Pholetesor glacialis (Ashmead)

Whitfield, James B., 2006, Revision of the Nearctic species of the genus Pholetesor Mason (Hymenoptera: Braconidae), Zootaxa 1144 (1), pp. 1-94 : 61-63

Pholetesor glacialis (Ashmead)

Protapanteles glacialis Ashmead, 1902 . Proc. Wash. Acad. Sci. 4: 248. Included in Pholetesor by Mason, 1981, Mem. Entomol. Soc. Can. 115.

The following notes on the holotype male are provided for the sake of comparison, although the identity of this species and its relationship with the rest of the group are uncertain (see below under Comments).

Holotype male. Head without unusual features for ornigis ­group; left antenna broken after flagellomere 1; right broken after flagellomere 9.

Mesosoma . Mesoscutal punctation very indistinct posteriorly near scutoscutellar scrobe; scrobe clearly but not strongly arched medially. Scutellum 1.3x longer than wide anteriorly, sculptured as on mesoscutum. Metanotum clearly retracted from scutellum, broadly excavated anteriorly mesad of sublateral setiferous projections. Propodeum apparently moderately rugose anteriorly (cracked medially by pinhole) with radiating ridges extending anteriorly from nucha; posterolaterally nearly smooth, depressed with some semitransverse ridging in extreme corners.

Legs. All coxae, trochanters and most of lengths of femora deep brown, becoming lighter distally near junction with tibiae (especially on forelegs); tibiae much lighter than femora on pro­ and mesothoracic legs, somewhat less so on metathoracic leg except near junction with femur; tarsi all concolorous with tibiae. Outer faces of hind tibiae with scattering of small spines typical of group. Inner hind tibial spur apparently much longer than outer but broken (also, right metathoracic leg missing).

Wings. Tegula moderately deep brown, translucent. Left forewing missing. Anterior venation of forewing (C+Sc+R, stigma, R1, 2r and 1Rs) distinctly more strongly brownpigmented than remainder of venation. R1 weakly curved, barely longer than stigma, extending about 0.75 distance to end of 3Rs fold (which curves slightly to anterior over distal half). 2r shorter than 1Rs, meeting at somewhat rounded but still definable junction (similar to that of P. salalicus ).

Metasoma. Tergite I 1.8x longer than maximum width, shallowly excavated anteriorly to about 0.4–0.5 of length; margins parallel over anterior 0.5, than converging in round curve to a narrower apex. Tergite II subtriangular, with barely curved, apically diverging lateral margins, rugose but with perceptible longitudinal trend in sculpturing medially; 1.5x broader posteriorly than medially long. Tergum III with very little sculpture and that immediately adjacent to groove separating it from II.

Label data. Muir Inlet, 6­12­99, Harriman Expedition '99, T. Kincaid, collector ; male type, no. 5705 USNM ; Protapanteles glacialis Ashm. male.

Comments. I have associated with the type a very similar male, from northwestern North America (Vedder, BC) and reportedly reared from Hyphantria textor (Harr.) (which is now synonymized under H. cunea (Drury) ( Arctiidae )). The record seems almost certainly in error; a cocoon is mounted with the specimen which is virtually identical to those of P. ornigis and P. salicifoliellae , and these cocoons are, in my experience, always found within a leaf mine or shelter, and made by a larva that has parasitized a leafminer.

The difficulty in placing this species, and in applying the name, stems from the uncertainty in associating isolated male specimens with females. Males tend to be more variable in tergite shape, coloration and size than females, and, in the ornigis­group, sexual dimorphism in coloration and tergite shape reaches the extreme found in the genus. As a result, it is often impossible to tell whether a lone male belongs to P. ornigis or P. salicifoliellae (or occasionally also P. salalicus ). Series are usually needed, and occasionally even then placement is uncertain unless the host is known. Since the male type of P. glacialis is not easily assigned to one of the above three species on morphological grounds, it will likely require more collecting in the type locality or vicinity to associate the male with a female. P. ornigis has not been recorded from Alaska, to my knowledge, but may well occur there, since it appears widely across northern North America. P. salalicus and P. salicifoliellae are known from the region ( P. salicifoliellae appears to be especially abundant), but the holotype of P. glacialis does not appear to match exactly the known and associated males of either, although it falls within the range of possible variability of both (in coloration and shape of the second tergite it more strongly resembles P. salalicus ; in the shape of the first tergite and in leg coloration it fits P. salicifoliellae better). As mentioned earlier, the cocoon resembles those of both P. salicifoliellae and P. ornigis (but not P. salalicus ). If the mistaken host were due to a mixed lot of Lepidoptera on the same host plant, it might seem possible to determine the likely host from that information; unfortunately, no host plant is given for the associated male from British Columbia and H. cunea is known to be a polyphagous species.

I choose for now to treat Pholetesor glacialis as a dubious distinct species, until more is known. The name would stand as the senior synonym of either P. salalicus or P. salicifoliellae if it were to prove conspecific; I am not prepared to sink either name on the weak available evidence.