Pholetesor zelleriae, Whitfield, 2006

Whitfield, James B., 2006, Revision of the Nearctic species of the genus Pholetesor Mason (Hymenoptera: Braconidae), Zootaxa 1144 (1), pp. 1-94 : 21-23

Pholetesor zelleriae , new species

( figs. 18 , 41 , 61 , 79 )

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

Head. Frons 1.3x broader at midheight than long down middle, distinctly but shallowly punctate; inner margins of eyes evenly and moderately converging towards clypeus. Antennae very dark brown, approximately same length as forewing; all but distal 5 flagellomeres with 2 ranks of placodes; flagellomere 2 3x as long as broad; flagellomere 14 1.6x as long as broad. Palpi light amber throughout visible portions. Head in dorsal view twice as broader as long down midline.

Mesosoma . Mesoscutum densely and distinctly punctate, becoming more shallowly so posteriorly near scutellum; surface between punctures with dull, metallic sheen; mesoscutal width just anterior to tegulae slightly broader than head. Scutoscutellar scrobe deeply and distinctly crenulate, composed of about 15 punctures; mesoscutum immediately adjacent to scrobe smooth and distinctly depressed. Scutellar disc distinctly punctate, somewhat more sparsely so centrally, approximately 1.2x as long as maximum breadth. Metanotum weakly excavated anteriorly; sublateral setiferous lobes abutting posterior face of scutellum; mesoscutal postphragma weakly if at all exposed; transverse carinae at approximately midlength on either side well­ developed, setting off more posterior transverse depressions which are crossed by 3 or 4 short carinulae; posteromedial raised boss with 6–8 scattered setae. Propodeum 2.0x broader than long at longest point, coarsely rugulopunctate over entire surface, sometimes forming weak suggestion of medial longitudinal carina; sculpturing more strongly rugose posteriorly.

Legs. All coxae moderate to dark brown; legs otherwise light amber throughout except infuscate tips of the apical tarsomeres of forelegs, virtually entire tarsi of middle and hind legs and apices of hind tibiae. Spines on outer faces of hind tibiae about 35 in number, irregularly scattered, most easily distinguished from the thinner normal hairs in oblique lighting. Inner hind tibial spur just longer than outer, approximately half as long as hind basitarsus.

Wings. Tegulae dark brown, weakly translucent. Forewing venation evenly brownish; proximal portions of M­Cu and 1A–2A weakly pigmented. R1 1.1–1.2x as long as stigma, about 5x as long as distance from its distal end to end of 3Rs fold along wing edge. 2r weakly curved, slightly longer than 1Rs, meeting 1Rs at an indistinct obtuse angle. Stigma 2.6x longer than maximum breadth. Hindwing vannal lobe fringed with hairs of moderate length.

Metasoma. Tergite I 1.1x as broad posteriorly as long down midline, strongly arched along longitudinal axis, broadly excavated medially over anterior 0.3; lateral margins diverging posteriorly, especially over anterior 0.7; surface coarsely rugose, with narrow, weak, longitudinal posteromedial depression. Tergite II 2.2x as broad posteriorly as medially long, subquadrate but broadening slightly posteriorly, coarsely rugose; posterior margin weakly concave and marked by crenulate groove. Tergite III approximately of same width as II, subequal in medial length with II but with strongly rounded posterolateral corners; surface rugose throughout. Succeeding terga of normal unsculptured overlapping form, barely protruding from under anterior 3. Laterotergites yellowish brown, virtually hidden in dorsal view by broad tergites. Hypopygium 1.2–1.3x as long medially as hind basitarsus, evenly sclerotized and pigmented to sharp medial ventral fold, evenly hairy; apical angle not acuminate, forming distinct 60–70­degree angle in lateral view. Ovipositor sheaths more or less evenly tapering to a broader tip, apically bluntly rounded, approximately same length as hind basitarsi, hairy over most of expanded distal portions, more densely so near tip. Ovipositor weakly decurved.

Males. Body length 1.8–2.0 mm, forewing length 2.2–2.4mm (slightly smaller than female ranges). Antennae longer and more slender than in females, with more slender apical flagellomeres (flagellomere 14 2.6x as long as broad); all but distal 3 flagellomeres with 2 ranks of longitudinal placodes. Coloration of legs generally darker than in females (especially in hind tibiae). Tergite I of metasoma less strongly broadened posteriorly than in females, usually without signs of posteromedial longitudinal depression. Genitalia as in fig. 79 .

