Orthocentrus pentagonum Broad

Veijalainen, Anu, Broad, Gavin R. & Sääksjärvi, Ilari E., 2014, Twenty seven new species of Orthocentrus (Hymenoptera: Ichneumonidae; Orthocentrinae) with a key to the Neotropical species of the genus, Zootaxa 3768 (3), pp. 201-252 : 209-210

Orthocentrus pentagonum Broad , sp. nov.

Figs 1 B, 6 D, 8 D, 11 D, 13 D.

Fore wing length 2.4–2.8 mm.

Whole body, especially head, laterally flattened.

Face medially 1.0x wider than high; head entirely smooth and polished except for small coriaceous area on edge of antennal shelf, face with shallow punctures, eyes not setose, dorsal ridge of face inbetween antennal sockets without a median prominence; face profile very straight except just before antennal sockets impressed, edge of clypeus very straight, antennal sockets on a high shelf; malar space with narrow, very shallow, slightly curved sulcus, represented by discrete line, not microsculptured; maxillary palp short, reaching to fore coxa. In dorsal view, head posteriorly deeply concave, temples distinct, posterior ocelli distant from eye by 0.7x ocellar diameter, anterior ocellus separated from eye by 1.5x ocellar diameter, lacking ocellar-ocular grooves. Minimum distance between antennal sockets very narrow, sockets almost touching each other; antenna thick, curled, with 20– 21 (n=47) transverse and similar-sized flagellomeres which not gradually shortening apically; basal flagellomere 1.1x as wide as high and about 1/4 of the length of scape; scape parallel-sided.

Mesosoma smooth and polished except pronotum slightly coriaceous antero-dorsally, postero-ventral corner of pronotum with short striae or vague rugae, propodeum with coriaceous microsculpture, especially antero-medially; mesoscutum lacking notauli; in profile, scutellum not particularly high, metapleuron not convex; propodeum with complete posterior transverse carina, median longitudinal and lateral longitudinal carinae weakly present posterior to spiracle, median longitudinal carinae faint or lacking anteriorly, spiracles small.

Legs all slightly flattened, broad; coxae and femora polished, tibiae and tarsi coriaceous-granulate; hind coxa 1.1x as long as first tergite, hind femur 2.6x as long as high, hind tibia 3.0–3.8x as long as apically wide; tibiae dorsally with spine-like setae.

Wings somewhat narrow, cells thus comparatively long and narrow; fore wing with areolet closed but 3rs-m sometimes weak, areolet relatively large, longer than high, anterior side about same length as vein Rs+2r, 2rs-m shorter than 3rs-m, 2m-cu meeting areolet at apical 0.6–0.7, vein Rs straight; hind wing vein cu-a intercepted below middle.

First tergite long elongate, 2.0x as long as apically wide, in dorsal view, slightly wider at spiracles; coriaceous, polished apically, with weak median longitudinal carinae, with transverse impressions originating at about middle or slightly behind middle of tergite, sloping posteriorly, not meeting centrally. Second tergite 1.3–1.6x times as long as apically wide; coriaceous with weak to fairly strong striae, polished posteriorly, transverse impressions originating at about middle or slightly posterior to middle of tergite, sloping anteriorly and posteriorly, not meeting clearly centrally, weakly delimiting central rounded rhombic area; basal thyridia rounded-rectangular, contrastingly coloured. Remaining tergites smooth and polished, lacking thyridia; third tergite sometimes with coriaceous microsculpture antero-medially. Ovipositor straight, thin, without notch; ovipositor sheath bluntly pointed, with setae longer than sheath width and strongly curved, backwards pointing.

Body setose except eyes, pronotum, mesopleuron, metapleuron; setae on propodeum, basal tergites and posterior sides of coxae very few, scattered on apical tergites.

Dark brown to blackish brown except mouthparts creamy, sternites creamy to light yellow or brownish creamy, fore and mid legs largely yellow, hind trochanter and trochantellus dull orange, antenna with scape, pedicel and variable number of basal flagellomeres dull yellow/orange, scape infuscate over entire dorsal side. Clypeus apically and sometimes dorsal ridge of upper face between antennae narrowly orange.

Male. Unknown.

Biology. Hosts unknown. All individuals were collected from high-altitude Costa Rican Quercus forest.

Etymology. Named after the elongate, pentagonal areolet (a noun in apposition).

Comments. Very similar to O. concrispus but differs most prominently in the strongly sculptured second tergite (matt and longitudinally striate versus predominantly unsculptured and shiny in O. concrispus ) but also differs in the larger fore wing areolet, the smaller number of antennal flagellomeres, smaller ocelli, darker dorsal surface of the scape, and the more strongly sculptured propodeum and second tergite.

Material examined. Holotype female: ‘ Costa Rica, Sn José Pv. [San José Province], Cerro de la Muerte, Quercus forest, 2700 m, VII.88, Gauld & Mitchell’ ( BMNH).

Paratypes: 9 ♀ Costa Rica, San José Pv, 20 km S Empalme, Cerro de la Muerte, 2800 m, V.88, Gauld; 4 ♀ Costa Rica, San José Pv, Cerro de la Muerte, Quercus forest, 2700 m, V.88, Gauld & Mitchell; 24 ♀ as previous but collection date VI.88 (all BMNH); 9 ♀ as previous but collection date VII.88 (4 ZMUT, 5 USNM); 1 ♀ Costa Rica, 2800 m, San José Pv, 20 km S Empalme, IX.88, I.D. Gauld ( ZMUT).

Figures

FIGURE 1. Lateral views: Orthocentrus shieldsi species-group (in part). A: anguillae, B: pentagonum, C: concrispus, D: hispidus, E: quercus, F: shieldsi. Scale 0.5 mm.