Elateriformia (Coleoptera)


J. F. Lawrence, A. M. Hastings, M. J. Dallwitz, T. A. Paine and E. J. Zurcher


Classification. Polyphaga: Elateriformia.

Distribution. Although the Limnichinae are widely distributed, the remaining limnichid subfamilies have more restricted distributions. Cephalobyrrhinae include the New World Throscinus, Cephalobyrrhus from Japan and India and Parathroscinus from Oriental and Australian regions. Hyphalinae are restricted to the northeastern coast of Australia, North Island of New Zealand, Norfolk and Lord Howe Islands and the Ryukyu Archipelago, Japan. Thaumastodinae are known from from the West Indies, western Mexico, Japan, southeast Asia, the East Indies and northern Australia.

Biogeographic regions: Nearctic, Palearctic, Neotropical, Afrotropical, Oriental, Australian.

Biology. Most Limnichidae occur in damp soil and leaf litter, often in riparian or littoral habitats; their larvae tunnel in soil and appear to feed on algae or bryophytes. Thaumastodinae, and probably Cephalobyrrinae as well, occur on damp sand in the marine littoral zone, and Hyphalinae are restricted to inter-tidal rocks.


Britton, E. B. 1971. A new intertidal beetle (Coleoptera: Limnichidae) from the Great Barrier Reef. Journal of Entomology (B) 40: 83–91.

Britton, E. B. 1977. Three new intertidal species of Limnichidae (Coleoptera) from New Zealand. Records of the Auckland Museum 14: 81–85.

Brown, H. P. 1991. Limnichidae (Dryopoidea), pp. 401–402. IN: F. W. Stehr (ed.), Immature Insects. Vol. 2. Kendall/Hunt Publishing Co., Dubuque, Iowa.

Champion, G. C. 1924. On a new subfamily of clavicorn Coleoptera. Entomologist's Monthly Magazine 60: 25–29.

Champion, G. C. 1925. Some Indian (and Tibetan) Coleoptera (17). Entomologist's Monthly Magazine, 61: 169–181.

Deleve, J. 1973. Limnichidae, Dryopidae et Elminthidae des Iles Philippines et de l'Archipel Bismarck (Insecta, Coleoptera, Dryopoidea). Steenstrupia 3: 17–30.

Hinton, H. E. 1939. A contribution to the classification of the Limnichidae (Coleoptera). Entomologist, 72: 181–186.

Hinton, H. E. 1939. An inquiry into the natural classification of the Dryopoidea, based partly on a study of their internal anatomy. Transactions of the Royal Entomological Society of London, 87: 133–184, pl. 1

Hinton, H. E. 1939. On some new genera and species of neotropical Dryopoidea (Coleoptera). Transactions of the Royal Entomological Society of London, 89: 23–46.

Kasap, H. and R. A. Crowson 1975. A comparative anatomical study of Elateriformia and Dascilloidea (Coleoptera). Transactions of the Royal Entomological Society of London 126: 441–495.

Lawrence, J. F. 1987. Notes on the classification of some Australian Elateriformia (Coleoptera). Journal of the Australian Entomological Society 26: 360.

Paulus, H. F. 1979. 47. Familie: Byrrhidae, pp. 328–350. IN: H. Freude, K. W. Harde and G. A. Lohse (eds.), Die Käfer Mitteleuropas. Band 6. Diversicornia. Goecke & Evers, Krefeld.

Pic, M. 1914. Pars 58. Dascillidae, Helodidae, Eucinetidae. IN: S. Schenkling (ed.), Coleopterorum Catalogus. W. Junk, Berlin, 65 pp.

Pütz, A. 1998. Limnichidae: I. Check list and bibliography of the Limnichidae of China and neighboring countries (Coleoptera), pp. 337–339. IN: M. A. Jäch and L. Ji (eds.), Water Beetles of China. Vol. II. Zoologisch-Botanische Gesellschaft in Österreich und Wiener Coleopterologenverein, Vienna.

