Heterischnus bicolorator (Aubert)

Figs 2, 3

Rhexidermis bicolorator Aubert, 1965: 16. Syntype series of 14 specimens [ Musée de Zoologie, Lausanne, Switzerland]. Images of syntype (GBIFCH00759357) examined.

Diagnosis.

Heterischnus bicolorator can be distinguished from other Nearctic Heterischnus species by a combination of the following: 1) flagellum, clypeus, and mesosoma without white markings; 2) coxae black to dark brown; 3) gena rugulose-punctate; and 4) T2-3 brownish-red.

Description.

Female (Fig. 2). Body length: 7.7-8.2 mm. Fore wing length: 5.0-5.4 mm.

Color. Head black, except brownish-red mandibular apex. Antenna brown. Mesosoma black. Legs brownish-red with coxae and trochanters varying from black to dark brown, except for brown tarsomere 5. MS1 varying from 0.5 anterior black to dark brown with 0.5 posterior brownish-red, to entirely black; T2 varying from entirely brownish-red, to brownish-red with 0.1 posterior brown; T3 brownish-red with posterior 0.1 brown to dark brown; T4-7 dark brown to black. Wing membrane clear; veins light brown.

Head. Clypeus smooth with dorsal 0.6 punctate with punctures separated by 0.5-1.0 × their diameter becoming less dense apically; apical margin medially concave to nearly straight with blunted sublateral apices. Supraclypeal area rugulose-punctate. Gena rugulose-punctate ventrally, dorsally smooth with coarse punctures 0.5-1.0 × their diameter. Malar space 1.5-1.8 × basal mandibular width. Supraclypeal area rugulose-punctate. Vertex smooth with coarse punctures separated by 0.5-1.0 × their diameter. Antenna with 34 flagellomeres.

Mesosoma. Mesonotum smooth with coarse punctures separated by 0.1-0.5 × their diameter. Scutellum smooth with dense, coarse punctures separated by 0.2-1.0 × their diameter. Mesopleuron varying from densely, coarsely punctate to rugulose-punctate. Speculum coarsely punctate dorsally. Ventral division of metapleuron densely, coarsely punctate to rugulose-punctate. Dorsal division of metapleuron finely punctate. Propodeum rugulose. Propodeal carination complete, except lateral longitudinal carina obsolete anteriorly. Tarsal claws simple.

Metasoma. Postpetiole varying from granulate to rugulose. T2 length 1.4-1.5 × posterior width. T2-7 granulate with dense, shallow, punctation becoming sparser and indistinct posteriorly. Gastrocoelus longitudinally rugulose. Thyridium distant from T2 anterior margin by 2.0-3.0 × thyridial length.

Male. Not examined (not known from Nearctic region).

Material examined.

Non-type material: Canada • 1♀; British Columbia, Stone Mountain Park; 5500 ft; 20.vii.1973; H. & M. Townes; EMUSENT00000302 • 1♀; same collection data as preceding; 22.viii.1973; H. & M. Townes; EMUS00000151 . USA • 1♀; Alaska, Umiat; 20.vii.1947; C. Schultz; USNM .

Distribution and biology.

Heterischnus bicolorator is known from western Europe and as far east as Chita Oblast in Russia (Yu et al. 2016). In the Nearctic, it is known only from two localities in Alaska and British Columbia (Fig. 3), but is likely present throughout the intervening areas, including the Yukon Territory. No host information is known.

Comments.

The three Nearctic specimens examined agree with both the original description (Aubert 1965) and images of a syntype specimen. No significant color or morphological differences could be found that would indicate that the examined Nearctic specimens are not conspecific with Palearctic specimens of H. bicolorator .