergent; sub-costa absent or only dubiously identifiable; the costa with two breaks ... Camillidae
  • Post-vertical orbital bristles divergent; sub-costa apparent and at least partially free of vein 1; the costa unbroken ... Asteiidae

251(223).
  • winged ... 252
  • wingless ... Braulidae

252(251).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 253
  • Wing vein 4 extending far beyond the end of the first basal cell... 255

253(252).
  • Wings with a discal cell; wings with a closed anal cell ... 254
  • Wings without a discal cell; wings without a closed anal cell ... Carnidae

254(253).
  • The anal cell extending more than halfway to the wing margin; wing vein 6 reaching the wing margin; life style of species parasitic; the larvae parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; wing vein 6 falling short of the wing margin; life style of species non-parasitic; the larvae phytophagous ... Anthomyzidae

255(252).
  • Wings with a discal cell ... 256
  • Wings without a discal cell... 257

256(255).
  • The anal cell extending more than halfway to the wing margin; wing vein 6 reaching the wing margin; life style of species parasitic; the larvae parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; wing vein 6 falling short of the wing margin; life style of species non-parasitic; the larvae phytophagous ... Anthomyzidae

257(255).
  • Wings with a closed anal cell; the costa with one break ... Aulacigastridae
  • Wings without a closed anal cell; the costa with two breaks ... Ephydridae

258(220).
  • Thorax with the dorsal suture just in front of the wing bases continuous across the middle; thorax with well defined posterior calli ... 259
  • Thorax without a continuous dorsal suture; thorax without well defined posterior calli... 260

259(258).
  • Mouthparts of adults functional ... Rhinophoridae
  • Mouthparts of adults non-functional ... Oestridae

260(258).
  • Post-vertical orbital bristles present ... 261
  • Post-vertical orbital bristles absent... 281

261(260).
  • Antennal arista characteristically, conspicuously forked at the tip ... Drosophilidae
  • Antennal arista not forked at the tip... 262

262(261).
  • Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells ... 263
  • Wing venation incomplete, in the sense of lacking one or more of the cells... 274

263(262).
  • Wings with a closed anal cell ... 264
  • Wings without a closed anal cell ... Diastatidae

264(263).
  • Wing vein 6 present ... 265
  • Wing vein 6 absent ... Milichiidae

265(264).
  • Wing vein 6 reaching the wing margin ... 266
  • Wing vein 6 falling short of the wing margin... 269

266(265).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4; the anal cell extending more than halfway to the wing margin ... Conopidae
  • Wings without a sub-apical cell; the anal cell extending less than halfway to the wing margin... 267

267(266).
  • Tibiae with a dorsal pre-apical bristle ... 268
  • Tibiae without a dorsal pre-apical bristle ... Piophilidae

268(267).
  • Post-vertical orbital bristles convergent ... Heleomyzidae
  • Post-vertical orbital bristles parallel ... Dryomyzidae
  • Post-vertical orbital bristles divergent ... Dryomyzidae

269(265).
  • Post-vertical orbital bristles convergent ... TethinidaeAnthomyzidae
  • Post-vertical orbital bristles parallel ... Anthomyzidae
  • Post-vertical orbital bristles divergent... 270

270(269).
  • Tibiae with a dorsal pre-apical bristle ... 271
  • Tibiae without a dorsal pre-apical bristle... 272

271(270).
  • The costa unbroken ... Sepsidae
  • The costa with one break ... Canacidae

272(270).
  • Adults less than 4 mm long ... Anthomyzidae
  • Adults 4-8 mm long... 273

273(272).
  • The costa unbroken ... Sepsidae
  • The costa with one break ... Piophilidae

274(262).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 275
  • Wing vein 4 extending far beyond the end of the first basal cell... 278

275(274).
  • Sub-costa apparent and at least partially free of vein 1 ... 276
  • Sub-costa absent or only dubiously identifiable ... Camillidae

276(275).
  • Wings with a discal cell; wings with a closed anal cell ... 277
  • Wings without a discal cell; wings without a closed anal cell ... Carnidae

277(276).
  • The anal cell extending more than halfway to the wing margin; wing vein 6 reaching the wing margin; life style of species parasitic; the larvae parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; wing vein 6 falling short of the wing margin; life style of species non-parasitic; the larvae phytophagous ... Anthomyzidae

278(274).
  • Wings with a discal cell; wings with a closed anal cell ... 279
  • Wings without a discal cell; wings without a closed anal cell... 280

279(278).
  • Adults less than 4 mm long ... Anthomyzidae
  • Adults 4-8 mm long ... Sepsidae
  • Adults 8-15 mm long ... Conopidae
  • Adults 15 mm or more long ... Conopidae

280(278).
  • Post-vertical orbital bristles convergent; sub-costa absent or only dubiously identifiable; the costa with two breaks ... Camillidae
  • Post-vertical orbital bristles divergent; sub-costa apparent and at least partially free of vein 1; the costa unbroken ... Asteiidae

281(260).
  • winged ... 282
  • wingless ... Braulidae

282(281).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 283
  • Wing vein 4 extending far beyond the end of the first basal cell... 285

283(282).
  • Wings with a discal cell; wings with a closed anal cell ... 284
  • Wings without a discal cell; wings without a closed anal cell ... Carnidae

284(283).
  • The anal cell extending more than halfway to the wing margin; wing vein 6 reaching the wing margin; life style of species parasitic; the larvae parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; wing vein 6 falling short of the wing margin; life style of species non-parasitic; the larvae phytophagous ... Anthomyzidae