Pütz, A. 1998. Limnichidae: II. Taxonomic revision of the genus Cephalobyrrhus Pic (Coleoptera), pp. 341–371. IN: M. A. Jäch and L. Ji (eds.), Water Beetles of China. Vol. II. Zoologisch-Botanische Gesellschaft in Österreich und Wiener Coleopterologenverein, Vienna.

Sato, M. 1966. The limnichid-beetles of Japan. Transactions of the Shikoku Entomological Society 9: 55–62.

Satô, M. 1997. Occurrence of a new Hyphalus (Coleoptera, Limnichidae) from the Ryukyu Archipelago, Japan. Elytra, Tokyo 25: 109–112.

Shepard, W. 2000. 50. Limnichidae. IN: R. H. Arnett, Jr., Jr. and M. C. Thomas (eds.), American Beetles. CRC Press, Gainesville, Florida (in press).

Spangler, P. J. 1995. A review and two new species of the genus Pseudeucinetus Heller from Southeast Asia and a world checklist of the Thaumastodinae (Coleoptera, Limnichidae). Special Bulletin of the Japanese Society of Coleopterology 4: 395–405.

Spilman, T. J. 1959. A study of the Thaumastodinae, with one new genus and two new species (Limnichidae). Coleopterists' Bulletin, 13: 111–122. Mexico. Pan-Pacific Entomologist, 48: 108–115.

Spilman, T. J. 1972. A new genus and species of jumping shore beetle from Mexico (Coleoptera: Limnichidae). Pan-Pacific Entomologist 48: 108–115.

Wooldridge, D. P. 1975. A key to the New World genera of the beetle family Limnichidae. Entomological News, 86: 1–4.

Wooldridge, D. P. 1976. New World Limnichinae I: a revision of the genus Physemus LeConte (Coleoptera: Limnichidae). Coleopterists Bulletin 30: 177–182.

Wooldridge, D. P. 1977. New World Limnichinae, II: Cephalobyrrhinus Pic (Coleoptera: Limnichidae). Entomological News, 88: 29–32.

Wooldridge, D. P. 1977. New World Limnichinae, III. A revision of Limnichites Casey (Coleoptera: Limnichidae). Great Lakes Entomologist, 10: 179–189.

Wooldridge, D. P. 1980. New World Limnichinae, V. Corrinea, a new Neotropical genus (Limnichidae). Coleopterists Bulletin, 34: 69–78.

Wooldridge, D. P. 1981. New world Limnichinae, VI. A revision of Limnichoderus Casey (Coleoptera: Dryopoidea: Limnichidae). Journal of the Kansas Entomological Society, 54: 171–191.

Wooldridge, D. P. 1981. Three new species of Throscinus LeConte, with notes on other species (Coleoptera: Limnichidae: Cephalobyrrhinae. Coleopterists Bulletin, 35: 217–222.

Wooldridge, D. P. 1982. New World Limnichinae, VII: Phalacrichus Sharp - a recharacterization and eight new species (Coleoptera: Dryopoidea: Limnichidae). Coleopterists Bulletin, 36: 381–389.

Wooldridge, D. P. 1983. Limnichinae VIII. Paralimnichus Deleve (Coleoptera: Dryopoidea: Limnichidae). Journal of the Kansas Entomological Society 56: 232–233.

Wooldridge, D. P. 1984. Parathroscinus, a new genus of beetles from Southeast Asia (Limnichidae: Cephalobyrrhinae). Journal of the New York Entomological Society, 92: 121–124.

Wooldridge, D. P. 1987. New World Limnichinae, IX: a revision of Neotropical Byrrhinus Motschulsky (Coleoptera: Dryopoidea: Limnichidae). Coleopterists Bulletin, 41: 303–314.

Zaitzev, P. 1910. Pars 17. Dryopidae, Cyathoceridae, Georyssidae, Heteroceridae. IN: S. Schenkling (ed.), Coleopterorum Catalogus. W. Junk, Berlin, 68 pp.

