Eleodes (Tricheleodes) pilosus Horn, 1870

Smith, Aaron D., Dornburg, Rebecca & Wheeler, Quentin D., 2014, Larvae of the genus Eleodes (Coleoptera, Tenebrionidae): matrix-based descriptions, cladistic analysis, and key to late instars, ZooKeys 415, pp. 217-268 : 248-250

Eleodes (Tricheleodes) pilosus Horn, 1870 Figs 3D , 6C , 10D , 14B

Material examined.

Larval Eleodes pilosus specimens were reared from adults with the following collecting information: "NEVADA: Washoe Co. / N39°16.427', W119°47.070' / November 14, 2011 / P.Skelley, sifting lakeside dunes". A total of 208 eggs and larvae were reared and examined for this study, of which 94 survived until the 2nd instar or later. The following description is based on a detailed examination of nine 8-11th instar specimens.

Description.

TL: 14.2-26.0 mm, PW: 1.7-3.3 mm, PL: 1.4-3.4 mm, HW: 1.6-2.6 mm.

Head. Prognathous, weakly flattened, narrower than prothorax; sides rounded, strongly constricted before occipital foramen; color nearly as in body segments. Epicranial stem short, one-fourth head capsule length; frontal arms U-shaped, partially obscured by sculpturing. Frons and dorsal portion of epicranial plates rugose; sparsely setose; densely punctate, punctures minute, lacking setae. Ventrolateral portions of epicranial plates densely setose; setae golden, erect, most longer than antennal segment 2, interspersed with shorter setae; two stemmata present on each plate, pigmented spots often faded. Clypeus trapezoidal; swollen, weakly transversely raised medially; moderately punctate, rugose in basal half. Labrum slightly swollen, basal fourth darkly pigmented; sides rounded, minutely tomentose; two transverse rows of six to eight erect setae present medially and subapically; anterior margin straight. Epipharynx ( Fig. 10D ) anterior setal row with six stout spiniform setae, anterolateral margins with micro-setation; seven anterior sensory papillae present, arranged in two irregular longitudinal rows; four subanterior sensory papillae present, arranged as a transverse row subtended by two spinose setae; seven posterior sensory papillae present, arranged in an irregular cluster. Tormae asymmetrical, left side torma smaller with or without a small spine near emergent edge. Hypopharyngeal sclerome pentagonal, tricuspidate. Gula distinct, trapezoidal, widest in basal half. Antenna three segmented, cylindrical; first segment longer than second.

Thorax. Light to dark tan, darker longitudinally striated bands present on anterior margin of prothoracic tergum and posterior 5th of all thoracic tergites. Sparsely setose along dorsal margins of terga near striated bands, lateral margins more densely setose. Prothoracic tergum subquadrate, 1.5 × length of meso- or metaterga; lateral margins with pigmented band along entire length. Mesothoracic spiracle simple, ovate, approximately 1.5 × size of abdominal spiracle; reduced metathoracic spiracle visible, less than one-fourth size of mesothoracic spiracle. Prothoracic leg slightly longer, much thicker than meso- and metathoracic legs; tarsungulus strongly sclerotized, sickle-shaped; trochanter with two stout spines ventromedially, tibia and tarsus each with a ventromedial row of four to seven spines, number of spines often differing between prolegs. Dorsal surface of protibia (at rest) with basal sclerotized band; dorsal surface of protarsus sclerotized.

Abdomen. Light to dark tan, darker longitudinally striated bands present on posterior 5th of segments I-VIII. Abdominal sternite I moderately clothed in long erect setae, sparser medially, extending to posterior pigmented band, abdominal tergite I and segments II-VIII sparsely clothed in short to mid length setae. Lateral margins of abdominal laterotergites I-VIII darkly pigmented, ventral margin with two pigmented bands. Abdominal segment IX (pygidium) triangular in dorsal view, moderately clothed in long erect setae; marginal row of 10-20 socketed spines present apical half, apex not forming distinct sclerotized projection. Pygopods short, subconical, each with 16-20 erect spines.

Diagnosis.

Eleodes pilosus larvae can be separated from the other currently known Eleodes species by the pentagonal hypopharyngeal sclerome, lack of a caudal tooth on the pygidium, presence of 8-14 marginal spines on the pygidium, subquadrate prothoracic tergum, and having abdominal sternite I moderately clothed in long erect setae to posterior pigmented band.

Figures

Figure 3. Dorsal habitus of four Eleodes species: A Eleodes (Litheleodes) extricatus B Eleodes (Melaneleodes) anthracinus C Eleodes (Melaneleodes) carbonarius D Eleodes (Tricheleodes) pilosus. Scale bar = 5 mm.

Figure 6. Lateral habitus of three Eleodes species: A Eleodes (Melaneleodes) anthracinus B Eleodes (Melaneleodes) carbonarius C Eleodes (Tricheleodes) pilosus. Scale bar = 5 mm.

Figure 10. Epipharynges of four Eleodes species: A Eleodes (Litheleodes) extricatus B Eleodes (Promus) goryi C Eleodes (Promus) subnitens D Eleodes (Tricheleodes) pilosus. Scale bars = 1 mm.

Figure 14. Pygidia of two Eleodes species: A Eleodes (Eleodes) hispilabris B Eleodes (Tricheleodes) pilosus. Scale bar = 1 mm.