285(282).
  • Wings with a discal cell ... 286
  • Wings without a discal cell... 287

286(285).
  • The anal cell extending more than halfway to the wing margin; wing vein 6 reaching the wing margin; life style of species parasitic; the larvae parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; wing vein 6 falling short of the wing margin; life style of species non-parasitic; the larvae phytophagous ... Anthomyzidae

287(285).
  • Wings with a closed anal cell; the costa with one break ... Aulacigastridae
  • Wings without a closed anal cell; the costa with two breaks ... Ephydridae

288(219).
  • The legs with brown and yellow bands ... 289
  • The legs without brown and yellow bands... 324

289(288).
  • Thorax with the dorsal suture just in front of the wing bases continuous across the middle; thorax with well defined posterior calli ... 290
  • Thorax without a continuous dorsal suture; thorax without well defined posterior calli... 291

290(289).
  • Mouthparts of adults functional ... Rhinophoridae
  • Mouthparts of adults non-functional ... Oestridae

291(289).
  • Tibiae with a dorsal pre-apical bristle ... 292
  • Tibiae without a dorsal pre-apical bristle... 301

292(291).
  • Post-vertical orbital bristles present ... 293
  • Post-vertical orbital bristles absent... 299

293(292).
  • Antennal arista characteristically, conspicuously forked at the tip ... Drosophilidae
  • Antennal arista not forked at the tip... 294

294(293).
  • Sub-costa reaching the costa independently of vein 1 ... 295
  • Sub-costa joining vein 1 more or less where it joins the costa ... Odiniidae
  • Sub-costa joining vein 1 well short of the costa ... Diastatidae
  • Sub-costa terminating blind... 298

295(294).
  • Wing vein 6 reaching the wing margin ... 296
  • Wing vein 6 falling short of the wing margin ... Sepsidae

296(295).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4; the anal cell extending more than halfway to the wing margin; life style of species parasitic ... Conopidae
  • Wings without a sub-apical cell; the anal cell extending less than halfway to the wing margin; life style of species non-parasitic... 297

297(296).
  • Post-vertical orbital bristles convergent ... Heleomyzidae
  • Post-vertical orbital bristles parallel ... Dryomyzidae
  • Post-vertical orbital bristles divergent ... Dryomyzidae

298(294).
  • Post-vertical orbital bristles convergent; wing vein 6 reaching the wing margin ... Heleomyzidae
  • Post-vertical orbital bristles divergent; wing vein 6 falling short of the wing margin ... Odiniidae

299(292).
  • winged ... 300
  • wingless ... Braulidae

300(299).
  • Wings with a discal cell; the anal cell extending more than halfway to the wing margin; the costa unbroken; life style of species parasitic; the larvae parasitic ... Conopidae
  • Wings without a discal cell; the anal cell extending less than halfway to the wing margin; the costa with one break; life style of species non-parasitic; the larvae saprophagous ... Aulacigastridae

301(291).
  • Post-vertical orbital bristles present ... 302
  • Post-vertical orbital bristles absent... 319

302(301).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 303
  • Wing vein 4 extending far beyond the end of the first basal cell... 308

303(302).
  • Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells ... 304
  • Wing venation incomplete, in the sense of lacking one or more of the cells... 306

304(303).
  • Wing vein 6 present ... 305
  • Wing vein 6 absent ... Milichiidae

305(304).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4; the anal cell extending more than halfway to the wing margin; wing vein 6 reaching the wing margin; the costa unbroken; life style of species parasitic ... Conopidae
  • Wings without a sub-apical cell; the anal cell extending less than halfway to the wing margin; wing vein 6 falling short of the wing margin; the costa with one break; life style of species non-parasitic ... Tethinidae

306(303).
  • Sub-costa apparent and at least partially free of vein 1; life style of species parasitic ... 307
  • Sub-costa absent or only dubiously identifiable; life style of species non-parasitic ... Camillidae

307(306).
  • Wings with a discal cell; wings with a more or less closed subapical cell bounded by veins 3 and 4; wings with a closed anal cell; wing vein 6 reaching the wing margin; the costa unbroken ... Conopidae
  • Wings without a discal cell; wings without a sub-apical cell; wings without a closed anal cell; wing vein 6 falling short of the wing margin; the costa with two breaks ... Carnidae

308(302).
  • Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells ... 309
  • Wing venation incomplete, in the sense of lacking one or more of the cells... 315

309(308).
  • Wing vein 6 present ... 310
  • Wing vein 6 absent ... Milichiidae

310(309).
  • Sub-costa reaching the costa independently of vein 1 ... 311
  • Sub-costa joining vein 1 more or less where it joins the costa ... Tethinidae
  • Sub-costa joining vein 1 well short of the costa... 313
  • Sub-costa terminating blind... 314

311(310).
  • The anal cell extending more than halfway to the wing margin ... Conopidae
  • The anal cell extending less than halfway to the wing margin... 312

312(311).
  • The costa unbroken ... Sepsidae
  • The costa with one break ... Piophilidae

313(310).
  • Post-vertical orbital bristles convergent ... Tethinidae
  • Post-vertical orbital bristles divergent ... Agromyzidae

314(310).
  • Post-vertical orbital bristles convergent ... Tethinidae
  • Post-vertical orbital bristles divergent ... Agromyzidae

315(308).
  • Wings with a closed anal cell ... 316
  • Wings without a closed anal cell... 318

316(315).
  • Sub-costa reaching the costa independently of vein 1 ... 317
  • Sub-costa joining vein 1 well short of the costa ... Agromyzidae
  • Sub-costa terminating blind ... Agromyzidae