General appearance. Total length 0.8–4.5 mm. Ratio of body length to greatest body width 1.3–2.15. Body slightly flattened to moderately convex, or strongly convex. Sides of body not evenly curved, or evenly curved. Body not capable of conglobation (rolling into a ball). Upper surfaces of body glabrous or subglabrous, or clothed with distinct hairs, setae or scales. Vestiture of upper surfaces not including stiff, erect, dark bristles; not including scales or scale-like setae. Upper surfaces of body without deep foveae. Prothorax, metathorax and-or abdomen without extrusible glands. Underside of body without hydrofuge surface(s).

Head. Ratio of head length to its greatest width (excluding eyes) 1 or less. Head width just behind eyes not distinctly greater than prothoracic width. Head not or slightly declined, or moderately to strongly declined; not entirely concealed from above by pronotum; without elongate rostrum; not abruptly constricted posteriorly. Temples absent or not closely adpressed to prothorax; absent. Transverse occipital ridge or carina absent, or present. Occiput without stridulatory file. Longitudinal axis of head (from occipital foramen to mouth cavity) inclined at an angle of less than 45 degrees, or inclined at an angle of 45 to 90 degrees, or inclined at an angle of more than 90 degrees. Frontal region not to moderately, gradually declined, or strongly deflexed, vertical or inflexed from behind eyes. Occipital region without median longitudinal groove or line (endocarina). Frontal region without median groove or line (endocarina). Head without ocelli.

Compound eyes present. Eyes not or only slightly protuberant, or strongly protuberant. Vertical diameter of eye less than 2 times horizontal diameter. Eyes finely facetted, or coarsely facetted; without interfacetal setae. Ommatidium of the exocone type. Eye entire. Anterior or mesal edge of eye not or only barely emarginate, or deeply emarginate or strongly divided by canthus. Posterior edge of eye not or barely emarginate.

Antennal insertions exposed from above, or concealed from above; moderately to widely separated, or narrowly separated. Antennae not borne on raised tubercles. Subantennal groove or cavity on head absent or very weakly developed, or well developed. Frontoclypeal suture absent or incomplete, or indistinctly impressed, or distinctly impressed; straight, slightly curved or angulate. Clypeus not laterally emarginate. Anterior edge of clypeus or clypeolabrum straight to convex. Mouth cavity anteriorly or anteroventrally oriented, or ventrally or posteroventrally oriented. Pregular area without laterally opening cavities. Head ventrally without paired subgenal ridges, or with paired subgenal ridges. Head without anteriorly-projecting genal processes. Gular sutures widely separated or absent. Corporotentorium narrow, or incomplete or absent; without median process. Cervical sclerites present.

Antennae. Number of antennomeres 7, or 11. Antennae when posteriorly extended not reaching middle of prothorax, or reaching beyond middle of prothorax but not middle of elytra. Antennae serrate, or incrassate or clavate, or capitate. Antennomeres 3, 4 or 5 to 10 without or with single rami (uniramose). Antennae at least partly pubescent or with obvious modifications. Antennal modifications beginning on antennomere 5, or antennomere 5 or beyond. First antennomere (scape) less than 3 times as long as 2nd (pedicel). Antenna not geniculate; without apical club, or with weak apical club. Antennal club 1-segmented, or 2-segmented, or 3-segmented, or 4-segmented, or 5-segmented, or with 6 or more segments; not 5-segmented or with 2nd segment subequal to or larger than 1st; loose; not lamellate; not or slightly serrate; not or slightly flattened, or distinctly flattened; not preceded by a cupule.

Mouthparts. Labrum at least partly visible; free, membranous or separated by suture. Major portion of labrum strongly transverse, or slightly transverse or subquadrate. Apex of labrum subtruncate to slightly convex, or strongly convex, narrowly rounded or acute. Labrum moderately to heavily sclerotized, except at base and-or apex. Mouthparts not forming a piercing or sucking tube. Mandibles present. Mandible short and broad. Mandibular apex moderately to strongly, gradually curved mesally, or strongly and abruptly curved mesally; unidentate, truncate or rounded, or bidentate or bilobed, or multidentate or multilobed. Dorsal part of mandible without tubercle; without setose cavity. Incisor edge of mandible simple, or with single tooth, or with 2 or more teeth. Mandible with well developed mola; with well developed prostheca. Prostheca absent or without articulated, sclerotized process, or including articulated, sclerotized process. Maxilla with distinct galea and lacinia. Maxillary lobe(s) not stylet-like. Apex of galea or maxillary lobe densely setose or spinose, or without or with few setae or spines; without heavily sclerotized teeth or hooks. Lacinia without hook(s) or spine(s), or with apical or subapical hook(s) or spine(s). Apical maxillary palpomere cylindrical to fusiform; at least as wide as or longer than preapical one. Maxillary palp without complex palp organ. Apical labial palpomere cylindrical to fusiform, or slightly to strongly expanded apically. Ligula undivided or finely cleft.

