Elateriformia (Coleoptera)

DELTA
Home

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

HETEROCERIDAE

Classification. Polyphaga: Elateriformia.

Distribution. Heterocerinae are common in most regions of the world, but Elythomerus elongatulus Waterhouse (Elythomerinae) is known only from the Rockhampton area in Queensland.

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

Biology. Adult and larval Heteroceridae construct tunnels in wet sand at the edges of streams and ponds and feed on algae. Adults are often attracted to lights at night.

References

Charpentier, R. 1965. A monograph of the family Heteroceridae (Coleoptera) of the Ethiopian region, pp. 215–343. IN: B. Hanström, P. Brinck and G. Rudebeck (eds.), South African Animal Life. Results of the Lund University Expedition in 1950–1951. Vol. XI. Almqvist and Wiksell, Stockholm.

Charpentier, R. 1968. A monograph of the family Heteroceridae (Coleoptera) of the Notogean region. Arkiv för Zoologi, (2) 20: 205–241.

Drechsel, U. 1979. 44. Familie: Heteroceridae, pp. 296–304. IN: H. Freude, K. W. Harde and G. A. Lohse (eds.), Die Käfer Mitteleuropas. Band 6. Diversicornia. Goecke & Evers, Krefeld.

Lawrence, J. F. 1991. Heteroceridae (Dryopoidea), pp. 402–404. IN: F. W. Stehr (ed.), Immature Insects. Vol. 2. Kendall/Hunt Publishing Co., Dubuque, Iowa.

Mascagni, A. 1995. Heteroceridae: Check list of the Heteroceridae of China and neighboring countries, and descriptions of two new species, pp. 341–349. IN: M. A. Jäch and L. Ji (eds.), Water Beetles of China. Vol. I. Zoologisch-Botanische Gesellschaft in Österreich und Wiener Coleopterologenverein, Vienna.

Pacheco M., F. 1964. Sistemática, Filogenia y Distribución de los Heterocéridos de América (Coleoptera: Heteroceridae). Escuela Nacional de Agricultura, Colegio de Post-Graduados, Chapingo, México. xii + 155 pp., 55 pls.

Thomas, M. C. 2000. 51. Heteroceridae. IN: R. H. Arnett, Jr., Jr. and M. C. Thomas (eds.), American Beetles. CRC Press, Gainesville, Florida (in press).

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

General appearance. Total length 1–8 mm. Ratio of body length to greatest body width 1.7–3.05. Body slightly flattened to moderately 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; 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. Frontal region not to moderately, gradually declined. 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. 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 exposed from above; moderately to widely separated. Antennae not borne on raised tubercles. Antennal insertions flush with head capsule or raised, not in fossae. Subantennal groove or cavity on head absent or very weakly developed. Frontoclypeal suture distinctly impressed; straight, slightly curved or angulate. Clypeus not laterally emarginate. Anterior edge of clypeus or clypeolabrum straight to convex, or concave to shallowly emarginate. Mouth cavity anteriorly or anteroventrally 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 9, or 10, or 11. Antennae when posteriorly extended not reaching middle of prothorax. Antennae pectinate or bipectinate, 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 4, or antennomere 5, or antennomere 5 or beyond. First antennomere (scape) less than 3 times as long as 2nd (pedicel), or more than 3 times as long as 2nd (pedicel). Antenna not geniculate; without apical club, or with weak apical club, or with strong apical club. Antennal club 1-segmented, or with 6 or more segments; not 5-segmented or with 2nd segment subequal to or larger than 1st; loose, or compact; not lamellate; not or slightly serrate; not or slightly flattened, or distinctly flattened; not preceded by a cupule, or preceded by a cupule.

