Classification. Polyphaga: Elateriformia.
Distribution. Pterotus obscuripennis LeConte occurs from western Washington and Oregon to northern Baja California; P. curticornis Chemsak is known from Riverise Co. in southern California.
Biogeographic regions: Nearctic.
Biology. Larval Pterotus feed primarily on slugs, while adults may not feed.
Chemsak, J. A. 1978. A new species of Pterotus LeConte from California (Coleoptera: Lampyridae). Pan-Pacific Entomologist 54: 157–158.
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.
Dean, M. B. 1979. The Natural History of Pterotus obscuripennis LeConte (Lampyridae, Coleoptera). Humboldt State University (Master of Arts Thesis), Eureka, California, 94 pp.
Fender, K. M. 1962. Family Lampyridae, pp. 35–43. IN: M. H. Hatch, The Beetles of the Pacific Northwest. Part III: Pselaphidae and Diversicornia I. University of Washington Publications Press, Seattle (University of Washington Publications in Biology, Vol. 16), 503 pp.
LeConte, J. L. 1859. Catalogue of the Coleoptera of Fort Tejon, California. Proceedings of the Academy of Natural Science of Philadelphia 11: 69–90.
Lloyd, J. E. 2000. 70. Lampyridae. IN: R. H. Arnett, Jr., Jr. and M. C. Thomas (eds.), American Beetles. CRC Press, Gainesville, Florida (in press).
McDermott, F. A. 1966. Pars 9 (Editio secunda). Lampyridae. IN: W. O. Steel (ed.), Coleopterorum Catalogus Supplementa. W. Junk, The Hague, 149 pp.
Pic, M. 1927. Pars 94. Phengodidae, Karumiidae. IN: S. Schenkling (ed.), Coleopterorum Catalogus. W. Junk, Berlin, 8 pp.
General appearance. Total length 25–35 mm. Ratio of body length to greatest body width 4.85–5.45. 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. 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. Head without ocelli.
Compound eyes present. Eyes not or only slightly protuberant. Eyes finely facetted; without interfacetal setae. 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. 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 absent.
Antennae. Number of antennomeres 6. Antennae when posteriorly extended not reaching middle of prothorax. Antennae filiform, or moniliform. 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) less than 3 times as long as 2nd (pedicel). Antenna not geniculate; without apical club.
Mouthparts. Labrum concealed beneath clypeus or apparently absent. Mouthparts not forming a piercing or sucking tube. Mandibles present. Mandible very narrow and elongate. Mandibular apex moderately to strongly, gradually curved mesally; unidentate, truncate or rounded. Dorsal part of mandible without tubercle; without setose cavity. Incisor edge of mandible simple. Mandible without mola; without prostheca. Maxilla with single apical lobe. Maxillary lobe(s) not stylet-like. Apex of galea or maxillary lobe densely setose or spinose; 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.
Prothorax. Ratio of pronotal length to greatest pronotal width 0.7–0.78. Prothorax widest posteriorly. Sides of prothorax more or less straight. 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, or absent; 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; 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 with median longitudinal groove or line. 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. Prosternum in front of coxae flat to moderately convex. 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 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. Promesothoracic clicking mechanism absent.
Elytra. Elytra absent (anelytrous or larviform). Lateral edge of elytron straight or weakly sinuate.
Pterothorax. Scutellum absent or not visible. 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. Metacoxae widely separated; 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 3 distinct tarsomeres (trimerous). 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 shorter 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.
Abdomen. Number of abdominal ventrites 8, or 9. 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 present. Ventrites without setose patches or foveae. Functional spiracles on abdominal segment 8 present.
Parameres not outwardly hooked.
Illustrations. • Pterotus. Pterotus obscuripennis LeConte. Locality: California. Artist: M. B. Dean. Courtesy of Michael B. Dean. Reference: Dean 1979.
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’.