Pholetesor chiricahuensis, Whitfield, 2006

Whitfield, James B., 2006, Revision of the Nearctic species of the genus Pholetesor Mason (Hymenoptera: Braconidae), Zootaxa 1144 (1), pp. 1-94 : 43-45

Pholetesor chiricahuensis , new species

( figs. 47 , 67 )

Holotype female. Body length 1.7 mm, forewing length 1.8 mm.

Head. Frons 1.4x broader at midheight than long down midline, finely and weakly punctate, producing dull metallic sheen between punctures; inner margins of eyes weakly converging towards clypeus. Antennae dark brown throughout, about same length as forewing; all but distal 5–6 flagellomeres with 2 ranks of placodes; flagellomere 2 3.5x longer than broad; flagellomere 14 1.2x longer than broad. Palpi moderate yellow­brown throughout. Head in dorsal view 2.1x broader than long down midline.

Mesosoma . Mesoscutum shallowly but distinctly punctate, becoming more indistinctly so posteriorly; surface with slight metallic sheen; width just anterior to tegulae just less than head width. Scutoscutellar scrobe straight to very weakly arched medially, composed of about a dozen sharp, regular, distinct pits. Scutellar disc mostly smoother, shinier than all but extreme posterior of mesoscutum, with widely scattered fine, shallow punctures; surface nearly flat, 1.2x longer than maximum breadth. Metanotum weakly retracted from scutellum, shallowly excavated mesad sublateral setiferous projections; transverse carinae on either side at about 1/3 of length poorly defined; sunken areas posterior to transverse carinae crossed by 3–4 short carinulae. Propodeum 2.0x broader than long at longest point, mostly very weakly rugulose, becoming shinier and smoother in posterolateral corners, with short irregular ridges radiating from nucha.

Legs. All coxae dark brown to black virtually throughout; trochanters lighter yellowbrown; fore­ and mid­femora very dark over basal half, gradually becoming lighter yellow­brown distally; hind femora evenly dark brown to black; all tibiae moderate yellow­brown proximally, becoming darker distally; especially so in hind tibiae; tarsi mostly deep brown. Spines on outer face of hind tibia of 2 thicknesses, approximately 20 in number (the thinner ones difficult to distinguish at times from normal hairs). Hind tibial spurs subequal in length, slightly less than half the length of the hind basitarsi.

Wings. Tegulae deep brown, translucent. Forewing venation deep brown, wings generally weakly tinted brownish. C+Sc+R, stigma, R1, 2r and 1Rs most strongly pigmented; R1 barely longer than stigma, about twice as long as distance from its tip to end of 3Rs fold along wing edge; 2r weakly arched, subequal with to slightly longer than 1Rs, the two meeting at a distinct 130­degree angle. Hindwing with weakly arched, strongly reclivous Cu+cu­a; vannal lobe weakly flattened, with very short fringe (at least near midlength of lobe).

Metasoma. Tergite I 2.4x longer than posteriorly broad, 1.5x broader anteriorly than posteriorly; lateral margins evenly curved, converging posteriorly; surface densely aciculorugose; longitudinal trend to sculpturing more obvious posteriorly; basal excavation shallowly, broadly u­shaped in cross­section, reaching to about 0.3 of length of tergite. Tergite II transverse­subtriangular, at least 2x broader posteriorly than anteriorly; lateral margins weakly arched; surface finely and longitudinally aciculate, the aciculations paralleling the lateral margins laterally; length about equal to posterior breadth of tergite I. Tergum III separated from II by crenulate furrow, unsculptured, slightly longer than II. Succeeding terga of usual unsculptured, unmodified, overlapping form. Laterotergites medium yellow­brown; in second tergum, laterotergite slightly darkened and sculptured near lateral margin of central tergite. Hypopygium about 1.3x longer than hind basitarsus, submedially weakly creased on either side; medial fold hairless, more flexible but not multiply creased. Ovipositor sheaths about same length as hypopygium, expanded distal hairy portions slightly shorter than hind basitarsi; sheaths narrow, fusiform, evenly hairy, very weakly decurved and more rounded dorsally than ventrally. Ovipositor weakly decurved over most of length, more strongly so near tip.

