Glyptotus cribratus LeConte

Steiner, Warren E., 2014, Larvae and pupae of two North American darkling beetles (Coleoptera, Tenebrionidae, Stenochiinae), Glyptotus cribratus LeConte and Cibdelis blaschkei Mannerheim, with notes on ecological and behavioural similarities, ZooKeys 415, pp. 311-327 : 311-317

Glyptotus cribratus LeConte

Background.

A single larva from southern Florida, USA, presumed to be Glyptotus cribratus , was reported by St. George (1924), who provided some key characters though the specimen’s identity has remained uncertain. New associated adult and larval material, including one larva reared to an adult and another providing the first known pupal specimen (described herein), shows that the larva from St. George’s account was not that of Glyptotus , as discussed below. The specimen, presumably in USNM, could not be located.

Three mature larvae, found in wood products from Mexico, 1982-84, were identified as " Glyptotus sp." by T. J. Spilman, but it is uncertain what material he used to make this determination; these larvae are considered in the present study to be Glyptotus cribratus , identical to specimens from USA; the species is known from southern Texas and thus its occurrence in north-eastern Mexico is feasible.

Description of mature larva.

(Figs 1, 3-5, 9-12).

Body. Length 23-30 mm; elongate-cylindrical, pale yellowish-white with light brown dorsal bands at posterior edges of terga and anterior edge of prothoracic tergum; mandible apices and bases, claws of tarsunguli, and apices of urogomphi and associated processes blackish to brown, heavily sclerotized; cuticle otherwise lightly sclerotized, surfaces shining, finely rugose, with scattered fine setae; abdominal tergum VIII slightly darker yellow-brown with scattered large circular punctures.

Head. Prognathous, head slightly declined, globular but slightly flattened dorsoventrally. Head capsule width 3.4-3.5 mm. Epicranial stem about one fifth head capsule length; frontal arms widely V-shaped, fine and obscure. Each half of head capsule with 10-13 scattered, long erect setae positioned dorsally and laterally. Stemmata five on each side closely posterior to antenna base, variably pigmented; anterior row of three closely spaced and usually darker than offset pair behind them. Clypeus convex, transverse, weakly trapezoidal, about two times wider than long, with one long seta on each side of disc and three smaller setae at lateral edges. Labrum transverse, convex, with two long discal setae, two anterior setae near midline, and four smaller, fine setae along each side of anterior edge. Epipharynx with three relatively stout setae along each side of anterior margin and two very short, stout medial spines, the pair slightly offset to left; with a cluster of 8-9 small round sensory papillae anterior to spines; tormae slightly asymmetrical. Antenna three segmented with membranous base globular, wider than long; first segment longest, cylindrical, wider toward apex, 2.5 × longer than wide; second segment ovoid, two thirds as long as first, 2 × longer than wide, with apical sensoria flat, kidney-shaped, partly encircling base of third segment; third segment very small, cylindrical, 1.5 × longer than wide, with a single fine seta apically. Mandibles asymmetrical, apices tridentate, left mandible with a fourth feeble tooth dorsally along sharp incisor edge; left mola concave, with a prominent premolar tooth and three transverse, sclerotized ridges; right mola convex, with a transverse fossa surrounded by irregularly prominent ridges. Ligula with four fine apical setae; prementum, mentum, submentum each with a pair of long setae near base. Hypopharyngeal sclerome well developed, tridentate, with smooth concavity in middle; median tooth carinate, with Y-shaped arms to prominent, conical, lateral teeth; basal transverse ridge asymmetrical.

Thorax. Prothorax as long as wide; meso- and metathorax wider than long; terga with 9-12 fine setae on each side, more closely spaced laterally. Mesothoracic spiracle simple, ovate, slightly larger and narrower than abdominal spiracles; metathoracic spiracle visible, very small, nearly circular. Prothoracic leg slightly larger than mid- and hindlegs; all legs with trochanter elongated, with anterior and posterior rows of setae on ridges; femur and tibia bearing scattered, shorter setae; tarsungulus with two pre-basal setae; claw simple, sharp, curved apically, two thirds the length of tarsungulus.