317(316).
  • The anal cell extending more than halfway to the wing margin; wing vein 6 reaching the wing margin; life style of species parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; wing vein 6 falling short of the wing margin; life style of species non-parasitic ... Sepsidae

318(315).
  • Post-vertical orbital bristles convergent; sub-costa absent or only dubiously identifiable; the costa with two breaks ... Camillidae
  • Post-vertical orbital bristles divergent; sub-costa apparent and at least partially free of vein 1; the costa unbroken ... Asteiidae

319(301).
  • winged ... 320
  • wingless ... Braulidae

320(319).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 321
  • Wing vein 4 extending far beyond the end of the first basal cell... 322

321(320).
  • Wings with a discal cell; wings with a more or less closed subapical cell bounded by veins 3 and 4; wings with a closed anal cell; wing vein 6 reaching the wing margin; the costa unbroken ... Conopidae
  • Wings without a discal cell; wings without a sub-apical cell; wings without a closed anal cell; wing vein 6 falling short of the wing margin; the costa with two breaks ... Carnidae

322(320).
  • Wings with a closed anal cell ... 323
  • Wings without a closed anal cell ... Ephydridae

323(322).
  • Wings with a discal cell; the anal cell extending more than halfway to the wing margin; the costa unbroken; life style of species parasitic; the larvae parasitic ... Conopidae
  • Wings without a discal cell; the anal cell extending less than halfway to the wing margin; the costa with one break; life style of species non-parasitic; the larvae saprophagous ... Aulacigastridae

324(288).
  • Thorax with the dorsal suture just in front of the wing bases continuous across the middle; thorax with well defined posterior calli ... 325
  • Thorax without a continuous dorsal suture; thorax without well defined posterior calli... 326

325(324).
  • Mouthparts of adults functional ... Rhinophoridae
  • Mouthparts of adults non-functional ... Oestridae

326(324).
  • Post-vertical orbital bristles present ... 327
  • Post-vertical orbital bristles absent... 347

327(326).
  • Antennal arista characteristically, conspicuously forked at the tip ... Drosophilidae
  • Antennal arista not forked at the tip... 328

328(327).
  • Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells ... 329
  • Wing venation incomplete, in the sense of lacking one or more of the cells... 340

329(328).
  • Wings with a closed anal cell ... 330
  • Wings without a closed anal cell ... Diastatidae

330(329).
  • Wing vein 6 present ... 331
  • Wing vein 6 absent ... Milichiidae

331(330).
  • Wing vein 6 reaching the wing margin ... 332
  • Wing vein 6 falling short of the wing margin... 335

332(331).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4; the anal cell extending more than halfway to the wing margin ... Conopidae
  • Wings without a sub-apical cell; the anal cell extending less than halfway to the wing margin... 333

333(332).
  • Tibiae with a dorsal pre-apical bristle ... 334
  • Tibiae without a dorsal pre-apical bristle ... Piophilidae

334(333).
  • Post-vertical orbital bristles convergent ... Heleomyzidae
  • Post-vertical orbital bristles parallel ... Dryomyzidae
  • Post-vertical orbital bristles divergent ... Dryomyzidae

335(331).
  • Post-vertical orbital bristles convergent ... Tethinidae
  • Post-vertical orbital bristles divergent... 336

336(335).
  • Tibiae with a dorsal pre-apical bristle ... 337
  • Tibiae without a dorsal pre-apical bristle... 338

337(336).
  • The costa unbroken ... Sepsidae
  • The costa with one break ... Canacidae

338(336).
  • Sub-costa reaching the costa independently of vein 1 ... 339
  • Sub-costa joining vein 1 well short of the costa ... Agromyzidae
  • Sub-costa terminating blind ... Agromyzidae

339(338).
  • The costa unbroken ... Sepsidae
  • The costa with one break ... Piophilidae

340(328).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 341
  • Wing vein 4 extending far beyond the end of the first basal cell... 343

341(340).
  • Sub-costa apparent and at least partially free of vein 1; life style of species parasitic ... 342
  • Sub-costa absent or only dubiously identifiable; life style of species non-parasitic ... Camillidae

342(341).
  • Wings with a discal cell; wings with a more or less closed subapical cell bounded by veins 3 and 4; wings with a closed anal cell; wing vein 6 reaching the wing margin; the costa unbroken ... Conopidae
  • Wings without a discal cell; wings without a sub-apical cell; wings without a closed anal cell; wing vein 6 falling short of the wing margin; the costa with two breaks ... Carnidae

343(340).
  • Wings with a closed anal cell ... 344
  • Wings without a closed anal cell... 346

344(343).
  • Sub-costa reaching the costa independently of vein 1 ... 345
  • Sub-costa joining vein 1 well short of the costa ... Agromyzidae
  • Sub-costa terminating blind ... Agromyzidae

345(344).
  • The anal cell extending more than halfway to the wing margin; wing vein 6 reaching the wing margin; life style of species parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; wing vein 6 falling short of the wing margin; life style of species non-parasitic ... Sepsidae

346(343).
  • Post-vertical orbital bristles convergent; sub-costa absent or only dubiously identifiable; the costa with two breaks ... Camillidae
  • Post-vertical orbital bristles divergent; sub-costa apparent and at least partially free of vein 1; the costa unbroken ... Asteiidae

347(326).
  • winged ... 348
  • wingless ... Braulidae

348(347).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 349
  • Wing vein 4 extending far beyond the end of the first basal cell... 350

