Elateriformia (Coleoptera)

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

BRACHYPSECTRIDAE

Classification. Polyphaga: Elateriformia.

Distribution. The genus Brachypsectra occurs in the arid parts of southwestern North America, southern India, Malaysia and northern Australia.

Biogeographic regions: Nearctic, Oriental, Australian.

Biology. Brachypsectra adults are not commonly collected. The strongly flattened larvae are ambush predators, living under loose bark or stones and feeding on spiders and other small arthropods.

Notes. Brachypsectra has been placed within various elateriform superfamilies, but in most recent cladograms (Beutel 1995; Lawrence 1988, Lawrence et al. 1995), it appears to cluster with the cantharoid complex, the elateroid complex or both (Elateroidea in the sense of Lawrence 1988).

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.

Blair, K. G. 1930. Brachypsectra Lec. - the solution to an entomological enigma. Transactions of the Royal Entomological Society of London, 78: 45–50.

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.

Crowson, R. A. 1973. On a new superfamily Artematopoidea of polyphagan beetles, with the definition of two new fossil genera from the Baltic Amber. Journal of Natural History 7: 225–238.

Fleenor, S. B. and S. W. Taber 1999. Review of Brachypsectra with a new record of the Texas Beetle (B. fulva LeConte; Coleoptera: Brachypsectridae). Coleopterists Bulletin 53: 359–364.

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. 1991. Order Coleoptera (general discussion, family key, many family treatments), pp. 144–658. IN: F. W. Stehr (ed.), Immature Insects. Vol. 2. Kendall/Hunt Publishing Co., Dubuque, Iowa.

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.

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

Young, D. K. 2000. 59. Brachypsectridae. IN: R. H. Arnett, Jr., Jr. and M. C. Thomas (eds.), American Beetles. CRC Press, Gainesville, Florida (in press).

General appearance. Total length 4–7 mm. Ratio of body length to greatest body width 2.11–2.47. Body strongly flattened. 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; abruptly constricted posteriorly to form neck. Temples absent or not closely adpressed to prothorax; shorter than length of eye. 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 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. 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 concave to shallowly emarginate. 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 11. Antennae when posteriorly extended reaching beyond middle of prothorax but not middle of elytra. Antennae serrate, or pectinate or bipectinate, or incrassate or clavate. 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. 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 slightly transverse or subquadrate. Apex of labrum 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, or absent. Mandible short and broad. Mandibular apex not or slightly and gradually curved mesally, or moderately to strongly, 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. 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.

Prothorax. Ratio of pronotal length to greatest pronotal width 0.52–0.6. Prothorax widest at middle, or posteriorly. Sides of prothorax more or less straight, or 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 complete; 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; 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 located on posterior angles only. Pronotal disc without 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 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. 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 complete; narrowed apically; flat, concave, or only slightly elevated or curved behind coxae; slightly overlapping mesoventrite, or moderately to strongly overlapping mesoventrite. Apex of prosternal process 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 strongly transverse. Procoxal cavities at middle narrowly separated, or moderately to widely separated. Procoxal cavities externally open; broadly open. Postcoxal projection absent or very short. Procoxal cavities with narrow lateral extensions. Procoxal cavities internally open. Prothoracic trochantin or pleurotrochantin at least partly exposed, or completely concealed or absent. Promesothoracic clicking mechanism absent.

Elytra. Elytra present. Ratio of elytral length to greatest elytral width 1.69–2. Ratio of elytral length to pronotal length 4–4.25. 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 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; posteriorly broadly rounded or obtusely angulate. Mesoscutum without stridulatory file. Mesoventrite 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. Mesoventral cavity moderately to very large and deep. Mesocoxa not conical and projecting. Mesocoxal cavities at middle narrowly separated. Mesocoxae separated by less than shortest diameter of coxal cavity. 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 complex fitting. 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. 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 moderately elongate, or very long and narrow or absent. 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; 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 absent or weakly developed. Anterior process of metendosternite moderately long. 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 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 less than 0.2. 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. 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 transverse or slightly oblique. 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. Inner apical angle of mesotibia not or slightly produced, without tooth. Mesotibial spurs glabrous or absent; 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. 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 present and exposed; absent or with 2 or fewer setae. Outer edge of protibia simple and rounded to carinate but without lobes or teeth, except at apex. 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 none. Abdominal sternite 2 apparently absent. 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. 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 present. 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 without median strut. Pygidium (sclerotized tergite 7 or 8) more or less horizontal. Anterior edge of sternite 9 in male without median strut. Tergite 9 in male 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. • Brachypsectra. Brachypsectra fulva LeConte. Locality: North America. Artist: E. Van Tassell. Courtesy of Dr. Ross Arnett. Reference: Arnett 1963.


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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