Prothorax. Ratio of pronotal length to greatest pronotal width 0.3–0.65. Prothorax widest at middle, or posteriorly. Sides of prothorax more or less straight, or moderately to strongly curved, or straight posteriorly, curved anteriorly. Prothorax not laterally compressed to form cavities for legs. Sides of prothorax not or slightly explanate. Base of prothorax not or slightly narrower than elytral bases. Greatest prothoracic width not or slightly narrower than greatest elytral width, or distinctly narrower than greatest elytral width. Lateral pronotal carinae complete; simple; visible for their entire lengths from above, or not visible for their entire length from above; without a raised margin, or with a raised margin or narrow bead. Lateral portion of prothorax without deep pit. Pronotum without anterolateral callosities. Anterior angles of pronotum absent or not produced forward, or distinctly produced forward; absent, right or rounded, not produced, or produced and narrowly rounded or acute. Posterior angles of pronotum obtuse or right, or moderately to strongly acute; not produced and acute, or strongly produced and narrowly acute. Posterior edge of pronotum more or less straight or evenly rounded, or moderately to strongly produced forming mesal lobe, or distinctly sinuate or variously lobed; simple; not or vaguely margined. Discal carinae of pronotum absent. Pronotal disc without paired basal impressions, or with paired basal impressions. Pronotum without median longitudinal groove or line. Hypomeron without pit.

Anterior portion of prosternum at midline shorter than prosternal process, or as long as prosternal process, or longer than prosternal process. Lateral portion of prosternum in front of coxae shorter than mid length of procoxal cavity, or as long as mid length of procoxal cavity, or longer than mid length of procoxal cavity. Anterior edge of prosternum not produced anteriorly, or distinctly produced forming chin piece. Prosternum in front of coxae flat to moderately convex, or strongly convex without carina. Prosternum in front of coxae without paired lines or carinae, or with paired lines or carinae. Anterior edge of prosternum without mesal excavation. Anterolateral or ventrolateral portions of prothorax without cavities or grooves, or with broad cavities, or with narrow grooves. Prothoracic cavities absent, or external, open anteriorly, visible from above. Prothoracic grooves absent, or longitudinal or oblique, elsewhere on hypomera or prosternum. Prosternal process complete; narrowed apically, or parallel-sided; flat, concave, or only slightly elevated or curved behind coxae, or slightly to strongly elevated but not curved behind; moderately to strongly overlapping mesoventrite. Apex of prosternal process acute or narrowly rounded, or broadly rounded, angulate or truncate. Prosternal process without transverse groove. Accessory (mesal) procoxal articulation absent. Ventral portion of prothorax on each side with notosternal suture only. Propleuron not extending to anterior edge of prothorax. Propleuron or pleurotrochantin not extending behind coxa. Procoxae not or slightly projecting below prosternum. Procoxa without or with short concealed lateral extension. Procoxal cavities present, procoxae countersunk. Procoxal cavity strongly transverse. Procoxal cavities at middle moderately to widely separated. Procoxal cavities externally open; broadly open. Postcoxal projection absent or very short. Procoxal cavities without narrow lateral extensions. Procoxal cavities internally open. Prothoracic trochantin or pleurotrochantin at least partly exposed. Promesothoracic clicking mechanism absent.

