Elateriformia (Coleoptera)

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

CHELONARIIDAE

Classification. Polyphaga: Elateriformia.

Distribution. Brounia thoracica Sharp is restricted to New Zealand. Species of Chelonarium throughout the warmer parts of the world but are more common in the New World tropics. Pseudochelonarium species occur throughout eastern Asia and the East Indies and as far south as New Guinea.

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

Biology. Chelonarium larvae have been found in leaf litter, debris at the bases of orchids, epiphytic ant plants, nests of mound-building ants, army ant refuse heaps, and dead branches, and occasionally under bark.

Notes. Most phylogenetic studies of Elateriformia (Lawrence 1988, Beutel 1995, Lawrence et al. 1995, Costa et al. 1999), suggest that this family is closely related to Ptilodactylidae and Psephenidae. Although Brounia was included in Ptilodactylidae by Crowson (1981) and Lawrence (1988), based in part on a misidentified larva, detailed examination of adult legs, wings and male genitalia leave little doubt that the genus belongs in Chelonariidae.

References

Beutel, R. G. 1995. Phylogenetic analysis of Elateriformia (Coleoptera: Polyphaga) based on larval characters. Journal of Zoological Systematics and Evolutionary Research 33: 145–171.

Costa, C., S. A. Vanin and S. Ide 1999. Systematics and bionomics of Cneoglossidae with a cladistic analysis of Byrrhoidea sensu Lawrence & Newton (1995) (Coleoptera, Elateriformia). Arquivos de Zoologia 35: 231–300.

Crowson, R. A. 1981. The Biology of the Coleoptera. Academic Press, London, xii + 802 pp.

Dalla Torre, E. von 1911. Pars 33. Nosodendridae, Byrrhidae, Dermestidae. IN: S. Schenkling (ed.), Coleopterorum Catalogus. W. Junk, Berlin, 96 pp.

Ivie, M. A. 2000. 55. Chelonariidae. IN: R. H. Arnett, Jr., Jr. and M. C. Thomas (eds.), American Beetles. CRC Press, Gainesville, Florida (in press).

Janzen, D. H. 1974. Epiphytic myrmecophytes in Sarawak: mutualism through the feeding of plants by ants. Biotropica 6: 237–259.

Lawrence, J. F. 1988. Rhinorhipidae, a new beetle family from Australia, with comments on the phylogeny of the Elateriformia. Invertebrate Taxonomy 2: 1–53.

Lawrence, J. F., N. B. Nikitsky and A. G. Kirejtshuk 1995. Phylogenetic position of Decliniidae (Coleoptera: Scirtoidea) and comments on the classification of Elateriformia (sensu lato), pp. 375–410. IN: J. Pakaluk and S. A. Slipinski (eds.), Biology, Phylogeny, and Classification of Coleoptera: Papers Celebrating the 80th Birthday of Roy A. Crowson. Muzeum i Instytut Zoologii Polska Akademia Nauk, Warsaw.

Mequignon, A. 1934. Les Chelonarium de l'Amerique continentale. Annales de la Société Entomologique de France, 103: 199–256.

Méquignon, A. 1935. Notes sur le genre Pseudochelonarium, Pic (Col. Dryopidae). Stylops 4 (3): 66–68.

Paulus, H. F. 1969. Pseudochelonarium (Neochelonarium) kalimantanense n. sp. aus Borneo, mit Bemerkungen zum System der Chelonariidae (Col. Dryopoidea). Zeitschrift der Arbeitsgemeinschaft Österreichen Entomologen 21: 105–109.

Sharp, D. 1878. New Coleoptera from New Zealand. Entomologist's Monthly Magazine 15: 47–52, 81–83.

Spangler, P. J. 1991. Chelonariidae (Dryopoidea), pp. 394–395. IN: F. W. Stehr (ed.), Immature Insects. Vol. 2. Kendall/Hunt Publishing Co., Dubuque, Iowa.

General appearance. Total length 3–8.5 mm. Ratio of body length to greatest body width 1.63–2.4. 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, or including stiff, erect, dark bristles; not including scales or scale-like setae, or 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 moderately to strongly declined; not entirely concealed from above by pronotum, or 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 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 present. Eyes strongly 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; narrowly separated, or closely approximate or contiguous. 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 narrow, or incomplete or absent; 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, or pectinate or bipectinate. 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, or antennomere 5. 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. 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, or slightly concave or emarginate. Labrum mostly membranous or very lightly sclerotized. Mouthparts not forming a piercing or sucking tube. Mandibles present. Mandible short and broad. Mandibular apex not or slightly and gradually curved mesally, or moderately to strongly, gradually curved mesally; unidentate, truncate or rounded; rounded or truncate. Dorsal part of mandible without tubercle; without setose cavity. Mandible much more lightly sclerotized or pigmented at apex; enclosed in mouth cavity or not visible in lateral view. Incisor edge of mandible simple. Mandible without mola; without 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 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 slightly to strongly expanded apically. Ligula deeply emarginate or bilobed.

