Thyreodon woodleyi, 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 : 315-316

1. THYREODON WOODLEYI GAULD SP. NOV.

Fore wing length 20.4 mm; clypeus convex, with apex strongly pointed medially and conspicuously flared outwards; malar space 0.6 times basal mandibular width; maxillary palp long with second palpomere broadened and flattened; lower face centrally closely and coarsely punctate; frons with a pair of dorsally divergent 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 1.8 times its own maximum diameter; head in dorsal view closely punctate, with gena weakly rounded behind eye, occipital carina strong, its lower end sharp, not reaching hypostomal carina; antenna setaceous, with 61 flagellomeres, the 20th transverse, 0.8 times as long as broad, the subapical ones with setae which are shorter than the diameter of the flagellomere. Pronotum short with anterior margin slightly thickened, not reflexed, and with posterior margin centrally swollen, forming a sharp angular keel which is separated from the anterior margin by a deep U-shaped groove; epomia weak but discernible on upper part of pronotum; propleuron closely and coarsely punctate, slightly convex, with lower corner flattened but not peripherally impressed; mesoscutum finely and closely punctate, with broad, shallow, reticulated notauli that are confluent posteriorly, inner anterior margin of notaulus unspecialized; scuto-scutellar groove very deep, laterally margined by a very strongly raised, ridged carina; scutellum with close, coarse punctures, convex; mesopleuron closely and coarsely punctate, without a sternaular impression; metapleuron finely and closely punctate with a few ridges anteriorly; propodeum laterally weakly flattened, anteriorly punctate grading to finely reticulate, rounded and without a ridge above and behind the spiracle; propodeum posterodorsally finely reticulate, centrally with a shallow longitudinal impression. Fore leg of female rather stout, with coxa with a bluntly rounded protuberance behind trochanteral insertion, with 5th tarsomere about 0.9 times as long as preceding two tarsomeres, with tarsal claw long and with close pectinae; 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. Fore wing with abscissa of Cu 1a between Cu 1b and 2 m-cu 1.1 times as long as abscissa of Cu 1 between cu-a and 1 m-cu. Metasoma with tergite I moderately slender, anteriorly slightly compressed; tergite II, in lateral view, 2.0 times as long as posteriorly deep. Male unknown.

A reddish brown species with lateral parts of tergites II–IV obscurely infuscate; wings strongly yellowish, with distal apices broadly blackish infumate.

Remarks: Thyreodon woodleyi is named in honour of Norman E. Woodley, in recognition of decades of identification of thousands of species of Belvosia (Tachinidae) reared by the ACG caterpillar inventory. T. woodleyi is a very distinctive species that is easily recognized by its colour pattern alone because no other species of Thyreodon in Costa Rica is uniformly reddish brown, although it superficially resembles Rhynchophion woodi described above. Morphologically it is strikingly distinct from other species in having the anterior margin of the pronotum slightly thickened, but not at all reflexed ( Fig. 46 ). These two traits suggest that T. woodleyi is one of the most basal species in the genus. Interestingly, both it and T. papei (another rather basal species) have yellowish wings with black apices, as do most species of Dictyonotus (Old World) and Rhynchophion , suggesting that this colour pattern may be a ground plan trait of the Thyreodon genus-group.

Biological notes: Thyreodon woodleyi is only known from a single individual that was reared from the larva of Eumorpha satellitia ( Sphingidae : Macroglossinae ) collected in seasonally dry forest in northwestern Costa Rica. The caterpillar was found feeding on Cissus pseudosicyoides (Vitaceae) and became a prepupa on 31 May 1999, when it was consumed by the wasp larva. The wasp larva spun a cocoon from which an adult emerged on 7 July 1999 [99-SRNP- 7477]. Two other Thyreodon larvae emerged from the same species of caterpillar in the same dry forest in the same season, each spinning the same massive cocoon as the one that eclosed. It is particularly striking that more than 12 Malaise trap years of collecting from the immediate vicinity of this rearing did not capture a single individual of T. woodleyi . Furthermore, 441 wild-caught caterpillars of Eumorpha satellitia in this habitat, and 1026 wild-caught caterpillars of five species of Eumorpha in the ACG over 24 years produced only these three Thyreodon cocoons.

Material examined: Holotype ♀, COSTA RICA: Guanacaste Prov.: Area Administrativa, Sector Santa Rosa , ACG, vii.1999 (Janzen & Hallwachs) ( JHVC).

Figures

Figures 39–46. Thyreodon species. 39–40, head, postero-lateral; 39, T. erythrocera; 40, T. sharkeyi. 41–44, head, dorsal; 41, T. rivinae; 42, T. maculipennis; 43, T. atriventris; 44. T. woodleyi. 45–46, mesoscutum and pronotum, lateral; 45, T. walkerae; 46, T. woodleyi.