Orasema brachycephala, Baker & Heraty, 2020

Baker, Austin J. & Heraty, John M., 2020, The New World ant parasitoid genus Orasema (Hymenoptera: Eucharitidae), Zootaxa 4888 (1), pp. 1-84 : 44-46

Orasema brachycephala n. sp.

urn:lsid:zoobank.org:act:DD2BC544-F50A-4A6F-BB27-F97C12D3319F

( Fig. 22 )

Diagnosis. Distinguished from other members of the sixaolae group by the relatively elongate antennal flagellomeres (F2L:F2W = 1.8), including a comparatively quadrate anellus ( Fig. 22D ). Distinguished from O. sixaolae and O. nebula by the petiole being shorter in length than the hind coxa (female). Distinguished from O. tinalandia by more coarsely, reticulately sculptured mesoscutal lateral lobes and axillae ( Fig. 22E ), and by the wider/deeper anterior tentorial pits ( Fig. 22B ).

Description. Female. Length 2.2 mm ( Fig. 22A ). Color. Head and mesosoma dark brown with bluish iridescence. Mandible pale brown, darkened near edge. Femora and tibiae pale brown. Head ( Fig. 22B ). Head in frontal view subovoid; HW:HH = 1.4; face weakly reticulate, nearly smooth; longitudinal groove between eye and torulus absent; eyes sparsely setose, IOD:EH = 1.4; MS:EH = 0.5; malar depression weakly impressed adjacent to mouth; supraclypeal area slightly broader than long, nearly smooth; clypeus shallowly imbricate; epistomal sulcus distinct and sharply defined. Labrum with 4 digits. Mandibular formula not observed; palpal formula 2:2. Occiput with dorsal margin evenly rounded; temples absent. Pedicel globose, broader than F1. FL:HH = 1.7; anellus large; F2L: F2W = 1.8, F2L:F3L = 1.0; following funiculars subequal in length, equal in width; clava subovate ( Fig. 22D ). Mesosoma ( Fig. 22C, E ). ML:MH = 1.7. Mesoscutal midlobe weakly reticulate, sparsely setose; lateral lobe weakly reticulate. Axilla weakly reticulate; scutoscutellar sulcus broad, irregularly foveate, broadly separated from transscutal articulation; mesoscutellar disc as long as broad, weakly reticulate to smooth; frenal line as smooth band; axillular sulcus indicated by a strong longitudinal carina. Propodeal disc areolate-reticulate, with irregular median carina, smooth laterally ( Fig. 22F ); callus with several long setae on dorsal margin. Propleuron weakly reticulate. Prepectus mostly smooth. Mesepisternum reticulate. HCL:HCW = 2.2; HFL:HFW = 4.2, evenly covered with short, dense setae. FWL:FWW = 2.1, FWL:ML = 2.3; entirely setose, wing disc densely setose; submarginal vein with several long setae; stigmal vein perpendicular to anterior wing margin; postmarginal vein several times longer than stigmal vein. Hind wing costal cell with only 1 or 2 irregular rows of setae. Metasoma. PTL:PTW = 1.7, PTL:HCL = 0.7, areolate-reticulate, lateral margin rounded, ventral sulcus present with margins broadly separated. Antecostal sulcus foveate; acrosternite posteriorly rounded; apical setae of hypopygium with several long hairs on each side of midline. Ovipositor not visible.

Male. Unknown.

Hosts. Unknown.

Plant associates. Unknown.

Distribution ( Fig. 21 ). Brazil: RJ. Collected in January (one specimen)

Material examined. Holotype. BRAZIL. Rio de Janeiro: Gunabara Floresta de Tijuca , 22 ° 55’48”S, 43 ° 14’24”W, i.1974, M. Alvarenga [♀, deposited in CNC: UCRCENT00247554].

Etymology. From Greek brachy meaning “short” and cephal meaning “head” in reference to the relatively short/wide face.

Figures

FIGURE 21. Distribution map of species in the Orasema sixaolae species group.

FIGURE 22. Orasema brachycephala. Holotype female (UCRCENT00247554): A, habitus, lateral; B, head, anterior; C, mesosoma, lateral; D, antenna; E, mesosoma, dorsal; F, propodeum, posterior.