Otiocerus Kirby, 1821

Chen, Weiqiang, Dietrich, Christopher H. & Zhang, Yalin, 2025, On the genus Otiocerus with a new species and two new combinations to Shellenius (Hemiptera: Fulgoromorpha: Derbidae), Zootaxa 5633 (3), pp. 553-563 : 555

Otiocerus Kirby, 1821

Kirby, 1821: 13; Fitch, 1851: 46; Fitch, 1856: 394; Fowler, 1900: 74; McAtee, 1923: 45; Dozier, 1928: 129; Ball 1928: 196; Osborn, 1938: 326; Metcalf, 1945:167; Fennah, 1952: 155; Wilson & McPherson, 1980: 21; Bartlett et al., 2011: 25; Bartlett et al., 2014: 154; Bahder et al., 2023: 575.

Diagnosis. Body fragile. Head strongly extended forward and highly compressed laterally, in lateral view, with dorsal margin straight, and junction between vertex and frons obtusely angular. Antennae elongate and nodose below eyes, with elongate, tortuous appendages at base. Tegmina very elongate, clavus open. Wings with nearly straight anterior margin.

Description. Body oblong, small and fragile. Head large and elongate, in dorsal view, highly laterally compressed, width across eyes narrower than pronotum, lateral marginal carinae of vertex elevated and pustulate; in lateral view, strongly extended forward far beyond anterior margin of eyes, with dorsal margin straight and ventral margin curved, junction between vertex and frons obtusely angular. Postclypeus elevated centrally and compressed laterally. Rostrum inflexed, subclavate and triarticulate, with apical segment very short, reaching base of hind legs. Eyes reniform in lateral and posterior view. Ocelli small, obsolete and barely visible. Antennae located between eyes and postclypeus, subclavate, elongate and flexible, inarticulate and nodose, umbilicate at apex; with appendages emerging from base, single or double, almost as long as antenna flagellum, nodose, tortuous, and mucronate apically.

Thorax subglobose. Pronotum very short at middle, posterior margin deeply concave, both lateral parts deflexed, somewhat expanded. Mesonotum subrhomboid, scutellum not clearly separated from scutum. Tegmina cuneiform and very elongate, basal cells linear, apical cells quadrate; vein MP arising from base of Sc+R fork near base; ScP+RA separating from RP near middle; CuA forked, then fused again to form a closed cell 5 (C5); clavus open; Pcu connected with A 1 at basal third of clavus. Wings flabellate, shorter and wider than tegmina.

Abdomen subtriangular, with a median longitudinal carina on dorsum. Male genitalia with phallic complex spiny on upper side and thickened at base; gonostyli forceps-like and foliar, oblong and concave, with an apical arc sinuated internally and a small sinus. Female genitalia with gonapophysis VIII notched above a large sinus; gonoplac oblong; gonapophysis IX triangular with a straight base internally.

Remarks. This genus is the type genus of the tribe Otiocerini in Derbidae . It is similar to Apache Kirkaldy, 1901 and Shellenius Ball, 1928 , which also have strongly compressed and produced anterad head, antenna with single or double large appendage, tegmina with ScP+RA separating from RP near middle, MP arising from base of ScP+R fork, CuA forked near middle then fused again near distal third, common stem CuA 1+2 reaching posterior margin, and with a subapical line. Otiocerus differs from the other two genera mainly by the straight dorsal margin of the anterior head process with a distinct angle at the junction between the vertex and frons in profile, whereas in Shellenius the head is rounded apically and in Apache the head dorsal margin is sinuate in profile ( Kirby, 1821; Ball, 1928; Metcalf, 1938; Bartlett & O’Brien, 2014; Bahder et al., 2023).