Pholetesor circumscriptus

Whitfield, James B., 2006, Revision of the Nearctic species of the genus Pholetesor Mason (Hymenoptera: Braconidae), Zootaxa 1144 (1), pp. 1-94 : 76

The circumscriptus ­group

To this group I assign two species previously known from the Palearctic region: P. circumscriptus (Nees) , known in the Nearctic Region only from Alaska, and P. pedias (Nixon) , introduced into Ontario for biological control of Phyllonorycter blancardella (Fabricius) on apple leaves. Several other Palearctic species, including P. arisba (Nixon) and P.elpis (Nixon) , also appear to belong to this group.

These species are grouped together based on their common possession of the following features (most of which are shared by the ornigis ­group): 1) metanotum broadly retracted from scutellum, exposing portions of mesothoracic postphragma; sublateral setiferous lobes often not reaching scutellum; 2) areola and transverse carinae of propodeum absent, replaced by two series of ridges diverging obliquely from nucha; 3) metasomal tergite I much longer than broad, narrowing posteriorly, polished and sculptureless or very weakly sculptured posteriorly; 4) tergite II subtriangular, unsculptured, shorter than III down midline; 5) tergum III unsculptured, not rounded posterolaterally; 6) tergum IV unmodified, anteriorly overlapped by III and similar to succeeding terga; 7) sternites 3–6 of female anteromedially split or notched; 8) hypopygium evenly sclerotized to medial fold, not produced at tip; 9) ovipositor sheaths arising at or above midheight of valvifers; 10) volsellae of male genitalia each with 2 setae along medioventral edge (in Palearctic males from bisexual populations of P. circumscriptus —no males are known of either species in North America); 11) gonobase (basal ring of male genitalia approximately as long as broad, not transverse (see also comment under 10); 12) final instar larva with 6–7 pairs of labial setae; 13) final instar larva with 3 setae on each maxilla; 14) cocoon smooth, slender, capsule­ like, often banded by a region of thinner silk layer in middle, suspended within the mine of the host by a thread from each end; 15) hosts are various blotchmining genera of Gracillariidae , Tischeriidae and Elachistidae .

The smooth anterior metasomal tergites in the adults and 3 maxillary setae in the final instar larvae are the distinctive features of this group, separating it from the closely related ornigis ­group. The two groups together comprise an almost certainly monophyletic lineage within Pholetesor , and may eventually reach generic status.