349(348).
  • Wings with a discal cell; wings with a more or less closed subapical cell bounded by veins 3 and 4; wings with a closed anal cell; wing vein 6 reaching the wing margin; the costa unbroken ... Conopidae
  • Wings without a discal cell; wings without a sub-apical cell; wings without a closed anal cell; wing vein 6 falling short of the wing margin; the costa with two breaks ... Carnidae

350(348).
  • Wings with a closed anal cell ... 351
  • Wings without a closed anal cell ... Ephydridae

351(350).
  • Wings with a discal cell; the anal cell extending more than halfway to the wing margin; the costa unbroken; life style of species parasitic; the larvae parasitic ... Conopidae
  • Wings without a discal cell; the anal cell extending less than halfway to the wing margin; the costa with one break; life style of species non-parasitic; the larvae saprophagous ... Aulacigastridae

352(189).
  • Antennae 1 segmented ... Phoridae
  • Antennae 2 segmented ... Xylomyidae
  • Antennae 3 segmented... 353
  • Antennae 4 to 5 segmented ... Xylomyidae
  • Antennae 6 to 7 segmented ... Xylomyidae
  • Antennae 8 to 10 segmented ... Thaumaleidae
  • Antennae 11 to 15 segmented... 368

353(352).
  • The costa extending around the entire wing ... 354
  • The costa not extending around the entire wing... 365

354(353).
  • Mouthparts adapted for piercing ... 355
  • Mouthparts non-piercing... 360

355(354).
  • Wings with the fourth posterior cell open ... 356
  • Wings with the fourth posterior cell closed... 358

356(355).
  • Antennae having the terminal segment annulated ... Xylophagidae
  • Antennae with a non-annulated terminal segment... 357

357(356).
  • Feet with a triple pad beneath the tarsal claws ... Rhagionidae
  • Feet without a triple pad ... Therevidae

358(355).
  • Feet with a triple pad beneath the tarsal claws ... 359
  • Feet without a triple pad ... Therevidae

359(358).
  • Antennae having the terminal segment annulated; not stilt-legged (legs of about average length and thickness) ... Xylomyidae
  • Antennae with a non-annulated terminal segment; stilt-legged (legs long and thin) ... Rhagionidae

360(354).
  • Wings with the fourth posterior cell open ... 361
  • Wings with the fourth posterior cell closed... 363

361(360).
  • Antennae having the terminal segment annulated; feet with a triple pad beneath the tarsal claws ... Xylophagidae
  • Antennae with a non-annulated terminal segment; feet without a triple pad... 362

362(361).
  • Wings with 7 cells between vein 3 and the anal cell; sub-costa joining vein 1 more or less where it joins the costa; life style of species parasitic; the larvae parasitic ... Bombyliidae
  • Wings with 8 cells between vein 3 and the anal cell; sub-costa reaching the costa independently of vein 1; life style of species non-parasitic; the larvae predatory ... Therevidae

363(360).
  • Antennae having the terminal segment annulated; feet with a triple pad beneath the tarsal claws ... Xylomyidae
  • Antennae with a non-annulated terminal segment; feet without a triple pad... 364

364(363).
  • Wings with 7 cells between vein 3 and the anal cell; sub-costa joining vein 1 more or less where it joins the costa; life style of species parasitic; the larvae parasitic ... Bombyliidae
  • Wings with 8 cells between vein 3 and the anal cell; sub-costa reaching the costa independently of vein 1; life style of species non-parasitic; the larvae predatory ... Therevidae

365(353).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4 ... 366
  • Wings without a sub-apical cell... 367

366(365).
  • Antennae aristate; wing vein 3 not forked; life style of species parasitic; the larvae acephalic; the pupae enclosed within a puparium ... Pipunculidae
  • Antennae not aristate; wing vein 3 distally forked; life style of species non-parasitic; the larvae hemicephalic; the pupae without a puparium ... Scenopinidae

367(365).
  • Wings with a discal cell; the pupae without a puparium ... Empididae
  • Wings without a discal cell; the pupae enclosed within a puparium ... Lonchopteridae

368(352).
  • stilt-legged (legs long and thin); eyes rounded, well separated; the costa not extending around the entire wing ... Chaoboridae
  • not stilt-legged (legs of about average length and thickness); eyes asymmetric, nearly or quite connected above the antennae; the costa extending around the entire wing ... Thaumaleidae

369(188).
  • Ptilinal suture and lunule clearly defined ... 370
  • Ptilinal suture absent or weakly defined and the lunule often weakly defined or absent... 504

370(369).
  • stilt-legged (legs long and thin) ... 371
  • not stilt-legged (legs of about average length and thickness)... 374

371(370).
  • Sub-costa reaching the costa independently of vein 1; wings with a closed anal cell ... 372
  • Sub-costa joining vein 1 more or less where it joins the costa; wings without a closed anal cell ... Stenomicridae

372(371).
  • The hind femora thickened, with two rows of spines beneath ... Megamerinidae
  • The hind femora not thickened with spines beneath as in Megamerinidae... 373

373(372).
  • The costa unbroken ... Micropezidae
  • The costa with one break ... Tanypezidae

374(370).
  • The third antennal segment elongated ... 375
  • The third antennal segment not elongated... 459

375(374).
  • The legs with brown and yellow bands ... 376
  • The legs without brown and yellow bands... 419

376(375).
  • Thorax with the dorsal suture just in front of the wing bases continuous across the middle; thorax with well defined posterior calli ... 377
  • Thorax without a continuous dorsal suture; thorax without well defined posterior calli... 378

