Pholetesor pinifoliellae, Whitfield, 2006

Whitfield, James B., 2006, Revision of the Nearctic species of the genus Pholetesor Mason (Hymenoptera: Braconidae), Zootaxa 1144 (1), pp. 1-94 : 35-36

Pholetesor pinifoliellae , new species

( figs. 21 , 44 , 64 )

Holotype female. Body length 2.4 mm; forewing length 2.5 mm.

Head. Frons 1.4x as broad at midheight as long medially, weakly punctate; inner margins of eyes converging towards clypeus. Antennae very dark brown throughout, slightly longer than forewing; all but distal 5 flagellomeres with 2 ranks of placodes; flagellomere 2 2.9x as long as broad; flagellomere 14 1.7x as long as broad. Palpi light yellow­golden throughout visible portions. Head in dorsal view 2.0x as broad as medially long.

Mesosoma . Mesoscutum evenly, finely and shallowly punctate, less distinctly so posteriorly, without noticeable metallic sheen; width just anterior to tegulae just barely greater than that of head. Scutoscutellar scrobe composed of approximately 15 fine crenulations, nearly straight medially. Scutellar disc slightly longer than anteriorly broad, distinctly but shallowly punctate. Metanotum weakly retracted from scutellum; sublateral setiferous lobes not prominent; transverse carinae at about midlength on either side setting off small, transverse depressions crossed by several short carinae. Propodeum mostly evenly and finely aciculorugose, with superimposed ridges posteriorly, radiating from nucha; width twice maximum length.

Legs. All coxae dark brown to black; forelegs otherwise dull yellow­brown except darkened apical tarsomeres. Mesothoracic legs mostly dark yellow­brown except lighterproximal 0.7 of tibiae. Hind legs mostly dark yellow­brown except lighter tinges along femora and proximal portions of tibiae. Spines on outer faces of hind tibiae 20–25 in number, irregularly scattered mostly posterolaterally. Apical spurs of hind tibiae whitish, subequal in length, the barely longer inner spur about 0.4 length of hind basitarsus.

Wings. Tegulae dark brown. Forewing venation evenly brownish except very dark grey­brown stigma, R1, 2r and 1Rs and slightly paler proximal venation. 2r weakly arched, somewhat longer than 1Rs, meeting it at distinct but nat aharp 155­degree angle. R1 1.2x as long as stigma, approximately 3.5x as long as distance from its distal end to end of 3Rs fold along wing edge. Stigma 2.5x as long as broad, distal edge nearly straight. Hindwing with vannal lobe evenly convex, with even, moderately long fringe.

Metasoma. Tergite I slightly broader posteriorly than medially long, broadening gradually, than rounding weakly posteriorly, evenly and finely and finely aciculorugose (strong longitudinal trend) with broad, smoother excavation medially over anterior 0.3; arched strongly in profile, with a narrow posteromedial depression evident. Tergite II subquadrate, 2.6x broader than maximum length, shortest medially, with weakly concave posterior margin; surface evenly aciculorugose throughout, weakly raised medially. tergite III as broad as II, approximately of same length as II but longest medially, aciculorugose over most of surface; posterolateral corners rounder and more weakly sculptured; separated from II by crenulate furrow. Laterotergites hidden from above, translucent deep brown. Posterior terga of normal, unsculptured, overlappiong form. Hypopygium 1.3x as long as hind basitarsus, strongly acuminate to a sharp tip, with weak submedial crease setting off a narrow, more translucent and hairless medial fold. Ovipositor sheaths slightly shorter than hypopygium, slender basally, then tapering broader to a bluntly beveled tip; hairy throughout expanded portions. Ovipositor weakly decurved.

Males. Antennae at least 10% longer than forewing, with more slender apical flagellomeres (flagellomere 14 2.5x as long as broad), with only the distal 3 flagellomeres having 2 ranks of placodes Coloration generally slightly darker than females on legs. Variation difficult to assess from two poor male specimens available.

Variation. Body length­ females 2.0– 2.4 mm, males both 2.1 mm. Forewing length females 2.0– 2.5 mm, males 2.2–2.3 mm. Because only a few specimens can be unequivocally associated with this species, variation is difficult to assess.

I have associated a smaller specimen from Laurel, Maryland with this species despite its slightly brighter leg coloration and coarser tergite sculpturing. These are trends to be expected in more southern individuals, judging from the trends in other species.

Far more doubtfully associated are 3 (also smaller) specimens from the Sierra Nevada in California, which appear somewhat intermediate in ovipositor sheath shape and length, wing venation and tergite sculpturing between P. pinifoliellae and P. variabilis . The third metasomal tergite is not so clearly rounded posterolaterally as in the typical pinifoliellae , and the first tergite lacks the longitudinal posteromedial depression (in both sexes; the depression is apparently less strongly expressed in the males in the type­series). These specimens may prove to be extreme individuals of P. variabilis , or an undescribed species.

Final instar larva. Unknown.

Cocoons. Unkown.

Material examined. Holotype female: ONTARIO. Ottawa , 28­VII­1950, reared ex microlepidoptera sp., no. 050­400 (Forest Insect Survey) . Paratypes: QUEBEC. Berthiersville , 1 female, 2 males, " ETE 1948 , host Paralechia pinifoliella , rearing no. 1001 (L Daviault) . Other material: MARYLAND. Laurel , 1 female, 21­VI­1965, malaise trap. Questionably associated: CALIFORNIA. Placer Co., Dollar Pt., 2 mi. NE Tahoe City, 2 females, 1 male, 24/ 29­VI­1979, Malaise trap (P. Adams) .

Holotype and paratypes in CNC collection; questionable California series in CDFA collection .

Hosts. The only determined host recorded is Exoteleia pinifoliella Chambers , a needle and shoot­borer on pines.

Comments. As with P. dixianus , interpretation of the limits of variation is difficult to impossible due to the small number of available specimens. Complicating the matter is the poor condition of the paratype series (which were chosen as paratypes only because they provide the only determined host record).

Nevertheless, separation of this species from P. dixianus , P. rhygoplitoides and P. zelleriae , the most similar species superficially, should not be difficult. The ovipositor sheaths of the 4 species are recognizably different in shape (see figures) and the combination of lack of propodeal areola, subequal hind tibial spurs, submedially creased hypopygium and broad angle between 2r and 1rs of the forewing is apparently unique among these 4 (each of the other species has all but one or two of these features in common).

Figures

FIGURES 17–21. Forewings of: 17, Pholetesor bucculatricis (Muesebeck); 18, P. zelleriae Whitfield; 19, P. masoni Whitfield; 20, P. dixianus Whitfield; 21, P. pinifoliellae Whitfield.

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).