Orthocentrus brevicornis, Humala, 2019

Humala, Andrei E., 2019, Mexican species of the genus Orthocentrus (Hymenoptera, Ichneumonidae: Orthocentrinae), Zootaxa 4709 (1), pp. 1-83 : 21-22

Orthocentrus brevicornis sp. nov.

( Figs 4 D , 10 D , 14 A , 17 A , 25 )

Material examined. Holotype ♀: México, Hidalgo, Huasca de Ocampo , rancho Sta.Elena, MT3, 25.XI–26.XII.2005, leg. A. Contreras et al. ( UNAM).

Description. Female. Fore wing length 4.0 mm.

Face medially 1.3 × as wide as high; smooth and polished, with shallow, sparse punctures, eyes not setose, dorsal ridge of face inbetween antennal sockets without a prominence; orbits divergent ventrally; face profile slightly rounded, edge of clypeus rounded, slightly impressed, antennal sockets not on a distinct high shelf (Hw/Fp = 9.4); subocular sulcus distinct, sharp, strongly bent towards occiput; maxillary palp reaching slightly beyond fore coxa. In dorsal view, head posteriorly moderately concave, temples distinct, protruding posterior to eye, about 1/3 of eye width, hind ocellus separated from eye by 0.9 × ocellar diameter, anterior ocellus separated from eye by 2.0 × ocellar diameter, ocellar-ocular grooves present. Minimum distance between antennal sockets slightly less than diameter of socket; antenna comparatively short, with 23 flagellomeres, which gradually slightly shortening towards apex of antenna; basal flagellomere about 2.0 × as long as apically wide and basal flagellomere about half of the length of scape; scape with internal surface slightly convex.

Mesosoma polished except for inconspicuous punctation on anterior of mesoscutum and pronotum with short weak striae postero-ventrally; sometimes with vague, coriaceous microsculpture on propodeum; mesoscutum anteriorly with distinct notauli; in profile, scutellum moderately high, metapleuron slightly convex; propodeum with posterior transverse carina complete, raised as distinct projections at level of lateral longitudinal carinae; median longitudinal carinae complete, lateral longitudinal carinae complete, spiracles medium-sized.

Legs moderately broad; coxae and femora polished, femora with inconspicuous alutaceous-coriaceous sculpture, tibiae and tarsi coriaceous-granulate; hind coxa 1.1 × as long as first tergite, hind femur 3.2 × as long as high, hind tibia 3.9 × as long as apically wide; tibiae with spine-like setae.

Wings not particularly narrow; fore wing without areolet, vein Rs slightly upcurved basally; hind wing with nervellus intercepted at lower third.

First tergite elongate, 1.4 × as long as apically wide, in dorsal view, slightly widened at spiracles; coriaceous, with indistinct median longitudinal carinae, with transverse impressions originating at about middle of tergite, sloping posteriorly, not meeting centrally. Second tergite 0.9 × as long as apically wide; coriaceous, with irregular longitudinal striae in basal third, with diagonal-transverse impressions originating at about middle of tergite, sloping posteriorly, not meeting centrally; basal thyridia nearly rectangular, contrastingly coloured, second thyridia not developed. Remainder of metasoma impunctate except third tergite smoothly coriaceous in basal third, with irregular striae, without thyridia. Ovipositor not visible; ovipositor sheath pointed, with sparse, long setae.

Body largely setose except eyes, pronotum, mesopleuron and metapleuron, setae scattered on metasoma and posterior coxae.

Dark to blackish brown except face medially—brown; clypeus, base of antenna ventrally yellow, inner orbits to ocelli level, malar space, mouthparts, tegula, subalar prominence, fore and mid coxae, trochanters, trochantelli and sternites yellowish creamy; propleuron, pronotum dorsoposteriorly, mesepimeron dorsally, apical margins of first second and third tergites and fore and mid legs largely yellow to light brown; hind legs rufous, with blurred marks on hind coxa dorsoapically, hind femur apically, and hind tarsus brown; subbasal ring of hind tibia—yellowish. Metasoma from third tergite brown.

Male. Unknown.

Biology. Hosts unknown.

Distribution. Mexico (Hidalgo).

Etymology. Named after the comparatively short antennae.

Comments. Compared with the other species that have a complete posterior transverse carina, short notauli, and open areolet, subocular sulcus strongly bent towards the occiput, unlike in O. coronadoae , O. rufipleuris , O. similis and O. varicolor . Similar to O.latus , O. luteoclypeus and O. maculae but differs in the hind coxa mostly rufous and other details of the colour pattern.

Figures

FIGURE 4. Lateral views: Orthocentrus montanus (in part) and O. maculae (in part) species-groups.A: montezuma, B: sierrae, C: tlaxcalensis, D: brevicornis, E: coronadoae, F: latus. Scale 1.0 mm.

FIGURE 10. Faces: Orthocentrus montanus (in part) and O. maculae species-groups. A: montezuma, B: sierrae, C: tlaxcalensis, D: brevicornis, E: coronadoae, F: latus, G: lopezi, H: rufipleuris, I: scutellatus, J: similis, K: tergalis, L: varicolor. Scale 0.2 mm.

FIGURE 14. Heads in dorsal view: Orthocentrus maculae and O. ungularis species-groups. A: brevicornis, B: coronadoae, C: latus, D: lopezi, E: rufipleuris, F: scutellatus, G: similis, H: tergalis, I: varicolor, J: elongatus, K: flavoorbitalis, L: hidalgoensis, M: longiventris, N: rhombifer, O: ungularis. Scale 0.2 mm.

FIGURE 17. Basal tergites: Orthocentrus maculae and O. ungularis species-groups. A: brevicornis, B: coronadoae, C: latus, D: lopezi, E: rufipleuris, F: scutellatus, G: similis, H: tergalis, I: varicolor, J: elongatus, K: flavoorbitalis, L: hidalgoensis, M: longiventris, N: rhombifer, O: ungularis. Scale 0.2 mm.

FIGURE 25. Distribution map of Orthocentrus in Mexico. O. brevicornis, O. maculae, O. tergalis, O. varicolor