Thyreodon niger, CRESSON, 1874

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 : 319

4. THYREODON NIGER CRESSON

Thyreodon niger Cresson, 1874: 375 . Lectotype ♀, MEXICO: Cordoba , designated by Cresson, 1916: 44 (PANS) [examined].

Fore wing length 22.2 mm; clypeus moderately convex, with apex pointed medially, with extreme apical margin out-flared; malar space about 0.5 times basal mandibular width; maxillary palp long with second palpomere both strongly broadened and flattened; lower face centrally rugose; frons with a pair of very 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 1.4 times its own maximum diameter; head in dorsal view with gena rugoso-punctate, rather evenly rounded behind eye, occipital carina strong, its lower end sharp, not reaching hypostomal carina; antenna setaceous, with about 62 flagellomeres, the 20th slightly elongate, 1.1 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 unspecialized; mesoscutum sparsely but coarsely punctate, with broad, reticulated notauli that are confluent posteriorly, inner anterior margin of notaulus forming a sharp longitudinal crest; scuto-scutellar groove very deep, laterally margined by very strongly raised carinae; scutellum coarsely punctate, convex; mesopleuron moderately closely punctate, without a sternaular impression; metapleuron finely and closely punctate, with a few diagonal striae; propodeum laterally flattened, finely rugose/striate, abruptly rounded above and behind the spiracle, with a weak ridge; propodeum posterodorsally finely rugosereticulate, with a few sublongitudinal rugae posterolaterally, centrally with a single broad shallow longitudinal impression. Fore leg rather stout, with coxa with a bluntly rounded protuberance behind trochanteral insertion, with 5th tarsomere 0.9 times as long as preceding two tarsomeres, with tarsal claw long and with fine close pectinae; hind coxa in profile moderately small, its hind end more or less level with hind end of propodeum; hind femur slender, about 6.5 times as long as maximally deep; hind tarsus of male with moderately long, dense pubescence ventrally. Fore wing with abscissa of Cu 1a between Cu 1b and 2 m-cu 0.9 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+ missing. Male with subgenital plate small and convex, covered with fine hairs; claspers quite long, the dorsal apex obliquely truncate, the lower margin angled before apex, and with a shallow, broad dorsal notch; aedeagus in profile with apex up-turned, weakly inflated, rounded.

A shining black species without a noticeable metallic reflection; wings blackish infumate.

Remarks: Thyreodon niger is rather similar to T. deansi , from which it differs in having one rather than three longitudinal grooves on the propodeum, not having a convex, peripherally impressed propleuron, and not having a sternaulus.

Biological notes: Thyreodon niger is a widespread Mesoamerican species that ranges from northern Mexico south to Costa Rica. In Costa Rica only a single specimen has been collected, and it is one of the two species (out of 23) not yet found in the ACG. Its host is unknown.

Material examined: Lectotype ♀, MEXICO: Cordoba ( PANS).

Non-type material: COSTA RICA: Puntarenas Prov.: 1? sex, Amistad National Park, Estacion Las Mellizas, Fca Cafrosa, 1300 m, x.1989 (Ramirez & Mora ) ( INBio ). GUATEMALA: 1 ♀, Alta Verapaz, Cubilguitz (BMNH). MEXICO: Guerrero: 1 ♂, Venta del Zopilote, 900 m (Smith) (BMNH): Morelos: 1 ♂, Puente de Ixtla, 1200 m (Smith) (BMNH): Tamaulipas: 10 ♀, 4 ♂, nr Cuidad Victoria, ruta 101 W, vi.1975 (Porter & Weems) (FSCA).