Classification. Polyphaga: Elateriformia.
Distribution. Cardiophorine Elateridae are cosmopolitan in distribution.
Biogeographic regions: Nearctic, Palearctic, Neotropical, Afrotropical, Oriental, Australian.
Biology. Larvae of Cardiophorinae occur in soil and are very distinctive, with a very slender, worm-like body and peculiar, externally toothed mandibles; these larvae are predaceous.
Calder, A. A. 1996. Click Beetles: Genera of Australian Elateridae (Coleoptera). Monographs on Invertebrate Taxonomy Vol. 2. CSIRO Publishing, Collingwood, Victoria, x + 401 pp.
Candèze, E. 1860. Monographie des Élatérides. Vol. 3. Memoires de la Société Royale des Sciences de Liége 15, 512 pp., 5 pls.
Dolin, V. G. 1975. Wing venation of click-beetles (Coleoptera, Elateridae) and its importance for taxonomy of the family. Zoologicheskii Zhurnal 54: 1618–1633 (in Russian).
Dolin, V. G. 1978. Identification Table for Click Beetles of the Fauna of the USSR. Urozhai, Kiev. 126 pp. (In Russian; translated by El-Ahram Center for Scientific Translations, Washington, D.C.).
Dolin, V. G. 1978. Phylogeny of click beetles (Coleoptera, Elateridae). Vestnik Zoologii 1978 (3): 3–12.
Emden, F. I. van 1945. Larvae of British beetles. V. Elateridae. Entomologist's Monthly Magazine 81: 13–37.
Gur'yeva,Ye. L. 1969. Some trends in the evolution of click beetles (Coleoptera, Elateridae). Entomologicheskiye Obozreniye 48: 263–272 (in Russian; translation in Entomological Review, Washington 48: 154–159).
Gur'yeva, Ye. L. 1974. Thoracic structure of click beetles (Coleoptera: Elateridae) and the significance of the structural characters for the system of the family. Entomologicheskoye Obozreniye 53: 96–113 (in Russian; translation in Entomological Review, Washington 53: 67–79).
Hyslop, J. A. 1917. The phylogeny of the Elateridae based on larval characters. Annals of the Entomological Society of America 10: 241–263.
Johnson, P. J. 2000. 63. 63. Elateridae. IN: R. H. Arnett, Jr., Jr. and M. C. Thomas (eds.), American Beetles. CRC Press, Gainesville, Florida (in press).
Lohse, G. A. 1979. 34. Familie: Elateridae, pp. 103–186. IN: H. Freude, K. W. Harde and G. A. Lohse (eds.), Die Käfer Mitteleuropas. Band 6. Diversicornia. Goecke & Evers, Krefeld.
Nakane, T. and T. Kishii 1956. On the subfamilies of Elateridae from Japan (Coleoptera). Kontyû 24: 201–206.
Ohira, H. 1962. Morphological and Taxonomic Study on the Larvae of Elateridae in Japan (Coleoptera). H. Ohira, Okazaki City, Japan, 179 pp 6 pls.
Schenkling, S. 1925. Pars 80. Elateridae I. IN: S. Schenkling (ed.), Coleopterorum Catalogus. W. Junk, Berlin, pp. 1–263.
Schwarz, O. 1906–1907. Coleoptera Fam. Elateridae. IN: P. Wytsman (ed.), Genera Insectorum. Fascicule 46. P. Wytsman, Brussels, 370 pp., 6 pls.
General appearance. Total length 3–10 mm. Ratio of body length to greatest body width 2.65–3.35. Body slightly flattened to moderately convex, or strongly convex. Sides of body not evenly curved. Body not capable of conglobation (rolling into a ball). Upper surfaces of body 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. 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 at apex only. Occipital region without median longitudinal groove or line (endocarina), or with 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. Vertical diameter of eye less than 2 times horizontal diameter. Eyes finely facetted; without interfacetal setae. Ommatidium of the exocone type. Eye entire. Anterior or mesal edge of eye not or only barely emarginate. Posterior edge of eye not or barely emarginate.
Antennal insertions 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. Frontoclypeal suture absent or incomplete. Clypeus not laterally emarginate. Anterior edge of clypeus or clypeolabrum straight to convex, or concave to shallowly emarginate. 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; without median process. Cervical sclerites present.
Antennae. Number of antennomeres 11. Antennae when posteriorly extended reaching beyond middle of prothorax but not middle of elytra. Antennae filiform, or serrate. 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 3 (rarely 2), or antennomere 4. First antennomere (scape) less than 3 times as long as 2nd (pedicel). Antenna not geniculate; without apical club.
Mouthparts. Labrum at least partly visible; free, membranous or separated by suture. Major portion of labrum strongly transverse. Apex of labrum subtruncate to slightly convex. 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, or moderately elongate. Mandibular apex moderately to strongly, gradually curved mesally; unidentate, truncate or rounded, or bidentate or bilobed. Dorsal part of mandible without tubercle; without setose cavity. Incisor edge of mandible simple, or with single tooth. Mandible without mola; with well developed prostheca, or with reduced prostheca, or without prostheca. Prostheca absent or without 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; without heavily sclerotized teeth or hooks. Lacinia without hook(s) or spine(s). Apical maxillary palpomere cylindrical to fusiform, or slightly expanded and truncate to subtriangular, or securiform to cultriform; 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, or indistinct or absent.
