Mischocyttarus, Saussure, 1853

Benda, Daniel, Pohl, Hans, Beutel, Rolf & Straka, Jakub, 2022, Two new species of Xenos (Strepsiptera: Xenidae), parasites of social wasps of the genus Mischocyttarus (Hymenoptera: Vespidae) in the New World, Acta Entomologica Musei Nationalis Pragae 62 (1), pp. 185-195 : 193

Mischocyttarus (cephalothorax of female)

1 Cephalothorax almost entirely pale, light reddishbrown. ....................................................................... 2

– Anterior third of cephalothorax pale, posterior two thirds dark; dark colouration of prosternum reaches border between head and cephalothorax ventrally ( Fig. 1C ); maxilla short, wider than long (mx, Fig. 2A ); hosts: Mischocyttarus navajo Bequaert , M. flavitarsis (Saussure) , and M. pallidipectus (Smith) . ................... ................... Xenos bicolor Benda & Straka sp. nov.

2 Cephalothorax very small (length 0.80–0.86 mm, width 0.86–0.96 mm), head capsule elongate, almost half as long as cephalothorax ( Fig. 5B ); host: Mischocyttarus costaricensis Richards. .................................. .................. Xenos pallens Benda & Straka sp. nov.

– Cephalothorax large (length 1.43 mm, width 1.8 mm), head capsule shorter, about one third as long as cephalothorax ( Fig. 5C ); host: Mischocyttarus flavicans (Fabricius) .................... Xenos americanus Brèthes, 1923 .

Figures

Fig. 1. Xenos bicolor Benda & Straka sp. nov., host, female, cephalothorax. A – Mischocyttarus flavitarsis (Saussure, 1854) stylopised by X. bicolor sp. nov., lateral view; B – detail of host abdomen of M. navajo Bequaert, 1933, with two adult females; C–D – holotype of X. bicolor sp. nov. from M. navajo, cephalothorax; C – ventral side; D – dorsal side.Abbreviations: cll – clypeal lobe, lehc – lateral extension of head capsule, mst – mesosternum, mtst – metasternum, pst – prosternum (prosternal extension), sbmm – segmental border between mesothorax and metathorax, sbpm – segmental border between prothorax and mesothorax, sp – spiracle.

Fig. 2. Xenos bicolor Benda & Straka sp. nov., female, detail of cephalothorax, male, cephalotheca. A – detail of ventral side of cephalothorax from Mischocyttarus navajo Bequaert, 1933; B – detail of dorsal side of cephalothorax from M. flavitarsis (Saussure, 1854); C – frontal view of cephalotheca from M. pallidipectus (Smith, 1857); D – lateral view of cephalotheca from M. pallidipectus. Abbreviations: a – vestigial antenna, cl – clypeus, cll – clypeal lobe, coe – compound eye, dlf – dorsal labral field of labral area, fi – frontal impression, fr – frontal region, gn – gena, hyp – hypopharynx, lba – labial area, md – mandible, mx – vestige of maxilla, mxb – maxillary base, mxp – vestige of maxillary palp, ob – occipital bulge, os – mouth opening, pom – postmentum, prm – prementum, pst – prosternum (prosternal extension), sbhp – segmental border between head and prothorax, smxg – submaxillary groove, ssf – sensillum of supraantennal sensillary field, vlf – ventral labral field of labral area.

Fig. 5. Schematic drawing of cephalothorax of all known Xenos species parasitizing wasps of the genus Mischocyttarus Saussure, 1853. A – X. bicolor Benda & Straka sp. nov.; B – X. pallens Benda & Straka sp. nov., C – X. americanus (Brèthes, 1923).