Xenoceraspis Arrow, 1920

genus Xenoceraspis Arrow, 1920 View in CoL

Xenoceraspis , 1920, p. 453 (primary description); Bezděk 2006, p. 191 (catalogue); Krajčík 2012, p. 263 (catalogue); Bezděk 2016, p. 212 (catalogue); Schoolmeesters 2024 (online catalogue).

Type species

Xenoceraspis dispar Arrow, 1920 (= Dichelomorpha kurseongana Moser, 1917 , senior subjective synonym), by original designation.

Diagnosis

Body elongate (length 8.2–11.2 mm), moderately convex, dorsally covered by semierect setae and several extremely long erect setae on protonum and lateral sides of elytra. Clypeus transverse, anterior margin distinctly upturned with rounded angles. Frontoclypeal and occipital carinae absent. Eye canthus broad, short. Eyes rather small, only slightly extended beyond canthus laterally. Antenna with 10 antennomeres, club trimerous, distinctly shorter than antennal shaft. Labrum transverse, lobes rounded. Maxillary palpus tetramerous, apical palpomere nearly as long as palpomeres 1–3 combined. Labial palpus trimerous, considerably short. Pronotum convex, widest at about middle; base broader than anterior margin. Basal margin with two angular emarginations and rounded lobe between them. Scutellum broad, with two projections fitting into notches of pronotum basally ( Figure 22 View Figures 20–26 ). Elytra convex, distincly dilated laterally just in front of the metacoxal plate, sutural angle obtuse-angulate. Striae absent, humeral umbone distinct. Macropterous. Metafemora distinctly enlarged, with row of stout short erect setae on posterior margin; metacoxal plate remarkably enlarged. Metatibiae modified, considerably enlarged apically, terminal spurs absent or present. Mesotarsomeres 1–4 modified, strongly contracted, saucer-shaped, with setaceous pads ventrally, mesotarsomere 5 elongated, stout. Tarsal claws long, stout, symmetrical, equal in length; protarsal claws cleft apically. Parameres symmetrical, covered with moderately long, sparse, erect setae ( Figures 14–16 View Figures 14–19 ).

Sexual dimorphism distinctly developed in all known species: females have antennal club slightly shorter, metafemora and metatibiae unmodified, mesotarsomeres 1–4 much less contracted, about as long as wide.

Morphologically, Xenoceraspis seems to be related to Diphycerus , both genera share the same shape of protarsomere 5 with remarkably thick setae basally ( Figure 20 View Figures 20–26 ), whereas these thick setae are absent in Dichelomorpha and Dicheloschema ( Figure 21 View Figures 20–26 ). Xenoceraspis differs from Diphycerus in having a larger body size and remarkably sexually dimorphic metatibiae.

Etymology

Genus-group name Xenoceraspis is derived from Greek words ‘xenos’ (foreign), ‘ceras’ (horn) and ‘aspis’ (shield).Because the word ‘aspis’ is a femininum in gender, all species-group names associated with Xenoceraspis should be modified accordingly (Article 34.2 of ICZN 1999).