Elateriformia (Coleoptera)

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

Neocrowsonia ? THROSCIDAE

Classification. Polyphaga: Elateriformia.

Distribution. Neocrowsonia viatoricus Kistner & Abdel-Galil is known only from the Cape Province of South Africa.

Biogeographic regions: Afrotropical.

Biology. Neocrowsonia adults have been collected in the nests of the termite Microhodotermes viator (Latreille); immature stages are unknown.

Notes. The head has a distinct median endocarina and the mandibles are perforate. The lobes on the tarsomeres are of an unusual type which are probably not homologous to those in Lissominae (Elateridae); there appear to be 3, not 2 on tarsomeres 1, 2 and 3, and 2 of the 3 are serrate.

References

Kistner, D. H. and F. A. Abdel-Galil 1986. A new genus and species of termitophilous Throscidae from South Africa (Coleoptera). Sociobiology 12: 305–313.

General appearance. Total length 1.8–2.5 mm. Ratio of body length to greatest body width 1.9–2.15. 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 glabrous or subglabrous, or 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 with median longitudinal groove or line (endocarina). Frontal region without median groove or line (endocarina). Head without ocelli.

Compound eyes absent.

Antennal insertions concealed from above; moderately to widely separated. Antennae not borne on raised tubercles. Antennal insertions countersunk so that they lie within saucer-like 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 deeply emarginate or excavate. 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 8, or 9. Antennae when posteriorly extended not reaching middle of prothorax. Antennae 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. First antennomere (scape) more than 3 times as long as 2nd (pedicel). Antenna not geniculate; without apical club, or with weak apical club. Antennal club with 6 or more segments; not 5-segmented or with 2nd segment subequal to or larger than 1st; compact; not lamellate; not or slightly serrate; not cupuliform; not or slightly flattened; not preceded by a cupule.

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. 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. Mandibular apex 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 with single tooth. 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 undivided or finely cleft, or indistinct or absent.

Prothorax. Ratio of pronotal length to greatest pronotal width 0.62–0.67. 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, or moderately to strongly, obliquely or vertically 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; 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 obtuse or right, or moderately to strongly acute; 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. 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, or with broad cavities. Prothoracic cavities absent, or external, open anteriorly, not visible from above. Prothoracic grooves absent. Prosternal process incomplete, or absent; narrowed apically; flat, concave, or only slightly elevated or curved behind coxae; not extending to 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 projecting well below prosternum. Procoxa without or with short concealed lateral extension. Procoxal cavity circular or longer than wide. Procoxal cavities at middle contiguous. 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 completely concealed or absent. Promesothoracic clicking mechanism absent.

Elytra. Elytra present. Ratio of elytral length to greatest elytral width 0.66–0.75. Ratio of elytral length to pronotal length 1.05–1.15. 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 at least 2 but less than 3, or 3 or more. Exposed abdominal segments more or less flexible. Elytral apices independently rounded or acute and separated by broad gap. Elytral suture not deflected near apex. Elytral apex without internal interlocking tongue. Epipleuron absent or incomplete; not or gradually narrowed. Lateral edge of elytron straight or weakly sinuate.

Pterothorax. Scutellum absent or not visible. Mesoscutum without stridulatory file. 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 not conical and projecting. Mesocoxal cavities at middle moderately to widely separated. Mesocoxae separated by more than shortest diameter of coxal cavity. Mesocoxal cavities circular to slightly transverse; not or slightly oblique. Mesoventrite partly or completely fused to mesepisterna. Mesepisterna without deep pockets. Mesepimeron not visible from above. Mesocoxal cavities open laterally; not partly closed by metepisterna. Mesometaventral junction absent due to fusion. Mesoventral and metaventral processes at midline solidly fused or separated at most by weakly impressed line. Accessory (mesal) mesocoxal articulation absent.

Metaventral discrimen or median line absent. Paired postcoxal lines of metaventrite absent. Postcoxal lines of metaventrite absent. Metaventrite not 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 contiguous or narrowly separated; separated by less than longest coxal diameter; not extending laterally to meet elytra or sides of body, or extending laterally to meet elytra or sides of body; at least partly fused to metaventrite, suture incomplete or absent. Metacoxal plates weakly developed; not concealing most of basal abdominal ventrite. Metacoxae not greatly enlarged; obliquely oriented. Lateral arms of metendosternite moderately to very long. Metendosternal laminae absent. Ventrolateral processes of metendosternite absent or weakly developed. Anterior process of metendosternite short or absent. Anterior tendons of metendosternite on lateral arms or not apparent. 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. 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 on more than one tarsomere. 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, or 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. 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 2. Number of basal ventrites connate none. 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 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. 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. 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 truncate. Tergite 10 in male well developed and free.

Aedeagus trilobate; symmetrical. Anterior edge of tegmen or phallobase without struts. Parameres partly or entirely fused together but articulated to phallobase; not outwardly hooked. Penis without dorsal and ventral lobes. Anterior edge of penis with paired struts.

Illustrations. • Neocrowsonia. Neocrowsonia viatorica Kistner & Abdel-Galil. Locality: Southern Africa. Photo: J. Green. 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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