Prothorax. Ratio of pronotal length to greatest pronotal width 0.8–1.1. Prothorax widest anteriorly, or at middle. Sides of prothorax more or less straight, or moderately to strongly curved, or straight posteriorly, curved anteriorly, or sinuate. 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. Lateral pronotal carinae incomplete, or absent; simple; 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; absent, right or rounded, not produced. Posterior angles of pronotum moderately to strongly acute; strongly produced and narrowly acute. Posterior edge of pronotum distinctly sinuate or variously lobed; simple; not or vaguely margined. Discal carinae of pronotum absent, or located on posterior angles only, or basal but mesad of posterior angles. 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 longer than prosternal process. Lateral portion of prosternum in front of coxae 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. Anterior edge of prosternum without mesal excavation. Anterolateral or ventrolateral portions of prothorax without cavities or grooves. Prothoracic cavities absent. Prothoracic grooves absent. Prosternal process complete; narrowed apically, or parallel-sided, or gradually expanded and then narrowed; flat, concave, or only slightly elevated or curved behind coxae, or strongly elevated and curved dorsally behind coxae; 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 cavity circular or longer than wide. Procoxal cavities at middle moderately to widely separated. Procoxal cavities externally open; narrowly open. Postcoxal projection moderately long but not meeting prosternal process. Procoxal cavities without narrow lateral extensions. Procoxal cavities internally open. Prothoracic trochantin or pleurotrochantin completely concealed or absent. Promesothoracic clicking mechanism present.
Elytra. Elytra present. Ratio of elytral length to greatest elytral width 1.94–2.75. Ratio of elytral length to pronotal length 2.18–3.33. Elytra with more than 5 distinct puncture rows, or with more than 5 distinct impressed striae; without scutellary striole. Number elytral puncture rows or striae 9. 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 complete; not or gradually narrowed. Lateral edge of elytron straight or weakly sinuate.
Pterothorax. Scutellum well developed; abruptly elevated; anteriorly simple, or notched; posteriorly narrowly rounded or acute. Mesoscutum without stridulatory file. Mesoventrite without paired procoxal rests, or with paired procoxal rests. Paired mesoventral procoxal rests absent, horizontal or slightly oblique. Anterior edge of mesoventrite without prosternal rest. Mesoventrite not divided by longitudinal groove or discrimen. Anterior edge of mesoventrite at midline on same plane as metaventrite, or on different plane than metaventrite. Mesoventral cavity moderately to very large and deep. Mesocoxa not conical and projecting. Mesocoxal cavities at middle narrowly separated, or moderately to widely separated. Mesocoxae separated by less than shortest diameter of coxal cavity, or more than shortest diameter of coxal cavity. Mesocoxal cavities circular to slightly transverse; not or slightly oblique. Mesoventrite separated by complete sutures from mesepisterna. Mesepisterna distinctly separated at midline; without deep pockets. Mesepimeron not visible from above. Mesocoxal cavities closed laterally; not partly closed by metepisterna. Mesoventral process absent or not extending to middle of mesocoxal cavity, or extending at least to middle of mesocoxal cavity. Mesometaventral junction a straight line, or a posteriorly curved, angulate or acute line.
Metaventral discrimen or median line moderately to very long. Paired postcoxal lines of metaventrite absent, or present. Postcoxal lines of metaventrite absent, or arched and strongly recurved. Metaventrite 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. Anterior edge of metaventrite without transverse carina between mesocoxal cavities. Exposed portion of metepisternum very long and narrow or absent. Metacoxae contiguous or narrowly separated; extending laterally to meet elytra or sides of body; completely separated from metaventrite by suture. Metacoxal plates well developed mesally, weak laterally, or weakly developed; not concealing most of basal abdominal ventrite. Metacoxae not greatly enlarged, or greatly enlarged; horizontally oriented. Lateral arms of metendosternite short or absent. Metendosternal laminae absent. Ventrolateral processes of metendosternite absent or weakly developed. Anterior process of metendosternite short or absent. Anterior tendons of metendosternite widely separated but not on lateral arms. 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; elongate. Inner posterior angle formed at base of radial cell right or obtuse. Radial cell not forming equilateral triangle. Ratio of length of apical area to total wing length 0.20–0.35. Medial bar of hind wing not crossed by fold. Free veins in medial area of hind wing 5 or 6, or 4. 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 absent. Anal lobe of hind wing absent, or present. Posterior edge of hind wing without fringe of long hairs.
Legs. Femoral attachment of mid trochanter strongly oblique with base of femur separate from coxa. Mesotrochanter not reduced or concealed from below. Metafemur not much wider than mesofemur, or much wider than mesofemur. Mesotibia not strongly widened, or strongly widened, widest at or near apex. Outer edge of mesotibia simple, crenulate or denticulate, or with distinct teeth or long spines. 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). Tarsomeres on hind leg at least as many as on mid leg. Tarsomeres on fore leg at least as many as on mid leg. Mesotarsomere 1 well developed and visible. Preapical mesotarsomeres together longer than apical one. Penultimate mesotarsomere not distinctly shorter than antepenultimate. Ventral mesotarsal lobes absent, or on penultimate tarsomere only. Mesotarsal claws paired; subequal in length and similar in form and angle of inclination; simple, or serrate, denticulate or pectinate. 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 four. 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. Ventrite 1 not much longer than 2. Abdominal process acute or narrowly rounded. Ventrite 5 in female without circular depression. Posterior edge of ventrite 5 not 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. Anterior edge of sternite 9 in male without median strut. Tergite 9 in male slightly to moderately emarginate, or deeply emarginate. Tergite 10 in male well developed and free.
Aedeagus trilobate; symmetrical. Anterior edge of tegmen or phallobase without struts. Parameres individually articulated to phallobase or base of penis; not outwardly hooked. Penis without dorsal and ventral lobes. Anterior edge of penis with paired struts.
Illustrations. • Paracardiophorus. Paracardiophorus venustus (Candèze). Locality: Australia. Artist: C. Eadie. Copyright CSIRO. Reference: Calder 1996.
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’.