Arrowcryptus, Leschen & Wegrzynowicz, 2008

Leschen, Richard A. B. & Wegrzynowicz, Piotr, 2008, Arrowcryptus, a new genus of Xenoscelinae of Erotylidae from Africa, Zootaxa 1968, pp. 45-57 : 46

Arrowcryptus new genus

Type species: Thallis jucunda Arrow

Diagnosis. Antennomeres compact, median carina and pits of mentum absent, stridulatory files and vertexal line of head absent, pronotum without sublateral carinae, procoxal cavities partially closed by prosternal process and hypomeron, edge of hypomeron notched, metepisternal ctenidium absent, ovipositor dilated with gonostyle subapical and well sclerotised with setae located at its base, tarsi without well developed ventral pads with tarsal 4 reduced in size and tarsal shelf present and bifid, elytral punctation confused and scutellary striole absent, elytra strongly explanate, wedge cell of hind wing absent.

Description. With the diagnostic characters of Xenoscelinae (character numbers are referenced to those used in the data matrix in Leschen 2003; characters that are variable for Xenoscelinae are indicated by an asterisk (*) with autapomorphies in bold). Antennal club 3-segmented, antennomeres compact with dense microsetae contained in apical canals. Lacinia with 2 apical lacinial spines (6*, these are strongly pigmented but there are additional spines that are included among the apical brush); pits of mentum absent (10*), a wide bead surrounds the lateral and anterior margins; apical labial palpomere subuliform (13 and 14*); transverse gular line present as a deep groove (21*), and extending laterally along entire ventral margin of eye; transverse (vertexal) line absent from vertex of head (31*), weak occipital lines present on posteroventral margins; stridulatory files absent from vertex of head (32); pronotum evenly convex (35, coded as parallel-sided in data matrix) without sublateral carina; anterior angles of pronotum well developed (36); anterior margin of prosternum smooth (39*); pronotal pits absent (44*); pronotal glandular ducts typically present in bead (46 and 47*); prosternal glands present (50), two pair are present (1 along anterior margin, the other at disc); procoxal cavity internally closed (51*); external closure of procoxal cavity “slightly open” (52*) and partially closed prosternal process and hypomeron (53*); trochantinal notch present but poorly developed; prosternal process apically forked; edge of hypomeron notched (54*); mesoventrite with shallow impressions present and bearing setae (but widely separated from posterior carinae of procoxal rests), mesoventral glandular ducts present (61); mesepisternal fovea present or absent (63*); metaventral pores usually absent (69); metepisternal ctenidium absent (73*); abdominal ventrites 1 and 2 free (74); submetacoxal lines present (77); abdominal glandular ducts present and along the posterior margins of the ventrites (80, 82); ovipositor dilated (92), with gonostyle subapical and well sclerotised with setae located at its base (96); spermatheca lacking apical pit and accessory gland of spermatheca present (100*); length of tarsomere 1 equal to tarsomere 2 (104); tarsi without well developed ventral pads, tarsomere 4 reduced (107*) and exposed in ventral view (108); tarsal shelf of tarsomere 5 present and bifid (109, 110); empodium with one seta (111*); elytral punctation confused (113*); scutellary striole absent (114*); elytra strongly explanate (116*); epipleuron complete and visible in lateral view; radial cell complete with a large medial fleck and absence of all veins (including the wedge cell) in the medial field (120*; based on A. skellyi which has a fully developed hind wing).

Remarks. In the description of T. jucunda Arrow (1936: 253) noted that the species may represent a new genus, and we have formalized this action by including two in the new genus: Arrowcryptus jucundus (Arrow) , new combination, and a new species described below. We place Arrowcryptus in Xenoscelinae based on the dicondylic meso-metaventral articulation, basal pronotal pits absent, partial externally-closed procoxal cavities, tarsomeres not strongly lobed below, and submesocoxal lines absent. Absence of stridulatory files, presence of prosternal, mesoventral, and abdominal glandular ducts, presence of submetacoxal lines, will distinguish Arrowcryptus from all members of this subfamily ( Loberonotha , Macrophagus, Othniocryptus Sharp , Protoloberus Leschen , Xenocryptus Arrow , Xenoscelis Wollaston and Zavaljus Reitter ).

The generic description is based on genitalic dissections of all species and one completely dissected male specimen. In these, the guts were empty so diet could not be assessed. Because the heavily pigmented head of A. jucunda the cephalic glands could not be examined and the tentorium was accidentally destroyed

Distribution. Kenya, Niger, Ghana, and Mali.