Pholetesor circumscriptus (Nees)

Whitfield, James B., 2006, Revision of the Nearctic species of the genus Pholetesor Mason (Hymenoptera: Braconidae), Zootaxa 1144 (1), pp. 1-94 : 77

Pholetesor circumscriptus (Nees)

( figs. 31 , 58 )

Microgaster circumscriptus Nees, 1834 . Hym. Ichn. aff. Mon. 1: 181.

Microgaster umbellatarum Haliday, 1834 . Ent. Mag. 2: 247­248.

Microgaster blancardellae Bouche, 1834 . Naturgeschichte der Insekten besonders in Hinsicht ihrer ersten Zustande als Larven und Puppen (Berlin). p. 156.

Microgaster lividipes Wesmael, 1837 . Nouv. Mem. Acad. Belg. 10: 63–64.

Microgaster flavolimbatus Ratzeburg , 184&. Ichn. deutsche Forstins. 2: 50.

Apanteles lautellus Marshall, 1885 . Trans. Ent. Soc. Lond., 1885: 219–220.

The above synonymy adapted from Wilkinson (1938).

This apparently circumpolar species has been fully treated in the Palearctic Region by Wilkinson (1938), Nixon (1973) and Papp (1983b). I will not attempt to completely redescribe it here but instead attempt to characterize the nearctic series I associate with this name relative to examined palearctic material and to P. pedias .

I have seen only 4 specimens, all non­reared females, from Alaska (Naknek) and in the Canadian National Collection, that I consider to be conspecific with the Palearctic P. cicumscriptus series I have seen. Of all European material examined (from England, Scotland, Netherlands, Sweden, Hungary, Northern Italy, Cyprus), the specimens from northern England and Scotland most closely resemble the Alaskan series in coloration and metasomal tergite shapes. Pholetesor circumscriptus appears to be an extremely variable species in the Old World, especially in leg and metasomal coloration.

The following notes on the Alaskan series are provided for comparative purposes: flagellomere 2 3.6x longer than broad; flagellomere 14 1.7x as long as broad. Stigma twice as long as broad,.9 as long as metacarp (R1), pellucid centrally, darker grey­brown peripherally (especially posteriorly). Propodeum smooth, polished, with series of oblique fine ridges extending forward on either side from nucha. Tergite I of metasoma evenly narrowing posteriorly, 3.2–3.5x as long as posteriorly broad, twice broader anteriorly than posteriorly, smooth, polished except with fine longitudinal posterior aciculations; tergite II strongly triangular, 2.6x broader posteriorly than anteriorly, 1.6x broader posteriorly than medially long, entirely polished, smooth except faint peripheral sculpturing. Ovipositor sheaths slightly longer than hind basitarsi, just over half as long as hind tibiae. Body length 1.8–2.0 mm, forewing length 2.0– 2.3 mm. Coloration dark for the species: all coxae dark; hind femora mostly infuscate; tergites I and II entirely dark brown to black; laterotergites moderate yellow­brown.

Short (1953) has examined the final instar larval head sclerites and reports that the labium has 7 pairs of setae, the maxillae each have 3 setae and the mandibles are each set with 12 long teeth (Short counted 13 but includes the upper tooth of the bifid tip).

None of the Nearctic material is reared, so associated cocoons are not available; cocoons I have seen associated with Palearctic specimens are white, translucent, apparently not banded, smooth, elongate­oval, capsule­like and suspended by a thread from each end within the host mine or shelter (appearance very similar to cocoons of P. salalicus from oak leafminers.

Figures

FIGURES 27–32. Forewings of: 27, Pholetesor caloptiliae Whitfield; 28, P. ornigis (Weed); 29, P. salalicus (Mason); 30, P. salicifoliellae (Mason); 31, P. circumscriptus (Nees); 32, P. pedias (Nixon).

FIGURES 39–59. Anterior metasomal tergites, dorsal view, of: 39, Pholetesor masneri (Mason); 40, P. bucculatricis (Muesebeck); 41, P. zelleriae Whitfield; 42, P. masoni Whitfield; 43, P. dixianus Whitfield; 44, P. pinifoliellae Whitfield; 45, Pholetesor rhygoplitoides Whitfield; 46, P. bedelliae (Viereck); 47, P. chiricahuensis Whitfield; 48, P. longicoxis Whitfield; 49, P. powelli Whitfield; 50, P. thuiellae Whitfield; 51, P. rohweri (Muesebeck); 52, P. variabilis Whitfield; 53, P. viminetorum (Wesmael); 54, P. caloptiliae Whitfield; 55, Pholetesor ornigis (Weed); 56, P. salalicus (Mason); 57, P. salicifoliellae (Mason); 58, Pholetesor circumscriptus (Nees); 59, P. pedias (Nixon).