Eleodes (Promus) subnitens LeConte, 1851

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 : 245-248

Eleodes (Promus) subnitens LeConte, 1851 Figs 7C , 10C

Material examined.

Larval Eleodes subnitens specimens were reared from adults with the following collecting information: "USA: Arizona: Gila Co. / Tonto Natural Bridge SP / N34.3214, W111.4569 / 11.IX.2010, ADSmith". A total of 7 eggs and larvae were reared and examined for this study, of which four survived until the 2nd instar or later. The following description is based on a detailed examination of two 8-11th instar specimens.

Description.

TL: 23.1-30.8 mm, HW: 2.0-3.0 mm, PL: 2.0-2.9 mm, PW: 2.2-3.1 mm.

Head. Prognathous or weakly declined; weakly dorsoventrally flattened; width nearly equal to prothorax; sides rounded; strongly constricted before occipital foramen; color ferruginous, more heavily pigmented than body segments; punctation minute, moderately dense, separated by 2-4 puncture diameters. Epicranial suture stem length approximately one-third head capsule length; frontal arms sinuate, not obscured by sculpturing. Frons faintly rugose. Epicranial plates faintly rugose dorsally; lateral portions moderately setose; ventral portion of each plate with row of six or more long setae along anterior margin near buccal cavity confluent with setae on lateral portions of plates and a patch of short setae medially, forming a triangular pattern with its base near the anterior margin. Two stemmata present on each epicranial plate, pigmented spots often faded. Clypeus trapezoidal, swollen, darker in apical half, minutely punctate, punctation moderately dense, separated by 2-4 puncture diameters. Labrum swollen, sides rounded, basal half more darkly pigmented, medial setal row with six to seven erect setae, subapical setal row with seven to eight erect setae, anterior margin straight to weakly emarginate. Epipharynx ( Fig. 10C ) anterior setal row with six stout spiniform setae, anterolateral margins with micro-setation; six anterior sensory papillae present, arranged in two irregular rows; four subanterior sensory papillae present, arranged as a transverse row subtended by two spinose setae; eight posterior sensory papillae present, arranged in an irregular cluster. Tormae asymetrical with left torma smaller. Ligula apex densely microsetose, two long subapical setae present ventrally. Hypopharyngeal sclerome pentagonal, tricuspidate. Gula distinct, trapezoidal, widest in basal half, length subequal or greater than maximum width. Antenna three segmented, cylindrical, first segment subequal to second.

Thorax. Thoracic tergites light tan, prothoracic sternite anterior to legs ferruginous, thoracic sternites posterior to prolegs light brown. Prothoracic tergum wider than long, 1.2 × or more length of meso- or metaterga; anterior transverse striated band present, darker than protergal disc; lateral margins with distinct granulated band, darker than protergal disc. Posterior transverse striated band present on all thoracic tergites, unicolorous brown. Meso- and metathoracic tergites wider than long, each with a heavily sclerotized transverse line present on anterior fifth. Thoracic tergites sparsely setose on dorsal surfaces, lateral margins more densely setose. Mesothoracic spiracle simple, ovate, approximately 1.5 × size of abdominal spiracles; reduced metathoracic spiracle visible, less than one-fourth size of mesothoracic spiracle. Legs. Prothoracic leg slightly longer, much thicker than meso- and metathoracic legs; prothoracic tarsungulus strongly sclerotized, sickle-shaped; prothoracic trochanter with two stout ventromedially spines; prothoracic femur with ventromedial row of two spines and three to five longer setae, dorsal surface with faintly indicated basal sclerotized band; prothoracic tibia with ventromedial row of five to six spines or spinose setae, dorsal surface slightly more sclerotized than ventral surface. Mesotibia with four to five ventromedial spines.

Abdomen. Abdominal tergites and sternites I-VIII light tan, with slightly darker transverse striated bands present along posterior margins8, forming near contiguous unicolorous band around segments. Abdominal sternite I moderately clothed in long erect setae to posterior pigmented band. Abdominal laterotergites with lateral margins distinctly pigmented. Abdominal segment IX (pygidium) triangular in dorsal view, gradually reflexed to apex, urogomphi absent, apex lacking a distinct tooth, moderately clothed in short and mid length erect setae, dorsally sclerotization uniform throughout, lacking maculations; marginal row of 18-20 socketed spines present, arranged as single row around posterior two-thirds to one half of segment. Abdominal sternites 1-8 lacking longitudinal tomentose bands along lateral margins. Pygopods short, subconical, each with 17-24 erect setae.

Diagnosis.

Eleodes subnitens larvae can be separated from the other currently known Eleodes species by the pentagonal hypopharyngeal sclerome, prothoracic tergum wider than long, 8th and 9th abdominal tergites not darker than proceeding segments, lack of a caudal tooth on the pygidium, and the presence of 5-6 ventromedial spines on the protibia.

Figures

Figure 7. Lateral habitus of the head and thoracic segments of three Eleodes species: A Eleodes (Melaneleodes) anthracinus B Eleodes (Litheleodes) extricatus C Eleodes (Promus) subnitens. 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.