Elateriformia (Coleoptera)

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

Duliticolinae (larviform females) LYCIDAE

Classification. Polyphaga: Elateriformia.

Distribution. Species of Duliticola and Platerodrilus are known from India, Southeast Asia and the East Indies.

Biogeographic regions: Oriental.

Biology. Larvae and larviform females of Duliticola species are well known inhabitants of tropical forests, where they usually occur on the surfaces of logs. Their peculiar form has earned them the name "trilobite larvae". Their feeding habits, like those of most Lycidae, are uncertain; however they appear to suck juices from rotting plant material.

References

Crowson, R. A. 1972. A review of the classification of Cantharoidea (Coleoptera), with the definition of two new families, Cneoglossidae and Omethidae. Revista de la Universidad de Madrid 21(82): 35–77.

Mjöberg, E. 1925. The mystery of the so called "trilobite larvae" or "Perty's larvae" definitely solved. Psyche 32: 119–154, pls. 3–4.

Wong, A. T. C. 1996. A new species of neotenous beetle, Duliticola hoiseni (Insecta: Coleoptera: Cantharoidea: Lycidae) from Peninsular Malaysia and Singapore. Raffles Bulletin of Zoology 44: 173–187.

General appearance. Total length 40–80 mm. Ratio of body length to greatest body width 2.05–3.15. Body strongly flattened. Sides of body not evenly curved. Body not capable of conglobation (rolling into a ball). Upper surfaces of body glabrous or subglabrous. 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) greater than 1. Head width just behind eyes not distinctly greater than prothoracic width. Head not or slightly declined; 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. 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). Frontal region without median groove or line (endocarina). Head without ocelli.

Compound eyes absent.

Antennal insertions exposed from above; narrowly 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 absent or incomplete. Clypeus not laterally emarginate. Anterior edge of clypeus or clypeolabrum straight to convex. Mouth cavity anteriorly or anteroventrally oriented. Pregular area without laterally opening cavities. Head ventrally without paired subgenal ridges. Head without anteriorly-projecting genal processes. Gular sutures widely separated or absent. Corporotentorium incomplete or absent. Cervical sclerites present.

Antennae. Number of antennomeres 2. Antennae when posteriorly extended not reaching middle of prothorax. Antennae moniliform, or of a unique configuration, none of above. Antennomeres 3, 4 or 5 to 10 without or with single rami (uniramose). Antennae entirely subglabrous and without obvious modifications. First antennomere (scape) less than 3 times as long as 2nd (pedicel). Antenna not geniculate; without apical club.

Mouthparts. Labrum concealed beneath clypeus or apparently absent; partly or completely fused to clypeus or frontoclypeus, without or with incomplete suture. Mouthparts not forming a piercing or sucking tube. Mandibles present. Mandible very narrow and elongate. Mandibular apex not or slightly and gradually curved mesally; unidentate, truncate or rounded; subacute, bidentate or multidentate. Dorsal part of mandible without tubercle; without setose cavity. Mandible moderately to strongly, more or less evenly sclerotized or pigmented; visible in lateral view. Incisor edge of mandible simple. Mandible without mola; without prostheca. Inner basal angle of mandible without pubescent process. Maxilla with single apical lobe. Maxillary lobe(s) not stylet-like. Apex of galea or maxillary lobe without or with few setae or spines; without heavily sclerotized teeth or hooks. 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 indistinct or absent.

Prothorax. Ratio of pronotal length to greatest pronotal width 0.55–0.68. Prothorax widest posteriorly. Sides of prothorax more or less straight. Prothorax not laterally compressed to form cavities for legs. Sides of prothorax moderately to strongly, horizontally explanate. Lateral pronotal carinae complete; simple; visible for their entire lengths 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; absent, right or rounded, not produced. 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. Discal carinae of pronotum absent. Pronotal disc without paired basal impressions. Pronotum without median longitudinal groove or line, or with median longitudinal groove or line. Anterior edge of pronotum simple, without margin. Hypomeron without pit.

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. Prosternum in front of coxae without paired lines or carinae. Anterior edge of prosternum without margin; without mesal excavation. Anterolateral or ventrolateral portions of prothorax without cavities or grooves. Prothoracic cavities absent. Prothoracic grooves absent. Prosternal process incomplete. 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 projecting well below prosternum. Procoxa without or with short concealed lateral extension. Procoxal cavities absent, procoxae attached externally. Postcoxal projection absent or very short. Prothoracic trochantin or pleurotrochantin completely concealed or absent. Promesothoracic clicking mechanism absent.

Elytra. Elytra absent (anelytrous or larviform). Lateral edge of elytron straight or weakly sinuate.

Pterothorax. Mesoventrite without 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. Mesoventral cavity absent. Mesocoxa conical and projecting. Mesocoxal cavities absent, mesocoxae attached externally. Mesoventrite separated by complete sutures from mesepisterna. Mesepisterna distinctly separated at midline; without deep pockets. Mesepimeron not visible from above.

Metaventral discrimen or median line absent. Paired postcoxal lines of metaventrite absent. Postcoxal lines of metaventrite absent. Metaventrite longer than first abdominal ventrite. Postcoxal pits of metaventrite absent. Metaventrite flat to slightly 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 widely separated; not extending laterally to meet elytra or sides of body; completely separated from metaventrite by suture. Metacoxal plates absent. Metacoxae not greatly enlarged; horizontally oriented. Apical portion of metendosternite not or only slightly emarginate.

Hind wing. Hind wing highly reduced or absent.

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. 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 2 or fewer tarsomeres. Tarsomeres on hind leg at least as many as on mid leg. Tarsomeres on fore leg at least as many as on mid leg. Ventral mesotarsal lobes absent. Mesotarsal claws single; simple. Appendage on each tarsal claw absent. Mesotarsal claws without setae near base. 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 10. Number of basal ventrites connate none. Abdominal sternite 2 visible. 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 absent. 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.

Parameres not outwardly hooked.

Illustrations. • Duliticola. Duliticola hoiseni Wong. Locality: Malaysia. Photo: A. T. C. Wong. Reference: Wong 1996. Courtesy of the Raffles Bulletin of Zoology.


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’.

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