377(376).
  • Mouthparts of adults functional ... Rhinophoridae
  • Mouthparts of adults non-functional ... Oestridae

378(376).
  • Tibiae with a dorsal pre-apical bristle ... 379
  • Tibiae without a dorsal pre-apical bristle... 389

379(378).
  • winged ... 380
  • wingless ... Braulidae

380(379).
  • Wing vein 6 reaching the wing margin ... 381
  • Wing vein 6 falling short of the wing margin... 384

381(380).
  • The anal cell extending more than halfway to the wing margin ... Conopidae
  • The anal cell extending less than halfway to the wing margin... 382

382(381).
  • Life style of species parasitic ... 383
  • Life style of species non-parasitic ... Dryomyzidae

383(382).
  • On slugs and snails ... Sciomyzidae
  • On millipedes ... Phaeomyiidae

384(380).
  • Post-vertical orbital bristles convergent ... Lauxaniidae
  • Post-vertical orbital bristles parallel ... Phaeomyiidae
  • Post-vertical orbital bristles divergent... 385

385(384).
  • Adults less than 4 mm long ... Acartophthalmidae
  • Adults 4-8 mm long... 386

386(385).
  • shining, black, rather hairy flies ... 387
  • not shining black... 388

387(386).
  • The costa unbroken ... Sepsidae
  • The costa with one break ... Lonchaeidae

388(386).
  • Life style of species parasitic ... Phaeomyiidae
  • Life style of species non-parasitic ... Sepsidae

389(378).
  • Adults less than 4 mm long ... 390
  • Adults 4-8 mm long... 401
  • Adults 8-15 mm long... 416
  • Adults 15 mm or more long... 418

390(389).
  • winged ... 391
  • wingless ... Braulidae

391(390).
  • Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells ... 392
  • Wing venation incomplete, in the sense of lacking one or more of the cells... 395

392(391).
  • Wings with a closed anal cell ... 393
  • Wings without a closed anal cell ... Periscelididae

393(392).
  • Wing vein 6 present ... 394
  • Wing vein 6 absent ... Milichiidae

394(393).
  • The costa unbroken ... Chamaemyiidae
  • The costa with one break ... Acartophthalmidae

395(391).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 396
  • Wing vein 4 extending far beyond the end of the first basal cell... 397

396(395).
  • The costa unbroken ... Periscelididae
  • The costa with one break ... Chloropidae
  • The costa with two breaks ... Carnidae

397(395).
  • Post-vertical orbital bristles present ... 398
  • Post-vertical orbital bristles absent... 400

398(397).
  • The costa unbroken ... 399
  • The costa with one break ... Chloropidae

399(398).
  • Sub-costa joining vein 1 well short of the costa ... Asteiidae
  • Sub-costa terminating blind ... Periscelididae

400(397).
  • The costa with one break ... Chloropidae
  • The costa with two breaks ... Ephydridae

401(389).
  • Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells ... 402
  • Wing venation incomplete, in the sense of lacking one or more of the cells... 414

402(401).
  • Wing vein 1 with hairs on its upper side ... 403
  • Wing vein 1 bare... 406

403(402).
  • Wings patterned ... Platystomatidae
  • Wings unpatterned... 404

404(403).
  • Wing vein 6 present ... 405
  • Wing vein 6 absent ... Milichiidae

405(404).
  • Sub-costa reaching the costa independently of vein 1; the costa unbroken ... Sepsidae
  • Sub-costa terminating blind; the costa with one break ... Psilidae

406(402).
  • Sub-costa reaching the costa independently of vein 1 ... 407
  • Sub-costa joining vein 1 more or less where it joins the costa ... Milichiidae
  • Sub-costa joining vein 1 well short of the costa ... Milichiidae
  • Sub-costa terminating blind... 412

407(406).
  • shining, black, rather hairy flies ... 408
  • not shining black... 409

408(407).
  • The costa unbroken ... Sepsidae
  • The costa with one break ... Lonchaeidae

409(407).
  • Post-vertical orbital bristles present ... 410
  • Post-vertical orbital bristles absent ... Opomyzidae

410(409).
  • Wings patterned ... Pallopteridae
  • Wings unpatterned... 411

411(410).
  • Post-vertical orbital bristles convergent ... Chyromyidae
  • Post-vertical orbital bristles divergent ... Sepsidae

412(406).
  • Wing vein 6 present ... 413
  • Wing vein 6 absent ... Milichiidae

413(412).
  • The costa with one break ... Psilidae
  • The costa with two breaks ... Tephritidae

414(401).
  • Wings with a discal cell; wings with a closed anal cell ... Sepsidae
  • Wings without a discal cell; wings without a closed anal cell... 415

415(414).
  • The costa unbroken ... Asteiidae
  • The costa with one break ... Chloropidae
  • The costa with two breaks ... Ephydridae

416(389).
  • Sub-costa reaching the costa independently of vein 1 ... Conopidae
  • Sub-costa joining vein 1 well short of the costa ... Asteiidae
  • Sub-costa terminating blind... 417

417(416).
  • The costa with one break ... Psilidae
  • The costa with two breaks ... Tephritidae

418(389).
  • Wings with a discal cell; wings with a more or less closed subapical cell bounded by veins 3 and 4; wings with a closed anal cell; sub-costa reaching the costa independently of vein 1; life style of species parasitic ... Conopidae
  • Wings without a discal cell; wings without a sub-apical cell; wings without a closed anal cell; sub-costa joining vein 1 well short of the costa; life style of species non-parasitic ... Asteiidae

