Thyreodon deansi, 2004

Gauld, Ian D. & Janzen, Daniel H., 2004, The systematics and biology of the Costa Rican species of parasitic wasps in the Thyreodon genus-group (Hymenoptera: Ichneumonidae), Zoological Journal of the Linnean Society 141 (3), pp. 297-351 : 324-325

8. THYREODON DEANSI GAULD SP. NOV.

Fore wing length 16.5–17.8 mm; clypeus weakly convex, with apex bluntly pointed medially, with extreme apical margin rather abruptly out-turned; malar space about 0.6 times basal mandibular width; maxillary palp long with second palpomere both strongly broadened and flattened; lower face centrally sparsely but moderately coarsely punctate; frons with a pair of strong vertical crests between antennal sockets and with a sharp carina extending from outer rim of antennal sockets upwards, close to and parallel with eye margin; frons centrally rugose; ocelli small, the lateral ocellus separated from eye by about 1.6–1.7 times its own maximum diameter; head in dorsal view with gena coarsely punctate, rather evenly rounded behind eye, occipital carina strong, its lower end sharp, not reaching hypostomal carina; antenna setaceous, with about 61 flagellomeres, the 20th slightly transverse, 0.8–0.9 times as long as broad, the subapical ones with setae which are slightly shorter than the diameter of the flagellomere. Pronotum short with anterior margin strongly and broadly reflexed, and with posterior margin centrally swollen, forming an angular, centrally impressed ridge which is separated from the anterior margin by a deep U-shaped groove; epomia present on upper part of pronotum as a keel extending under anterior reflexed margin; propleuron sparsely punctate, with lower corner convex, expanded slightly to form a lobe which peripherally is shallowly impressed and bears a few weak rugae; mesoscutum sparsely but coarsely punctate, with broad, moderately shallow, reticulated notauli which are confluent posteriorly, inner anterior margin of notaulus forming a high, sharp transverse crest; scuto-scutellar groove very deep, laterally margined by very strongly raised carinae; scutellum punctate, convex; mesopleuron moderately closely punctate, with a sharp, deep, complete sternaular impression; metapleuron finely and closely punctate; propodeum laterally flattened, finely reticulate, abruptly rounded above and behind the spiracle, but without a distinct ridge; propodeum posterodorsally finely reticulate, with a few transverse rugae posterolaterally, centrally with a broad fairly deep longitudinal impression, laterally flattened with a weak to moderate lateromedian longitudinal impression. Fore leg of female rather stout, with coxa with a bluntly rounded protuberance behind trochanteral insertion, with 5th tarsomere 1.1–1.2 times as long as preceding two tarsomeres, with tarsal claw unusually long and with inner pectinae separated from outer pectinae by a short gap; hind coxa in profile moderately small, its hind end more or less level with hind end of propodeum; hind femur slender, about 6 times as long as maximally deep; hind tarsus of male with dense, moderately long pubescence ventrally. Fore wing with abscissa of Cu 1a between Cu 1b and 2 m-cu 0.9–1.0 times as long as abscissa of Cu 1 between cu-a and 1 m-cu. Metasoma with tergite I slender, anteriorly slightly laterally compressed; tergite II, in lateral view, 2.9–3.2 times as long as posteriorly deep. Male with subgenital plate small and convex, covered with dense coarse black hair; claspers long, the dorsal apex produced into a long spine-like projection, the lower margin not angulate before apex; aedeagus in profile with apex up-turned, weakly inflated, rounded.

A shining black species without a noticeable metallic reflection; wings of female uniformly blackish infumate. Male, similar in colour, but with antennae, facial orbits and fore leg yellowish marked, wings strongly yellowish infumate.

Remarks: Thyreodon deansi is named in honour of Andrew R. Deans, in recognition of his identification of thousands of slightly larger black microgastrine braconid wasps reared by the ACG caterpillar inventory. Although the male differs from the two females in colour, we are reasonably certain it is conspecific as both share a number of unusual features, including the slightly inflated, and peripherally impressed propleuron, and the sharply impressed sternaular groove. These two features distinguish T. deansi from the rather similar T. apricus , which also has three longitudinal grooves on the propodeum.

Biological notes: Thyreodon deansi is only known to occur in Costa Rica. It has only been collected three times, twice in the ACG and once on the Osa Peninsula. Although this species occurs well within the area of the ACG caterpillar rearing programme, it has not yet been encountered in many thousands of caterpillars and many tens of species of sphingids reared from these rain forest sites.

Material examined: Holotype ♀, COSTA RICA, Guanacaste Prov., Guanacaste National Park, Estacion Pitilla , 9 km S Santa Cecilia, 700 m, v.1990 (Biodiversity Survey) ( INBio ) . Paratypes: COSTA RICA: Guanacaste Prov.: 1 ♀, Guanacaste National Park, Estacion Cacao , 1000–1400 m, x.1989 (Blanco & Chavez) ( INBio ) : Puntarenas Prov.: 1 ♂ , Osa Peninsula, Corcovado National Park, Estacion Sirena , 1–100 m, ix.1993 (Fonseca) ( INBio ) .