Abdomen. Abdominal segments I-VII similar, nearly as long as wide, gradually slightly wider posteriorly; terga with sparse setae as on thoracic terga; spiracles annular, broadly ovate; sterna on each side with an anterior group of 4-5 setae of varying sizes and a pair of setae posteriorly. Tergum VII with a field of circular, deep punctures across anterior two thirds of middle. Tergum VIII as long as wide, abruptly narrowing posteriorly, with an extensive field of large, deep, circular punctures across anterior half and expanding on sides and dorsally with 7-8 scattered fine setae on each side; sloped posterior bearing two somewhat sclerotized, umbonate bullae on each side, large lateral one with a long seta arising from anterior of base of umbo; small umbo posterior to larger one and closer to midline, connected to larger by a feeble ridge, the four bullae forming a trapezoidal arrangement in posterior view, immediately anterior to a broad membranous apical area which opposes a similar dorsal membrane at anterior of tergum IX. Tergum IX short, about two thirds the width of tergum VIII and hinged to it, allowing curved urogomphi to come forward to oppose and contact bullae of tergum VIII; lateral hinge joint with a sclerotized, tooth-like, anterior process; urogomphi long, gradually tapered, divergent and curved dorsally with sharp apices pointing anteriorly, nearly round in cross-section, darkly sclerotized in apical half, each with three other sclerotized, tooth-like projections near base, as follows: large lateral claw-like process with apex pointed upward, forward and angled laterally, with a single dorsal seta below apex; small dorsal cone-like process bearing a single seta near apex; smaller, mesal, short, pointed to button-like process closely opposing other on opposite urogomphus. Other setae on tergum IX long, scattered; urogomphus with three setae on ventral (posterior) side; hinge process with a single seta near base; lateral and ventral surface with 7-8 scattered setae. Abdominal segment X small, ventral, transverse, semi-circular, convex, 3 × wider than long, with a row of six fine setae across width; pygopods absent.

Description of pupa.

(Figs 17-20, 25, 27).

Body. Length (from anterior edge of pronotum to tips of urogomphi) 15.1 mm, width of pronotum 3.9 mm; body color white with brownish surface setae, apices of urogomphi and spines on lateral processes; body very sparsely setose except pronotum with numerous fine discal and marginal setae, more dense anteriorly. Lateral processes of middle abdominal segments well developed, wing-like, bearing anterior and posterior smooth teeth and two smaller setigerous lateral spines between them; urogomphi long, smooth, gradually tapered to divergent, upturned apices.

Head. Hypognathous; surface smooth but with transverse wrinkles across frons; projection above antennal insertion rounded, not prominent; a few fine setae on frons, near eye, on clypeus and labrum; single seta on left mandible, near middle on outer curve; row of four setae on right mandible, from base to near middle on outer curve; single very small seta on outer edge of maxillary palpus, at base of last segment.

Thorax. Pronotum broadly shield-shaped, slightly wider than long, smooth with subtle transverse wrinkles; anterior angles and apex broadly rounded, posterior margin narrowly sinuate with posterior angles slightly pointed posteriorly. Pronotal surfaces with many short, fine setae except anterior margin and part of disc bare and setae more sparse in posterior part of disc; setae most closely spaced along margin of anterior angle, with some setae 2 × longer than adjacent ones, fine and often curved; hypomeron smooth, with a few widely spaced fine setae; meso- and metatergite transverse, smooth, with very few fine setae; mesonotum produced and elevated posteriorly at middle (scutellar umbo); metanotum about 2 × longer mesonotum, nearly 2 × longer than abdominal tergite 1. Elytral sheath smooth with broad, shallow wrinkles; metathoracic wing sheath slightly shorter apically; meso- and metaventrite smooth. Legs and tarsi smooth, with a few scattered fine setae; femora with 5-7 setae from mid-length to near apex; tibiae with 3-5 setae along mid-length; protarsi with 3-4 setae on apical tarsomeres ventrally and laterally; apical tarsomeres of meso-and metatarsi with 1-2 setae laterally.