Elytra. Elytra present. Ratio of elytral length to greatest elytral width 1–1.65. Ratio of elytral length to pronotal length 2.4–4.7. Elytra apunctate, irregularly punctate, or with 5 or fewer distinct puncture rows or striae; without scutellary striole. Sutural stria absent or not deeply impressed near apex. Abdominal tergites exposed by elytra none or apex of 1. Elytral apices meeting or almost meeting at the suture. Elytral suture not deflected near apex. Elytral apex without internal interlocking tongue. Epipleuron absent or incomplete, or complete; not or gradually narrowed, or abruptly narrowed or excavated. Lateral edge of elytron straight or weakly sinuate.

Pterothorax. Scutellum well developed, or highly reduced; abruptly elevated; anteriorly simple; posteriorly narrowly rounded or acute, or broadly rounded or obtusely angulate. Mesoscutum without stridulatory file. Mesoventrite with paired procoxal rests. Paired mesoventral procoxal rests moderately to strongly oblique, or vertical. Anterior edge of mesoventrite without prosternal rest. Mesoventrite not divided by longitudinal groove or discrimen, or at least partly divided by longitudinal groove or discrimen. Anterior edge of mesoventrite at midline on same plane as metaventrite. Mesoventral cavity moderately large and shallow, or moderately to very large and deep. Mesocoxa not conical and projecting. Mesocoxal cavities present, mesocoxae countersunk. Mesocoxal cavities at middle moderately to widely separated. Mesocoxae separated by more than shortest diameter of coxal cavity. Mesocoxal cavities circular to slightly transverse; not or slightly oblique. Mesoventrite separated by complete sutures from mesepisterna, or partly or completely fused to mesepisterna. Mesepisterna distinctly separated at midline; without deep pockets. Mesepimeron not visible from above. Mesocoxal cavities open laterally; not partly closed by metepisterna. Mesoventral process extending at least to middle of mesocoxal cavity. Mesometaventral junction a straight line, or an anteriorly curved, angulate or acute line, or a complex fitting.

Metaventral discrimen or median line moderately to very long. Paired postcoxal lines of metaventrite absent, or present. Postcoxal lines of metaventrite absent, or arched but not or slightly recurved. Metaventrite longer than first abdominal ventrite, or not longer than first abdominal ventrite. Postcoxal pits of metaventrite absent. Metaventrite flat to slightly convex, or moderately to strongly convex. Transverse groove of metaventrite absent, or present. Anterior edge of metaventrite without transverse carina between mesocoxal cavities. Exposed portion of metepisternum short and broad, or moderately elongate, or very long and narrow or absent. Metacoxae contiguous or narrowly separated, or widely separated; not extending laterally to meet elytra or sides of body, or extending laterally to meet elytra or sides of body; completely separated from metaventrite by suture. Metacoxal plates well developed, more or less uniform, or well developed mesally, weak laterally, or absent; not concealing most of basal abdominal ventrite. Metacoxae not greatly enlarged, or greatly enlarged; horizontally oriented, or obliquely oriented. Lateral arms of metendosternite short or absent, or moderately to very long. Metendosternal laminae absent. Ventrolateral processes of metendosternite absent or weakly developed. Anterior process of metendosternite moderately long, or short or absent. Anterior tendons of metendosternite moderately or very close together, or widely separated but not on lateral arms, or on lateral arms or not apparent. Apical portion of metendosternite not or only slightly emarginate.

Hind wing. Hind wing well developed, or highly reduced or absent; with normal transverse folds. Radial cell of hind wing well developed, or highly reduced or absent; shorter and broader, or incomplete or absent. Inner posterior angle formed at base of radial cell acute. Radial cell not forming equilateral triangle. Ratio of length of apical area to total wing length 0.36–0.5. Medial bar of hind wing not crossed by fold. Free veins in medial area of hind wing 4, or 3 or fewer. Oblongum cell of hind wing absent. Medial fleck of hind wing absent; absent or not partly bisected by a vein. Wedge cell of hind wing reduced, or absent. Anal lobe of hind wing absent. Posterior edge of hind wing without fringe of long hairs.

