Epitragosoma Brown and Triplehorn, new genus
Creators: name: Brown, Kirby W.
name: Triplehorn, Charles A.
Publisher: name: Zenodo
Year: 2001
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Tenebrionidae
Epitragosoma

description: Epitragosoma Brown and Triplehorn, new genus
Figs. 1–8
Description. Body (Fig. 1) elongate­elliptical, convex, clothed with short but conspicuous pubescence. Head: (Fig. 5) convex; epistoma with median lobe prolonged, moderately acute; lateral lobes obtusely rounded, not prominent. Ventral post­genal process prolonged, narrow, sharp and slightly everted. Eyes large, weakly convex and not protruding, coarsely faceted; supraorbital carina absent to extremely weak. Maxillary palpus with apical segment securiform. Antenna (Fig. 6) not reaching hind margin of pronotum when extended caudad, basal six segments cylindrical with third and fourth segments longest and subequal, width one­half length, segments 7–10 somewhat flattened, subequal in length but each slightly broader than preceding segment, each with a tomentose sensory area, eleventh segment two­thirds as broad as tenth, rounded apically with apical half occupied with a tomentose sensory area. Pronotum: convex, lateral margin rounded, lateral marginal bead scarcely defined and not reaching posterior angle; lateral margin arcuate in dorsal view, widest at middle or at hind angles; apical and basal angles acute; apical margin broadly and shallowly concave; basal margin strongly bisinuate. Elytra: fused along suture, convex, broadly oval; pseudopleural crest faintly carinate from apex to humeri, interval narrow at apex, gradually widening towards humeri. Metathoracic wings: (Fig. 8) reduced and non­functional, venation vestigial. Prosternal process: (Fig. 4) horizontally produced behind coxae. Mesosternum: distinctly but not deeply excavate. Metasternum: short, strongly bifurcate posteriorly. Legs: stout; profemur weakly expanded apically and not acute; protarsus and mesotarsus with dense pads of golden setae on plantar surfaces of basal four segments, with occasional coarse, stout setae; metatarsus (Fig. 7) with pads more poorly developed and stout setae more prominent. Abdominal tergum 7 of female (Fig. 2) highly modified, sharply bifurcate with a deep central sinus; of male (Fig. 3) weakly bifurcate with a shallow V shaped sinus. Abdominal tergum 8 of female trapezoidal, wider apically; of male normal lunate in shape.
Etymology. The name of this genus refers to its resemblance to Epitragopsis Casey.
Type species. Epitragosoma arenaria Brown and Triplehorn, new species.
Comparison. This new genus resembles Lobometopon Casey and keys to that genus in Arnett 1960 (it is included in Arnett and Thomas 2001). It differs in the supraorbital carina usually totally absent, third antennal segment subequal to fourth (third much longer than fourth in Lobometopon), weak to absent lateral marginal ridge on pronotum almost never reaching posterior angles, and brachypterous wings with fused elytra and short metasternum. Only two other genera of Epitragini are brachypterous, Conoecus Horn and Tydeolus Champion. Both have the pronotum widest anterior to the midpoint. Conoecus has a deflexed prosternal process, convex rather than excavate mesosternum, and rounded posterior pronotal angles. Tydeolus known from one species in Mexico has a flattened rather than convex head. Epitragosoma superficially resembles Epitragopsis Casey which has a weak prosternal process, weakly excavated mesosternum, and more protruding eyes.
The structure of the seventh tergite (Figs. 2, 3) is a remarkable and previously overlooked character in Epitragini. It is sexually dimorphic in many genera and more highly modified in females than in males. The following discussion pertains to females. The seventh tergite in Cyrtomius Casey, Bothrotes Casey and most Pechalius Casey has an apical cavity with a central projection. In Epitragosoma, Lobometopon, Pechalius dentiger (Horn) and Metopoloba Casey the apical cavity lacks a central projection. In Lobometopon, and Epitragosoma the cavity is deep and located between two pronounced projections that in Epitragosoma are sharp and narrow. The seventh tergite is only weakly emarginate in Schoenicus LeConte and is unmodified in Epitragodes Casey.
description: Published as part of Brown, Kirby W. & Triplehorn, Charles A., 2001, EPITRAGOSOMA ARENARIA, A New Genus and Species from Texas (Coleoptera: Tenebrionidae), pp. 515-521 in The Coleopterists Bulletin 55 (4) on pages 515-519, DOI: 10.1649/0010-065X(2001)055[0515:EAANGA]2.0.CO;2, http://zenodo.org/record/10102874