Males. The single associated male differs from the females in the following features: antennae longer, apically more slender (flagellomere 14 2.1x as long as broad); wing venation slightly greyer; 2r and 1Rs more distinctly angled; laterotergites very dark brown; tergite I not quite so slender or posteriorly narrowed. In the shape and sculpturing of the metasomal tergites, this male is extremely similar to the female from the same locality. Body length 1.6 mm; forewing length 1.8 mm.

Variation. Body length 1.6–2.0 mm, forewing length 1.8–2.2mm. The Arizona specimens are noticeably smaller than the others, with somewhat straighter lateral margins to the second metasomal tergite. In the Colorado specimen, the second tergite is more strongly trapezoidal, longer than in the other two and with a faintly bisinuate hind margin. Despite these differences, the scattered localities and lack of host records I associate these specimens with little hesitation due to strong similarities in winbg venation, leg coloration, propodeal sculpturing and ovipositor sheath shape.

Final instar larva. Unknown.

Cocoons. Not recorded, but likely to be hidden within the host cocoon when attacking Bucculatrix , and resembling those of P. bedelliae when attacking Elachista .

Material examined. Holotype female: ARIZONA. Cochise Co., SW Research Sta., 5 mi. W. Portal, 5400', Chiricahua Mts., 18­VIII­1978, malaise trap 8am–6pm (M. Wasbauer). Paratypes: 1 male, same data as holotype except 14–15­VIII­1978. CALIFORNIA: El Dorado Co., Fallen Leaf Lake, 2 females, 6­VIII­1985 (D. L. Wagner), Lot. No. 85H6, host: Elachista on Elymus . COLORADO. Clear Cr. Co., West Chicago Cr., 9800', 1 female, 11­VIII­1961 (S.M. Clark). FLORIDA: Monroe Co., Key Largo, John Pennecamp St. Park, 1 male, 14/ 16­XI­1986 (D. L. Wagner), Lot No. 86L33, host: Bucculatrix on Bourreria . NEW MEXICO. Tajique. 1 female, VI­25­1941 (R.H. Beamer).

Holotype from CDFA collection, deposited in USNM; paratypes in CDFA, CNC (Colorado specimen), Illinois Natural History Survey (California and Florida material).

Hosts. So far two divergent hosts have been recorded, Bucculatrix sp. (Bucculatrigidae) on Bourreria (a plant genus that in the U. S. appears to be restricted to Florida), and Elachista sp. (Elachistidae) on Elymus (Poaceae) . While the two hosts are quite unrelated, other species of the bedelliae ­group span these two host genera as well, so this is not particularly surprising or suspicious.

Comments. A single specimen from the Pinaleno Mts., Graham Co., Arizona in the CAS collection may possibly be a male of this species but differs in size (it is larger), metasomal tergite shape and sculpturing, and metanotum shape from the other (paratype) male, which is more positively associated with the females. The reared male from Florida, although geographically disjunct, is more similar to the other Arizona material. I suspect the disjunct distribution in North America only appears so because the areas further south in Mexico and the Caribbean are not well sampled.

This species has the most strongly narrowing first metasomal tergite in the bedelliae ­ group, and can be recognized on this feature easily, as well as by the short metacarp (R1) and subtriangular second tergite.

Figures

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).

FIGURES 60–71. 60–62, Ovipositor apparati, lateral view, of: 60, Pholetesor bucculatricis (Muesebeck); 61, P. zelleriae Whitfield; 62, P. masoni Whitfield. 63–65: Apex of female metasoma, lateral view, of: 63, P. dixianus Whitfield; 64, P. pinifoliellae Whitfield; 65, P. rhygoplitoides Whitfield. 66: Ovipositor apparatus, lateral view, of P. bedelliae (Viereck). 67, 68: Apex of female metasoma, lateral view, of: 67, P. chiricahuensis Whitfield; 68, P. longicoxis Whitfield. 69: Ovipositor apparatus, lateral view, of P. powelli Whitfield. 70, 71: Apex of female metasoma, lateral view, of: 70, P. thuiellae Whitfield; 71, P. rohweri (Muesebeck).