Physotarsus varicornis Cameron 1886
Creators: name: Zhaurova, Kira
name: Wharton, Robert
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Ichneumonidae
Physotarsus
Physotarsus varicornis

description: Physotarsus varicornis (Cameron, 1886) (Figs 61, 62)
Scolobates varicornis Cameron, 1886: 310. Lectotype ♂, here designated, in BMNH. Scolobates variicornis: Dalla Torre, 1902: 328 (catalog, unjustified emendation). Physotarsus varicornis: Townes in Townes & Townes 1966: 139 (new combination); Yu & Horstmann, 1997: 455
(catalog).
Physotarsus davidi Gauld, 1997: 197 -198. Holotype Ψ in INBio, new synonym. Physotarsus davidi: Yu & Horstmann, 1997: 455 (catalog).
Diagnosis. Lateral ocelli separated by 0.8X their widest diameter from each other and about 1.8-2.0X their widest diameter from eye margin. Antenna with 35–38 flagellomeres. Pronotum and mesoscutum glabrous, impunctate. T1 about 1.9–2.1X as long as broad. Head entirely reddish brown. Mesosoma black with upper part of pronotum, anterior part of mesoscutum and upper margin of mesopleuron reddish brown. Metasomal tergites black. Hind legs black, trochantellus reddish, distal 0.5 of basitarsus and remaining tarsomeres bright yellow. Fore wing fuscous with subapical pale yellowish band.
This species is most similar to P. maculipennis, with which it shares the smooth body, pectinate claws, and dark wing with pale subapical band. Physotarsus varicornis is a distinctly darker species.
Description. Female: Body (Fig. 61) 7.4–10.0 mm, fore wing 7.0– 9.5 mm. Head (Fig. 62): Clypeal margin widely truncate laterally, with thick, somewhat angulate central lobe. Clypeus about 2.8X as wide as long, divided medially by transverse depression, with two small basolateral lobes weakly protruding in profile. Face densely covered with short setae. Anterior tentorial pits elongate and upcurved laterally. Malar space 0.5–0.6X width of mandibular base. Face 1.8X as broad as long, slightly protruding in profile, densely, finely punctate. Interantennal area flat, area immediately behind antennae weakly concave laterally, turning convex before reaching ocelli. Anterior margin of torulus situated at about 0.7 of eye height. Interantennal distance greater than distance between lateral ocelli. Widest diameter of torulus 1.4X widest diameter of median ocellus. Lateral ocelli separated by 0.8X their widest diameter from each other and about 1.8–2.0X their widest diameter from eye margin. Area between lateral ocelli flat, area behind ocelli not sharply declivitous. Antenna with 35–38 flagellomeres; first flagellomere about 4.0X longer than wide, 1.2X widest transverse diameter of eye, second flagellomere 0.6X length of first. Occipital carina present on ventral 0.2– 0.3 of head. Mesosoma: Anterior margin of pronotum medially slightly bifurcate, laterally rounded, slightly upcurved. Lateral groove of pronotum vestigial, present on dorsal 0.2. Pronotum and mesoscutum glabrous, impunctate. Epicnemial carina parallels anterior margin of mesopleuron. Mesopleuron impunctate, sparsely pubescent ventrally. Propodeum with pleural carina almost entirely complete, interrupted medially; impunctate medially, quite densely pubescent laterally. Tarsal claws almost fully pectinate. Fore wing stigma narrow; Rs+2r arising from basal 0.3–0.4 of stigma; marginal cell 2.5–3.1X longer than wide; 2rs-m 2.2–2.3X longer than abscissa of M between 2rs-m and 2m-cu; Cu1a about 0.7–0.9X length of 2cu-a; cu-a antefurcal relative to Rs&M. Metasoma: T1 about 1.9–2.1X as long as broad; surface convex in profile; spiracles somewhat protruding in profile. Cerci not protruding.
Male: Similar to female in structure and color.
Color. Head entirely reddish brown. Antenna with scape and pedicel reddish brown, flagellum blackish brown, becoming black, but with ill defined subapical dirty whitish band. Mesosoma black with upper part of pronotum, anterior part of mesoscutum and upper margin of mesopleuron reddish brown. Metasoma black with sternites paler yellowish brown. Anterior two pairs of legs reddish brown with coxae blackish; hind legs black, trochantellus reddish, at least distal 0.5 of basitarsus and all remaining tarsomeres bright yellow. Fore wing fuscous with one subapical pale yellowish band; stigma black.
Material Examined. Scolobates varicornis Cameron, 1886: Lectotype ɗ GUATEMALA, San Gerónimo (Champion) (BMNH). Physotarsus davidi: Paratypes, 2 Ψ COSTA RICA, Guanacaste Prov., Santa Rosa National Park, 300 m, vi.1985 & vii.1986 (Gauld & Janzen) (BMNH).
Remarks. Physotarsus varicornis has only been collected in Guatemala and Costa Rica. Only three specimens were collected in Costa Rica despite intensive sampling there (Gauld 1997): the two specimens noted above and the holotype of P. davidi collected from Guanacaste National Park, Los Almendros, 100m, viii-ix.1992 (Lopez) (INBio). The specimen of P. v a r i c o r n i s labelled as “BM type Hym 3b.1109” is here designated as a lectotype because Cameron (1886) did not specify whether he based his description on one or more male individuals. However, he did indicate a range in body size (10-11 mm), which opens up the possibility that he had more than one specimen.
Comparisons of the lectotype of varicornis with the paratypes of davidi showed that the three specimens are nearly identical, sharing the same distinctive color pattern and all the diagnostic features noted by Gauld for davidi. Gauld (1997) did not compare his Costa Rican species with previously described species of Physotarsus, thus overlooking the potential for synonymy. Physotarsus varicornis is most similar to P. maculipennis from Mexico. They are both large-bodied species with reduced body sculpture and very dark wings with distinctive pale bands or spots. Gauld (1997) suggested that the very striking color pattern of P. varicornis (as P. davidi) may mimic common ischnine cryptines such as some species of Joppidium Cresson.
description: Published as part of Zhaurova, Kira & Wharton, Robert, 2009, A revision of Physotarsus Townes (Hymenoptera: Ichneumonidae: Ctenopelmatinae), with description of 18 new species, pp. 1-52 in Zootaxa 2207 on pages 49-50, DOI: 10.5281/zenodo.189753