419(375).
  • Thorax with the dorsal suture just in front of the wing bases continuous across the middle; thorax with well defined posterior calli ... 420
  • Thorax without a continuous dorsal suture; thorax without well defined posterior calli... 421

420(419).
  • Mouthparts of adults functional ... Rhinophoridae
  • Mouthparts of adults non-functional ... Oestridae

421(419).
  • Tibiae with a dorsal pre-apical bristle ... 422
  • Tibiae without a dorsal pre-apical bristle... 433

422(421).
  • winged ... 423
  • wingless ... Braulidae

423(422).
  • Wing vein 6 reaching the wing margin ... 424
  • Wing vein 6 falling short of the wing margin... 427

424(423).
  • The anal cell extending more than halfway to the wing margin ... Conopidae
  • The anal cell extending less than halfway to the wing margin... 425

425(424).
  • Life style of species parasitic ... 426
  • Life style of species non-parasitic ... Dryomyzidae

426(425).
  • On slugs and snails ... Sciomyzidae
  • On millipedes ... Phaeomyiidae

427(423).
  • Post-vertical orbital bristles convergent ... Lauxaniidae
  • Post-vertical orbital bristles parallel ... Phaeomyiidae
  • Post-vertical orbital bristles divergent... 428

428(427).
  • Adults less than 4 mm long ... AcartophthalmidaeCanacidae
  • Adults 4-8 mm long... 429
  • Adults 8-15 mm long ... Canacidae
  • Adults 15 mm or more long ... Canacidae

429(428).
  • shining, black, rather hairy flies ... 430
  • not shining black... 431

< /table>

430(429).
  • The costa unbroken ... Sepsidae
  • The costa with one break ... CanacidaeLonchaeidae
431(429).
  • The costa unbroken ... 432
  • The costa with one break ... Canacidae

432(431).
  • Life style of species parasitic ... Phaeomyiidae
  • Life style of species non-parasitic ... Sepsidae

433(421).
  • Adults less than 4 mm long ... 434
  • Adults 4-8 mm long... 441
  • Adults 8-15 mm long... 456
  • Adults 15 mm or more long... 458

434(433).
  • winged ... 435
  • wingless ... Braulidae

435(434).
  • Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells; wings with a discal cell; wings with a closed anal cell ... 436
  • Wing venation incomplete, in the sense of lacking one or more of the cells; wings without a discal cell; wings without a closed anal cell... 438

436(435).
  • Wing vein 6 present ... 437
  • Wing vein 6 absent ... Milichiidae

437(436).
  • The costa unbroken ... Chamaemyiidae
  • The costa with one break ... Acartophthalmidae

438(435).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 439
  • Wing vein 4 extending far beyond the end of the first basal cell... 440

439(438).
  • The costa with one break; life style of species non-parasitic ... Chloropidae
  • The costa with two breaks; life style of species parasitic ... Carnidae

440(438).
  • The costa unbroken ... Asteiidae
  • The costa with one break ... Chloropidae
  • The costa with two breaks ... Ephydridae

441(433).
  • Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells ... 442
  • Wing venation incomplete, in the sense of lacking one or more of the cells... 454

442(441).
  • Wing vein 1 with hairs on its upper side ... 443
  • Wing vein 1 bare... 446

443(442).
  • Wings patterned ... Platystomatidae
  • Wings unpatterned... 444

444(443).
  • Wing vein 6 present ... 445
  • Wing vein 6 absent ... Milichiidae

445(444).
  • Sub-costa reaching the costa independently of vein 1; the costa unbroken ... Sepsidae
  • Sub-costa terminating blind; the costa with one break ... Psilidae

446(442).
  • Sub-costa reaching the costa independently of vein 1 ... 447
  • Sub-costa joining vein 1 more or less where it joins the costa ... Milichiidae
  • Sub-costa joining vein 1 well short of the costa ... Milichiidae
  • Sub-costa terminating blind... 452

447(446).
  • shining, black, rather hairy flies ... 448
  • not shining black... 449

448(447).
  • The costa unbroken ... Sepsidae
  • The costa with one break ... Lonchaeidae

449(447).
  • Post-vertical orbital bristles present ... 450
  • Post-vertical orbital bristles absent ... Opomyzidae

450(449).
  • Wings patterned ... Pallopteridae
  • Wings unpatterned... 451

451(450).
  • Post-vertical orbital bristles convergent ... Chyromyidae
  • Post-vertical orbital bristles divergent ... Sepsidae

452(446).
  • Wing vein 6 present ... 453
  • Wing vein 6 absent ... Milichiidae

453(452).
  • The costa with one break ... Psilidae
  • The costa with two breaks ... Tephritidae

454(441).
  • Wings with a discal cell; wings with a closed anal cell ... Sepsidae
  • Wings without a discal cell; wings without a closed anal cell... 455

455(454).
  • The costa unbroken ... Asteiidae
  • The costa with one break ... Chloropidae
  • The costa with two breaks ... Ephydridae

456(433).
  • Sub-costa reaching the costa independently of vein 1 ... Conopidae
  • Sub-costa joining vein 1 well short of the costa ... Asteiidae
  • Sub-costa terminating blind... 457

457(456).
  • The costa with one break ... Psilidae
  • The costa with two breaks ... Tephritidae

458(433).
  • Wings with a discal cell; wings with a more or less closed subapical cell bounded by veins 3 and 4; wings with a closed anal cell; sub-costa reaching the costa independently of vein 1; life style of species parasitic ... Conopidae
  • Wings without a discal cell; wings without a sub-apical cell; wings without a closed anal cell; sub-costa joining vein 1 well short of the costa; life style of species non-parasitic ... Asteiidae

