Chasca Johnson & Musetti

Johnson, Norman F. & Musetti, Luciana, 2012, Genera of the parasitoid wasp family Monomachidae (Hymenoptera: Diaprioidea), Zootaxa 3188, pp. 31-41 : 34-36

Chasca Johnson & Musetti , new genus

urn:lsid:zoobank.org:act:0DD25D3C-48C2-40BC-A599-2DC850EE0AB7 urn:lsid:biosci.ohio-state.edu:osuc_concepts:276540 Figures 4–15

Type species: Chasca andina Johnson & Musetti , n.sp.

Description. Female. Length: 6.6–8.7 mm. Head in frontal view quadrate; head width across gena subequal to width across compound eyes; frons moderately convex; antennal insertions raised, forming modest raised ledge between eyes, divided medially by depressed area; inner margins of eyes weakly diverging ventrally; malar area posterior to malar sulcus mostly smooth, with few setigerous punctures, anterior to sulcus punctate; malar sulcus well-defined; apical margin of clypeus without teeth or lobes, longest medially; ocelli in small medial triangle, OOL> POL; vertex sculpture variable; occipital carina complete, reaching hypostomal carina ventrally; hypostoma narrow, weakly sclerotized; antenna flagelliform, 15-merous, inserted far above clypeus; flagellomeres covered with short bristles, longer fine hairs sparsely distributed; A2 short, length approximately 2 times width, A3–15 elongate, uniform in width; mandible relatively narrow, longer than wide, bidentate apically, teeth broadly acute; distignath weakly convex, not swollen basally; basal margin of distignath not expanded; basignath small, broadly fusiform.

Mesosoma: pronotal sculpture variable, produced anteriorly into distinct neck, transition between neck and collar marked by transverse carina; mesoscutum smooth, sparsely setose; notaulus present, arcuate, smooth; parapsidal furrow present; axilla smooth, sparsely setose, separated from disc of mesoscutellum by crenate furrow; mesoscutellar pit variable in shape, not crenulate anteriorly; central disk of scutellum quadrate, slightly longer than wide, posterior margin with single transverse row of subapical punctures; mesoscutellum largely smooth, with few scattered punctures; metascutellum (dorsellum) bulging, subquadrate; metapostnotum with pair of rounded posterior projections; mesopleuron punctate anteriorly, setose anteriorly and ventrally, with wide, smooth, nearly glabrous area adjacent to mesopleural sulcus; mesepisternal groove indicated by foveate line; scrobal groove indicated by transverse foveate line; mespisternum finely punctate, setose, protuberant ventrally; discrimen indicated by deep foveate longitudinal line of inflection, widened posteriorly to form small fusiform pit anterior to mid coxae, margin of pit strongly produced into fingerlike projections; metapleuron distinctly separated from propodeum by line of foveae, densely setose, coarsely sculptured; propodeum elongate, bulging dorsally, coarsely sculptured, setose throughout, with weak median longitudinal carina in anterior half; anterior margin of propodeum with pair of teeth opposite metapostnotal projections; fore and hind wings strongly reduced, brachypterous or micropterous; tibial spur formula 1-2-2; hind tibia without distinct scar at position of subgenual organ, distinctly, though weakly expanded in distal two-thirds; all tarsi 5-segmented, basitarsus longest tarsomere on all legs; pretarsal claws simple.

Metasoma: petiole moderately long (in comparison with many species of Monomachus ), robust, weakly to moderately bowed; segment 2 subequal in length to segment 3, only slightly widened apically; segments 2–5 as wide as high, not strongly compressed laterally; terga, sterna strongly sclerotized, loosely connected, lateral margins of terga surrounding sterna; ovipositor apparently minute, not visible externally; cercus platelike.

Male. Very similar to typical Monomachus ; length of body 5.0– 7.5 mm; fore wing length 3.9–5.8 mm; antenna 14-merous; fore wing with radial cell open apically ( Fig. 9 ); base of m-cu srongly displaced basad of bifurcation of Cu1b; cercus digitiform.

Etymology. The generic name refers to Chasca , the Incan goddess of dawn and dusk. The grammatical gender of the name should be considered as feminine.

Diagnosis. Females of Chasca are immediately distinguishable from all Monomachus by their shortened wings. Males are separable from most Monomachus by the open radial cell in the fore wing. This character is shared with M. paulus , a species from Argentina. Chasca may be distinguished from this species by the rounded to sinuate ventral margin of the clypeus that lacks the small submedial teeth of M. paulus ; the subequal, rounded to acute pair of mandibular teeth; and the small fusiform basignath. These differences may be summarized as follows:

Figures

FIGURES 4 – 9. Chasca andina Musetti & Johnson. 4, lateral habitus, holotype female (OSUC 186320; 5, head and mesosoma, dorsal view, holotype female; 6, head and mesosoma, lateral view, holotype female; 7, lateral habitus, paratype male (OSUC 18633); 8, head and mesosoma, dorsal view, paratype male (OSUC 18633); 9, stigma and radial cell of fore wing, paratype male (OSUC 18633). Scale bars in mm. Morphbank: http: // www. morphbank. net /? id = 579899

FIGURE 10 – 15. Chasca gravis Musetti & Johnson. 10, lateral habitus, holotype female (OSUC 19234); 11, head and mesosoma, dorsal view, holotype female; 12, head and mesosoma, lateral view, holotype female; 13, lateral habitus, paratype male (OSUC 19493); 14, head and mesosoma, dorsal view, paratype male (OSUC 19574); 15, antennomeres 4 – 5, paratype male (OSUC 19485). t, tyloid. Scale bars in mm. Morphbank: http: // www. morphbank. net /? id = 579882