Abdomen. All surfaces smooth, bearing scattered fine setae; spiracles annular, vertically ovate to reniform, barely pigmented, visible on segments 2-6. Tergite 1 short, with five discal setae on each side, lateral process with single small posterior tooth and two small lateral spines with a wide, U-shaped emargination between them; smallest spine near base of tooth and bearing an apical seta, largest (anterior) sharply pointed, with a sub-apical seta. Tergites 2-5 of similar form, quadrate, transverse, with 4-5 discal setae on each side; lateral processes each with anterior and slightly smaller posterior teeth, stout but pointed at sclerotized, curved apices; lateral spines with sharp, sclerotized tips; larger of lateral spines near midpoint between teeth, bearing a sub-apical seta on posterior side, smaller spine arising from mid-length of posterior tooth, bearing a sub-apical seta on anterior side. Ventrites 2-6 smooth, convex, with 4-7 small fine setae on each side. Lateral process of tergite 6 with posterior tooth absent, both spines with sub-apical seta on posterior side. Tergite 7 narrower than preceding tergites, with four small fine setae on each side, with lateral process positioned and directed ventrally, not in same plane as preceding processes, anterior tooth reduced to a rounded lobe and posterior tooth absent, two posteriorly curved spines with sub-apical setae on posterior sides; sternite 7 roughly semicircular, transversely rugose apically, with three small discal setae on each side, the pair of larger setae along apical margin, with two smaller ones between them. Tergite 8 narrower than tergite 7, narrowing to broadly rounded apex, with lateral process reduced to a narrow ridge with two posteriorly curved spines only, posterior spine very reduced; spines with sub-apical setae on posterior sides; sternite 8 semicircular, with three small discal setae on each side, posterior most pair at sides of a transverse, raised area near apex. Tergite 9 short, bearing large divergent urogomphi, each gradually tapered and more sclerotized toward upturned, very sharp apices; cleft between urogomphi V-shaped with a narrowly rounded apex; base of uro gomphus laterally with a single small, tooth-like protuberance, not heavily sclerotized, with a fine seta on mesal side near base; other long fine setae present on side of base of urogomphus and ventrolateral side of urogomphus to about mid-length, the latter arising from small protuberances. Genital segment (female pupa) roughly trapezoidal, smooth, with two divergent, protruding papillae bearing a single small seta laterally, papillae with a shallow V-shaped emargination between them.

Glyptotus cribratus larval, pupal and reared adult material examined.