Mouthparts. Labrum at least partly visible; free, membranous or separated by suture. Major portion of labrum slightly transverse or subquadrate, or distinctly longer than wide. 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 moderately elongate. Mandibular apex moderately to strongly, gradually curved mesally; unidentate, truncate or rounded, or bidentate or bilobed. Dorsal part of mandible without tubercle, or with tubercle fitting into cavity on clypeus; 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, or with reduced prostheca. Prostheca absent or without articulated, sclerotized process. Inner basal angle of mandible without pubescent 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; at least as wide as or longer than preapical one. Maxillary palp without complex palp organ. Apical labial palpomere cylindrical to fusiform. Ligula undivided or finely cleft, or deeply emarginate or bilobed.

Prothorax. Ratio of pronotal length to greatest pronotal width 0.52–0.82. Prothorax widest at middle. Sides of prothorax moderately to strongly curved. 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. 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 broadly rounded or obtusely angulate. Posterior angles of pronotum absent or broadly rounded, or obtuse or right; not produced and acute. Posterior edge of pronotum more or less straight or evenly rounded; simple; not or vaguely margined, or with narrow raised margin or bead. Discal carinae of pronotum absent. Pronotal disc without 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 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; gradually expanded or narrowed and then expanded, or gradually expanded and then narrowed; flat, concave, or only slightly elevated or curved behind coxae, or strongly elevated and curved dorsally behind coxae; slightly overlapping mesoventrite, or 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, or projecting well below prosternum. Procoxa without or with short concealed lateral extension. Procoxal cavities present, procoxae countersunk. Procoxal cavity strongly transverse. Procoxal cavities at middle narrowly 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 1.18–2.3. Ratio of elytral length to pronotal length 2.2–3.53. 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, or crenulate; posteriorly narrowly rounded or acute, or broadly rounded or obtusely angulate. Mesoscutum without stridulatory file. Mesoventrite without paired procoxal rests, or with paired procoxal rests. Paired mesoventral procoxal rests absent, horizontal or slightly oblique, or moderately to strongly 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 absent, or small and shallow, or moderately large and shallow. Mesocoxa not conical and projecting. Mesocoxal cavities present, mesocoxae countersunk. 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 open 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 an anteriorly 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 but not or slightly 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 present. Anterior edge of metaventrite without transverse carina between mesocoxal cavities. Exposed portion of metepisternum moderately elongate. Metacoxae contiguous or narrowly separated; separated by less than longest coxal diameter; 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 weakly developed; not concealing most of basal abdominal ventrite. Metacoxae not greatly enlarged; horizontally oriented, or obliquely 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; with normal transverse folds. Radial cell of hind wing highly reduced or absent; incomplete or absent. Radial cell not forming equilateral triangle. Ratio of length of apical area to total wing length 0.20–0.35, or 0.36–0.5, or greater than 0.5. Apical area of hind wing without veins or sclerotizations. Medial bar of hind wing not crossed by fold. Free veins in medial area of hind wing 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 absent. Anal lobe of hind wing absent. 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. Mesotibia not strongly widened, or strongly widened, widest at or near apex, or strongly widened, widest well before apex. Outer edge of mesotibia 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; double. Mesotarsus 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. Mesotarsomere 1 well developed and visible. Preapical mesotarsomeres together longer than apical one. Penultimate mesotarsomere not distinctly shorter than antepenultimate. Ventral mesotarsal lobes absent. 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. Metatibial spurs double.

Abdomen. Number of abdominal ventrites 5. Number of basal ventrites connate three. 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. 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, 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 unclassified; symmetrical, or asymmetrical. Anterior edge of tegmen or phallobase without struts. Parameres fused to phallobase or base of penis but free from one another, or partly or entirely fused together and to phallobase, or absent; not outwardly hooked. Penis without dorsal and ventral lobes. Anterior edge of penis without struts, or with paired struts.

Illustrations. • Elythomerus. Elythomerus elongatulus Waterhouse. Locality: Australia. After Charpentier 1968. • Heterocerus. Heterocerus flindersi Blackburn. Locality: Australia. Artist: F. Nanninga. Copyright CSIRO. Reference: Britton 1970. • Micilus. Micilus murinus (Kiesenwetter). Locality: Europe. Reference: Reitter 1911.


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’.

Contents