Prothorax. Ratio of pronotal length to greatest pronotal width 0.45–0.72. Prothorax widest 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, or absent; 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; absent, right or rounded, not produced. Posterior angles of pronotum obtuse or right, or moderately to strongly acute; not produced and acute. Posterior edge of pronotum more or less straight or evenly rounded, or moderately to strongly produced forming mesal lobe; distinctly crenulate; 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. Anterior edge of pronotum simple, without margin. Hypomeron without pit.

Anterior portion of prosternum at midline shorter 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. Anterior edge of prosternum not produced anteriorly. Prosternum in front of coxae concave or biconcave, or flat to moderately convex, or strongly convex without carina. Prosternum in front of coxae without paired lines or carinae. Anterior edge of prosternum without margin; with mesal excavation. Anterolateral or ventrolateral portions of prothorax without cavities or grooves. Prothoracic cavities absent. Prothoracic grooves absent. Prosternal process complete; parallel-sided; flat, concave, or only slightly elevated or curved 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, or slightly 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 1.27–1.82. Ratio of elytral length to pronotal length 3.07–4.25. 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 complete; not or gradually narrowed. Lateral edge of elytron straight or weakly sinuate.

Pterothorax. Scutellum well developed; abruptly elevated; anteriorly simple, or crenulate; 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, or on different plane than metaventrite. Mesoventral cavity moderately to very large and deep. 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. 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 extending at least to middle of mesocoxal cavity. Mesometaventral junction a posteriorly curved, angulate or acute line, or an anteriorly curved, angulate or acute line. Mesoventral and metaventral processes at midline separated by gap, groove, or suture. Accessory (mesal) mesocoxal articulation absent.

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 moderately to strongly convex. Transverse groove of metaventrite absent. 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; not concealing most of basal abdominal ventrite. Metacoxae not greatly enlarged; horizontally oriented. Lateral arms of metendosternite short or absent, or moderately to very long. Metendosternal laminae absent. Ventrolateral processes of metendosternite strongly developed. Anterior process of metendosternite moderately long, or short or absent. Anterior tendons of metendosternite moderately or very close together. Apical portion of metendosternite not or only slightly emarginate.

Hind wing. Hind wing well developed; with normal transverse folds. Radial cell of hind wing well developed; elongate. 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 0.20–0.35, or 0.36–0.5. Apical area of hind wing with one or more vague sclerotizations or pigment patches. 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 reduced, or absent. Apex of wedge cell of hind wing obliquely truncate. 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 well before apex. 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. Inner apical angle of mesotibia not or slightly produced, without tooth. Mesotibial spurs glabrous or absent; absent. Mesotarsus with 5 distinct tarsomeres (pentamerous), or with 4 distinct tarsomeres and reduced penultimate one (pseudotetramerous). 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, or shorter than apical one. Penultimate mesotarsomere distinctly shorter than antepenultimate. Ventral mesotarsal lobes on antepenultimate tarsomere only, or on more than one tarsomere. Mesotarsal claws paired; subequal in length and similar in form and angle of inclination; simple, or toothed or bifid. Appendage on each tarsal claw absent. Mesotarsal claws without setae near base. Mesotarsal empodium absent or concealed; absent or with 2 or fewer setae. Outer edge of protibia simple and rounded to carinate but without lobes or teeth, except at apex, or with one or more distinct lobes or teeth. Outer apical angle of protibia simple or slightly produced, without lobe, teeth or spines. Inner subapical edge of protibia without antenna cleaner. Protibial spurs absent. Hind legs without swimming hairs. Preapical surfaces of metatibia without ridges or combs. Metatibial articular area not to only moderately expanded, narrowly oval or oblique. Metatibial spurs absent.

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, or broadly rounded or angulate. 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. Tergite and sternite 7 separated by membrane or distinct suture. Subapical abdominal luminous organ absent. Ventrites without setose patches or foveae. Functional spiracles on abdominal segment 8 absent. Functional spiracles on abdominal segment 7 present. Functional spiracles on abdominal segment 6 present. Functional spiracles on abdominal segment 5 present. 7th abdominal spiracles located in pleural membrane. 6th abdominal spiracles located in pleural membrane. 5th abdominal spiracles located in pleural membrane. Anterior edge of sternite 8 in male with median strut. Pygidium (sclerotized tergite 7 or 8) more or less horizontal. Anterior edge of sternite 9 in male without median strut, or with median strut (spiculum gastrale). Tergite 9 in male deeply emarginate, or almost completely divided into two parts. Tergite 10 in male well developed and free.

Aedeagus trilobate; symmetrical, or asymmetrical. 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, or with dorsal and ventral lobes. Anterior edge of penis without struts, or with paired struts.

Illustrations. • Brounia. Brounia thoracica Sharp. Locality: New Zealand. Artist: D. Helmore. Courtesy of Landcare Research New Zealand Ltd. Reference: Klimaszewski and Watt 1997. • Chelonarium. Chelonarium australicum Lea. Locality: Australia. Artist: S. P. Kim. Copyright CSIRO. Reference: Lawrence and Britton 1991. • Pseudochelonarium. Pseudochelonarium sp. Locality: Japan. 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’.

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