Variation. So far this species is known only from southeastern Canada and adjacent regions of the U.S., and therefore shows little obvious geographic variation. In addition, the season for adults seems extremely short (late June–early July), so little seasonal variability is evident. Females have a fairly large size range, considering that they mostly emerged from the same host species (body length 1.9–2.4 mm, forewing length 2.1–2.5 mm).

Final instar larva. Labium with 1 pair of setae on short tubercles. Maxillae each with one large seta. Mandibles set with 12–14 long teeth (not counting bifid tip).

Cocoons. White, nearly opaque, elongate­oval with blunt ends, relatively smooth but with irregular wisps of silk, especially near ends. Very similar to cocoons of a number of Dolichogenidea and Apanteles species , and to those of large P. bedelliae .

Material examined. Holotype female: ONTARIO. Basswood Lake , 13­VII­1963, ex Zelleria haimbachi, Forest Insect Survey no. S63­ 2037­01­8 . Paratypes: ONTARIO. Basswood Lake, 2 females, 6 males, 4–13­VII­1963, ex Zelleria haimbachi (FIS) . Chalmsford, 1 male, 4­VII­1963, ex Zelleria haimbachi (FIS) . Latchford , 1 female, 1 male, 11­VII­1963, ex Zelleria haimbachi (FIS) . Lunnel Lake , 1 female, 1 male, 12/ 24­ VII­1963, ex Zelleria haimbachi (FIS) . Nairn , 1 female, 21­VI­1955, ex Zelleria haimbachi (FIS) . North Bay , 2 females, 3 males, 29­VI–7­VII­1963, ex Zelleria haimbachi (FIS) . Sault Ste. Marie, 12 females, 22 males, 3–25­VII­1963, ex Zelleria haimbachi (FIS) . Skead , 1 male, 6­VII­1964, ex Zelleria haimbachi (FIS) . Thessalon , 1 female, 1 male, 9/ 20­VII­1963, ex Zelleria haimbachi (FIS) . Holotype and paratypes originally from and now deposited in CNC .

Other material: MANITOBA:. Sprague , 1 female, 30­VII­1942, ex Toumeyella sp. ( FIS) . MICHIGAN: Grand Traverse Co., 2 females, 26­ VI, 3­VII­1982, 2 females, 2males, 4–6­VII­1983, all ex Zelleria haimbachi on Pinus banksiana (N.C. Elliott) . ONTARIO. Biscotasing , 1 female, 10­VII­1941, ex Zale sp. ( FIS) . Little Curr. , 1 female, 6­VII­1954 (no collector given­CNC) . Midhurst , 1 female, 1 male, 30­ VI / 17­VII­1942, ex Zelleria haimbachi (FIS) . Nairn , 2 females, 1 male, 25–30­VI­1954 (no collector given­CNC) . Sault Ste. Marie , 1 specimen (sex undetermined), 12­VII­1962, ex Choristoneura pinus (FIS) . Skead , 1 female, 15­VII­1949, ex Neodiprion nanulus (FIS) . Sultan , 1 female, 14­ VII­1949, ex Zelleria haimbachi (FIS) . Timmins , 2 males, 10­VII­1948, ex Zelleria haimbachi (FIS) . Vermilion Bay , 1 female, 19­VII­1948, ex jack pine budworm ( FIS) . QUEBEC. Laniel , 4 females, 1 male, 24, 26­VII­1940, ex Zelleria haimbachi (C.E. Atwood­ CNC) .

Hosts. Zelleria haimbachi Busck (Yponomeutidae) is the only consistent host, despite extensive rearing of conifer­feeding microlepidoptera in eastern Canada. The other records are therefore suspect but certainly within reason, with the possible exception of Neodiprion nanulus , since all are from the same or similar microhabitats. Zelleria haimbachi feeds in needle sheaths of Pinus spp. , a habit shared by a number of micropleidopteran species.

Comments. Pholetesor zelleriae females can be distinguished from all other Pholetesor species with heavily sculptured third tergites by the shape and length of the ovipositor sheaths, shape and medial structure of the hypopygium and the sculpturing of the propodeum and anterior metasomal tergites. In the males, only the sculpturing differences, as well as slight differences in the tergite shapes and coloration of the legs and forewing venation, are useful. When more material is available for species of the pinifoliellae ­ group, male genitalic differences may prove useful.

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).

FIGURES 79–86. Male genitalia, ventral view, of: 79, Pholetesor zelleriae Whitfield; 80, P. masoni Whitfield; 81, P. bedelliae (Viereck); 82, P. variabilis Whitfield; 83, P. viminetorum (Wesmael); 84, P. ornigis (Weed); 85, Pholetesor salalicus (Mason); 86, P. salicifoliellae (Mason).