Specimens collected in USA. "FLORIDA: Highlands Co., Archbold Biol. Sta., S of Lake Placid, S. side of Lake Annie, 27°12'35"N, 81°21'W, 19 April 2003 / In soft rotten dry wood of low dead branch on live Quercus virginiana; W. E. Steiner, J. M. Swearingen et al. collectors" (3 L); Same data except "Reared from larva; emerged October 2003, larval exuvia not recovered" (1 A); "FLORIDA: Highlands Co., Archbold Biol. Sta., S. of Lake Placid, forest tract, NE part, 27°12'N, 81°20'W, 19 April 2003 / W. E. Steiner & J. M. Swearingen collectors / In pithy rotten wood of dead standing oak branch, mixed scrub forest burned ca 1 year ago" (2 L); "FLORIDA: Highlands Co., Archbold Biol. Sta., S. of Lake Placid, hill area E of Station, 27°11'N, 81°20'30"W / 31 December 2006, W. E. Steiner, J. M. Swearingen, A. W. & B. B. Norden, collectors / In dry rotten wood of recently fallen dead branch of live oak" (1 L); "FLORIDA: Highlands Co., 2 km N. Cornwell at Kissimmee River, 1 March 1984 / In rotting wood of log of live oak / W. E. Steiner, A. G. Gerberich, J. E. Lowry collectors" (1 L); "GEORGIA: Camden County, Little Cumberland Island, 30°58'N, 81°25'W, 30 November 1997 / In dry soft rotten wood of hanging branch Quercus virginiana in maritime forest / W. E. Steiner, J. M. Swearingen, W. A. Dix, C. Wells collectors" (1 L); same data except "25 November 1998 / In dry soft rotten wood of dead branch in canopy of Quercus virginiana in maritime forest" (2 L); same data except "In pithy rotten wood of dead branch recently fallen from live oak, Quercus virginiana " (1 L); same data except "28 November 1998 / Associated with adult Glyptotus cribratus in dry soft rotten wood of small low branch on live Quercus virginiana in maritime forest" (1 L); "NORTH CAROLINA: Dare County, Kill Devil Hills, 35°59'33"N, 75°39'11"W, 23 February 2007, coll. W. E. Steiner & J. M. Swearingen / In dry rotten wood of recently fallen dead branch of s. red oak ( Quercus falcata )" (1 L); same data except "Reared from larva in dry rotten wood of recently fallen dead branch of s. red oak ( Quercus falcata ); pupated 25 April, preserved 1 May 2007" (1 P with larval exuvia); "SOUTH CAROLINA: Dillon Co.; Fork; Little Pee Dee S.P., sand area, 34°19'10"N, 79°17'06"W, 16 April 2012 / In dry soft rotten wood of dead branch of live Quercus laevis in open pine-oak sand scrub; colls. J. C. Ciegler, W. E. Steiner, J. M. Swearingen" (1 L); "SOUTH CAROLINA: Georgetown County; Huntington Beach, near Murrells Inlet, 33°30'51"N, 79°03'09"W, 15 April 2012 / In dry soft rotten wood of dead lower branch Quercus virginiana in maritime forest; colls. J. C. Ciegler, W. E. Steiner, J. M. Swearingen" (1 L); "TEXAS: Comal County, Espinazo del Diablo, 9 km SW Wimberley, 29°55'30"N, 98°09'05"W, 17 November 2013 / In dry pithy wood of recently fallen branch of living Quercus virginiana fusiformis / Colls. W. E. Steiner, J. M. Swearingen, J. R. Ott, E. Silverfine" (1 L); "TEXAS: Hays County, Driftwood, at Dutchman Vineyards, 30°06'09"N, 98°0'51"W, 15 November 2013 / In dry pithy wood of dead low branches on large living Quercus virginiana fusiformis / Colls. W. E. Steiner, J. M. Swearingen, J. R. Ott, E. Silverfine" (4 L); "TEXAS: Hays County, Freeman Ranch, NW of San Marcos, 29°56'23"N, 98°0'44"W, 15 November 2013 / In dry pithy wood of dead low branch on large living Quercus virginiana fusiformis / Colls. W. E. Steiner, J. M. Swearingen, J. R. Ott, E. Silverfine" (1 L); same data except second label "In dry pithy wood of recently fallen branch of large living Quercus virginiana fusiformis " (1 L); "TEXAS: Hays County, Rutherford Ranch area NW of Kyle; oak grove near pond, 30°02'49"N, 97°57'56"W, 16 November 2013 / In dry pithy wood of recently fallen branch of large living Quercus virginiana fusiformis / Colls. W. E. Steiner, J. M. Swearingen, J. R. Ott, E. Silverfine" (1 L); same data except "(Preserved 11 Dec. 2013) / In dry pithy wood of dead low branch on large living Quercus virginiana fusiformis " (2L); "TEXAS: Hays County, Rutherford Ranch area NW of Kyle; near old ranch house ruins, 30°04'0"N, 97°56'37"W, 16 November 2013 / In dry pithy wood of recently fallen branch of large living Quercus virginiana fusiformis / Colls. W. E. Steiner, J. M. Swearingen, J. R. Ott, E. Silverfine" (1 L); "TEXAS: San Patricio Co., 12 km NE Sinton, Welder Wildlife Refuge, 8 December 1984, W. Steiner, B. Gill & D. Whitehead collrs. / In rotting wood of log of Celtis / larva coll. 8 Dec. 84, pupated 25 Apr. 85, eclosed 14 May 85, preserved 1 June" (1 adult pinned with larval and pupal exuvia); "VIRGINIA: City of Va. Beach, First Landing S. P., beach campground, 36°55.4'N, 76°2.8'W, 16 June 2007 / In pithy rotten wood of dead branch recently fallen from live oak, Quercus virginiana / W. E. Steiner, J. M. Swearingen et al. collectors" (1 L).

Specimens intercepted from MEXICO." Glyptotus sp. det. T.J. Spilman 1982, ex Mexico, at Hidalgo 4194, in Prosopis sp. stem, at Brownsville, #11491, 22v82, 82-6571" (1 L); " Glyptotus sp. det. T.J. Spilman 1983, ex Reynosa, Mexico, 8iii83, at Hidalgo 4194, on stem Prosopis juliflora " (1 L); " Glyptotus sp. det. T.J. Spilman 1984, ex Mexico, at Laredo, 17843, in rotting log, 4xii83, 84-549" (1 L).