459(374).
  • Thorax with the dorsal suture just in front of the wing bases continuous across the middle; thorax with well defined posterior calli ... 460
  • Thorax without a continuous dorsal suture; thorax without well defined posterior calli... 461

460(459).
  • Mouthparts of adults functional ... Rhinophoridae
  • Mouthparts of adults non-functional ... Oestridae

461(459).
  • Tibiae with a dorsal pre-apical bristle ... 462
  • Tibiae without a dorsal pre-apical bristle... 472

462(461).
  • winged ... 463
  • wingless ... Braulidae

463(462).
  • Antennal arista characteristically, conspicuously forked at the tip ... Drosophilidae
  • Antennal arista not forked at the tip... 464

464(463).
  • Wing vein 6 reaching the wing margin ... 465
  • Wing vein 6 falling short of the wing margin... 468

465(464).
  • The anal cell extending more than halfway to the wing margin ... Conopidae
  • The anal cell extending less than halfway to the wing margin... 466

466(465).
  • Life style of species parasitic ... 467
  • Life style of species non-parasitic ... Dryomyzidae

467(466).
  • On slugs and snails ... Sciomyzidae
  • On millipedes ... Phaeomyiidae

468(464).
  • Post-vertical orbital bristles convergent ... Lauxaniidae
  • Post-vertical orbital bristles parallel ... Phaeomyiidae
  • Post-vertical orbital bristles divergent... 469

469(468).
  • Adults less than 4 mm long ... CanacidaeAcartophthalmidae
  • Adults 4-8 mm long... 470
  • Adults 8-15 mm long ... Canacidae
  • Adults 15 mm or more long ... Canacidae

470(469).
  • The costa unbroken ... 471
  • The costa with one break ... Canacidae

471(470).
  • Life style of species parasitic ... Phaeomyiidae
  • Life style of species non-parasitic ... Sepsidae

472(461).
  • winged ... 473
  • wingless ... Braulidae

473(472).
  • Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells ... 474
  • Wing venation incomplete, in the sense of lacking one or more of the cells... 495

474(473).
  • Wing vein 1 with hairs on its upper side ... 475
  • Wing vein 1 bare... 483

475(474).
  • Sub-costa reaching the costa independently of vein 1 ... 476
  • Sub-costa joining vein 1 more or less where it joins the costa... 480
  • Sub-costa joining vein 1 well short of the costa ... Milichiidae
  • Sub-costa terminating blind... 481

476(475).
  • Adults less than 4 mm long ... 477
  • Adults 4-8 mm long... 478
  • Adults 8-15 mm long... 479
  • Adults 15 mm or more long ... Conopidae

477(476).
  • The costa unbroken ... Chamaemyiidae
  • The costa with one break ... Acartophthalmidae

478(476).
  • The costa unbroken ... SepsidaeUlidiidae
  • The costa with one break ... Platystomatidae

479(476).
  • The anal cell extending more than halfway to the wing margin; wing vein 6 reaching the wing margin; life style of species parasitic; the larvae parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; wing vein 6 falling short of the wing margin; life style of species non-parasitic; the larvae saprophagous ... Ulidiidae

480(475).
  • Wings with a closed anal cell; the costa with two breaks ... Milichiidae
  • Wings without a closed anal cell; the costa unbroken ... Stenomicridae

481(475).
  • Wings with a closed anal cell ... 482
  • Wings without a closed anal cell ... Periscelididae

482(481).
  • Wing vein 6 present; the costa with one break ... Psilidae
  • Wing vein 6 absent; the costa with two breaks ... Milichiidae

483(474).
  • Sub-costa reaching the costa independently of vein 1 ... 484
  • Sub-costa joining vein 1 more or less where it joins the costa... 491
  • Sub-costa joining vein 1 well short of the costa ... Milichiidae
  • Sub-costa terminating blind... 492

484(483).
  • Adults less than 4 mm long ... 485
  • Adults 4-8 mm long... 486
  • Adults 8-15 mm long... 490
  • Adults 15 mm or more long ... Conopidae

485(484).
  • The costa unbroken ... Chamaemyiidae
  • The costa with one break ... Acartophthalmidae

486(484).
  • Post-vertical orbital bristles present ... 487
  • Post-vertical orbital bristles absent ... Opomyzidae

487(486).
  • Wings patterned ... 488
  • Wings unpatterned... 489

488(487).
  • The costa unbroken ... Ulidiidae
  • The costa with one break ... Pallopteridae

489(487).
  • Post-vertical orbital bristles convergent ... Chyromyidae
  • Post-vertical orbital bristles parallel ... Ulidiidae
  • Post-vertical orbital bristles divergent ... SepsidaeUlidiidae
490(484).
  • The anal cell extending more than halfway to the wing margin; wing vein 6 reaching the wing margin; life style of species parasitic; the larvae parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; wing vein 6 falling short of the wing margin; life style of species non-parasitic; the larvae saprophagous ... Ulidiidae

491(483).
  • Wings with a closed anal cell; the costa with two breaks ... Milichiidae
  • Wings without a closed anal cell; the costa unbroken ... Stenomicridae

492(483).
  • Wings with a closed anal cell ... 493
  • Wings without a closed anal cell ... Periscelididae

493(492).
  • Wing vein 6 present ... 494
  • Wing vein 6 absent ... Milichiidae

494(493).
  • The costa with one break ... Psilidae
  • The costa with two breaks ... Tephritidae