Legs. Femoral attachment of mid trochanter transverse or slightly oblique, or strongly oblique with base of femur separate from coxa. Mesotrochanter not reduced or concealed from below. Metafemur not much wider than mesofemur. Mesotibia not strongly widened. Outer edge of mesotibia simple, crenulate or denticulate. Outer subapical edge of mesotibia without antenna cleaner. Preapical surfaces of mesotibia without ridges or combs. Outer apical angle of mesotibia simple or slightly produced, without lobe, teeth or spines. Mesotibial spurs glabrous or absent. Mesotarsus with 5 distinct tarsomeres (pentamerous), or with 4 distinct tarsomeres and reduced penultimate one (pseudotetramerous), or with 4 distinct tarsomeres (tetramerous). Tarsomeres on hind leg at least as many as on mid leg. Tarsomeres on fore leg at least as many as on mid leg, or 1 fewer than on mid leg. Mesotarsomere 1 well developed and visible. Preapical mesotarsomeres together longer than apical one, or shorter than apical one. Penultimate mesotarsomere not distinctly shorter than antepenultimate, or distinctly shorter than antepenultimate. Ventral mesotarsal lobes absent, or on more than one tarsomere. Mesotarsal claws paired; subequal in length and similar in form and angle of inclination; simple. Appendage on each tarsal claw absent. Mesotarsal claws without setae near base. Mesotarsal empodium absent or with 2 or fewer setae. Inner subapical edge of protibia without antenna cleaner. Hind legs without swimming hairs. Preapical surfaces of metatibia without ridges or combs.

Abdomen. Number of abdominal ventrites 5. Number of basal ventrites connate three, or five or six. Abdominal sternite 2 apparently absent. First ventrite not completely divided by metacoxae. Suture between ventrites 1 and 2 distinct. Suture between ventrites 2 and 3 distinct. Ventrite 4 articulated with or connate with both 3 and 5. Postcoxal lines on ventrite 1 absent, or 1 pair, strongly curved or recurved, or 1 pair, straight or slightly curved. Ventrite 1 not much longer than 2. Abdominal process acute or narrowly rounded, or broadly rounded or angulate, or truncate or slightly emarginate, or absent. Ventrite 5 in female without circular depression. Posterior edge of ventrite 5 not crenulate, or crenulate. Last visible tergite and-or sternite (7 or 8) not forming terminal spine. Subapical abdominal luminous organ absent. Ventrites without setose patches or foveae. Functional spiracles on abdominal segment 8 present. Anterior edge of sternite 8 in male without median strut, or with median strut. Anterior edge of sternite 9 in male without median strut, or with median strut (spiculum gastrale). Tergite 9 in male completely fused to tergite 10. Tergite 10 in male completely membranous or fused to tergite 9.

Aedeagus trilobate; symmetrical, or asymmetrical. Anterior edge of tegmen or phallobase without struts, or with single strut. Parameres individually articulated to phallobase or base of penis; not outwardly hooked. Penis without dorsal and ventral lobes. Anterior edge of penis without struts, or with single strut, or with paired struts.

Illustrations. • Cephalobyrrhus. Cephalobyrrhus gibbicollis Champion. Locality: India. Artist: Terzi. Reference: Champion 1925. • Hyphalus. Hyphalus insularis Britton. Locality: Australia. Artist: S. Monteith. Copyright CSIRO. Reference: Britton 1971. • Limnichus. Limnichus australis Erichson. Locality: Australia. Artist: F. Nanninga. Copyright CSIRO. Reference: Britton 1970. • Ersachus. Ersachus erichsonianus Sharp. Locality: Central America. Artist: O. F. Tassart. Reference: Hinton 1939. • Paralimnichus. Paralimnichus castaneus (Lea). Locality: Australia. Photo: K. Smith. Copyright CSIRO. • Pseudeucinetus. Pseudeucinetus sp. Locality: Sulawezi. Photo: K. Smith. Copyright CSIRO.

The interactive key provides access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, and summaries of attributes within groups of taxa.

Cite this publication as: ‘Lawrence, J.F., Hastings, A.M., Dallwitz, M.J., Paine, T.A., and Zurcher, E.J. 2000 onwards. Elateriformia (Coleoptera): descriptions, illustrations, identification, and information retrieval for families and subfamilies. Version: 9th October 2005. http://delta-intkey.com’.