495(473).
  • Wing vein 4 very short, extending little beyond the end of the first basal cell ... 496
  • Wing vein 4 extending far beyond the end of the first basal cell... 498

496(495).
  • The costa unbroken ... 497
  • The costa with one break ... Chloropidae
  • The costa with two breaks ... Carnidae

497(496).
  • Sub-costa reaching the costa independently of vein 1 ... Conopidae
  • Sub-costa joining vein 1 more or less where it joins the costa ... Stenomicridae
  • Sub-costa terminating blind ... Periscelididae

498(495).
  • Wings with a closed anal cell ... 499
  • Wings without a closed anal cell... 500

499(498).
  • The anal cell extending more than halfway to the wing margin; wing vein 6 reaching the wing margin; life style of species parasitic ... Conopidae
  • The anal cell extending less than halfway to the wing margin; wing vein 6 falling short of the wing margin; life style of species non-parasitic ... Sepsidae

500(498).
  • Post-vertical orbital bristles present ... 501
  • Post-vertical orbital bristles absent... 503

501(500).
  • The costa unbroken ... 502
  • The costa with one break ... Chloropidae

502(501).
  • Sub-costa joining vein 1 more or less where it joins the costa ... Stenomicridae
  • Sub-costa joining vein 1 well short of the costa ... Asteiidae
  • Sub-costa terminating blind ... Periscelididae

503(500).
  • The costa with one break ... Chloropidae
  • The costa with two breaks ... Ephydridae

504(369).
  • Antennae having the terminal segment annulated ... 505
  • Antennae with a non-annulated terminal segment... 510

505(504).
  • The fork of wing vein 3 broad, its lower branch reaching the wing margin well below the apex ... 506
  • The fork of wing vein 3 narrow, its lower branch reaching the wing margin near the apex... 507

506(505).
  • Ocelli present; the costa not extending around the entire wing; tibiae without spurs ... Stratiomyidae
  • Ocelli absent; the costa extending around the entire wing; tibiae spurred ... Tabanidae

507(505).
  • Wings with the fourth posterior cell open ... 508
  • Wings with the fourth posterior cell closed... 509

508(507).
  • The costa extending around the entire wing ... Xylophagidae
  • The costa not extending around the entire wing ... Stratiomyidae

509(507).
  • The costa extending around the entire wing ... Xylomyidae
  • The costa not extending around the entire wing ... Stratiomyidae

510(504).
  • Antennae 1 segmented ... Phoridae
  • Antennae 2 segmented ... Acroceridae
  • Antennae 3 segmented... 511
  • Antennae 8 to 10 segmented ... Thaumaleidae
  • Antennae 11 to 15 segmented... 526

511(510).
  • The costa extending around the entire wing ... 512
  • The costa not extending around the entire wing... 520

512(511).
  • Mouthparts adapted for piercing ... 513
  • Mouthparts non-piercing... 518

513(512).
  • The top of the head with a marked depression between the eyes, within which the ocellar triangle projects ... 514
  • The top of the head with no marked depression between the eyes... 516

514(513).
  • Feet with a triple pad beneath the tarsal claws ... 515
  • Feet without a triple pad ... Asilidae

515(514).
  • The larvae saprophagous ... Athericidae
  • The larvae predatory ... Rhagionidae

516(513).
  • Feet with a triple pad beneath the tarsal claws ... 517
  • Feet without a triple pad ... Therevidae

517(516).
  • The larvae saprophagous ... Athericidae
  • The larvae predatory ... Rhagionidae

518(512).
  • Feet with a triple pad beneath the tarsal claws; the larvae aquatic ... Athericidae
  • Feet without a triple pad; the larvae terrestrial... 519

519(518).
  • Wings with 7 cells between vein 3 and the anal cell; sub-costa joining vein 1 more or less where it joins the costa; life style of species parasitic; the larvae parasitic ... Bombyliidae
  • Wings with 8 cells between vein 3 and the anal cell; sub-costa reaching the costa independently of vein 1; life style of species non-parasitic; the larvae predatory ... Therevidae

520(511).
  • Wings with a discal cell ... 521
  • Wings without a discal cell... 523

521(520).
  • Wings with a more or less closed subapical cell bounded by veins 3 and 4 ... 522
  • Wings without a sub-apical cell ... Empididae

522(521).
  • Antennae aristate; wing vein 3 not forked; life style of species parasitic; the larvae acephalic; the pupae enclosed within a puparium ... Pipunculidae
  • Antennae not aristate; wing vein 3 distally forked; life style of species non-parasitic; the larvae hemicephalic; the pupae without a puparium ... Scenopinidae

523(520).
  • Mouthparts of adults functional; the leading edge veins not noticeably stronger than the rest; life style of species non-parasitic ... 524
  • Mouthparts of adults non-functional; the leading edge veins markedly stronger than the rest; life style of species parasitic ... Acroceridae

524(523).
  • Wings with a closed anal cell ... 525
  • Wings without a closed anal cell ... Lonchopteridae

525(524).
  • Wing vein 7 present; the larvae acephalic; the pupae enclosed within a puparium ... Opetiidae
  • Wing vein 7 absent; the larvae hemicephalic; the pupae without a puparium ... Dolichopodidae

526(510).
  • stilt-legged (legs long and thin); eyes rounded, well separated; the costa not extending around the entire wing ... Chaoboridae
  • not stilt-legged (legs of about average length and thickness); eyes asymmetric, nearly or quite connected above the antennae; the costa extending around the entire wing ... Thaumaleidae

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. British insects: the families of Diptera. Version: 1st January 2012. http://delta-intkey.com’.

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