Pholetesor masneri (Mason)

Whitfield, James B., 2006, Revision of the Nearctic species of the genus Pholetesor Mason (Hymenoptera: Braconidae), Zootaxa 1144 (1), pp. 1-94 : 24-26

Pholetesor masneri (Mason)

( fig. 39 )

Teremys masneri Mason, 1981 . Mem. Entomol. Soc. Can. 115: 44. Holotype female, CNC no. 15789, examined.

Females. Body length 2.1–2.4 mm; forewing length 2.2–2.4 mm.

Head. Frons 1.2–1.3x broader at midheight than long medially, raised medially, shallowly punctate, without strong satiny sheen; inner margins of eyes strongly converging towards clypeus. Antennae yellow­brown at midlength, becoming very light golden on scapes and darker brown distally; antennal length 1.1x forewing length; all but apical 5–6 flagellomeres with 2 ranks of placodes; flagellomere 2 3.5–3.8x as long as broad; flagellomere 14 1.8–2.1x as long as broad. Palpi pale yellow­brown throughout. Head in dorsal view 1.6–1.8x as broad as long down midline.

Mesosoma . Mesoscutum with dense, fine, distinct punctation (interpuncture distances much less than 1 puncture width); interstices shiny but with faint metallic reflections; width just anterior to tegulae almost identical to that of head. Scuto­scutellar scrobe nearly straight medially, moderately broad, composed of 10–12 irregular, sometimes confluent pits. Scutellar disc more sparsely punctate than mesoscutum, especially cetrally; relatively smooth and shiny between punctures, about 1.3x as long as anteriorly broad (at broadest point); scutellar lunules of even semicircular proportions. Metanotum anteriorly nearly appressed to scutellum, sublateral setiferous lobes touching posterior margin of scutellum; transverse carinae on either side much closer to anterior margin than posterior, nearly parallel to posterior edge of scutellum, well developed medially but ending before reaching sublateral setiferous lobes. Propodeum twice broader than long, densely punctulorugose anteriorly, irregularly and obliquely sculptured posterolaterally, with strong, more or less oval medial areolar indentation which is less strongly sculptured within.

Legs. All legs light amber in color except infuscate tips of the fore and mid tarsi, most of the hind tarsi and (sometimes) the extreme apices of the hind tibiae. Spines on outer faces of hind tibiae 35–40 in number, mostly much thicker than normal hairs. Inner apical spurs of hind tibiae only slightly longer than outer and 0.4x as long as hind basitarsi.

Wings. Tegulae deep brown. Forewing venation mostly pale, nearly colorless except deep brown C+Sc+R, stigma, R1 and paler brown Rs, 2r and 1Rs. 2r and 1Rs subequal in length, meeting at a distinct but not sharp 130­degree angle. R1 1.1–1.2x as long as stigma, 4–5x as long as distance from its distal end to end of 3Rs fold along wing edge. Stigma 3x as long as maximum breadth. Vannal lobe of hindwing somewhat flattened subapically, with sparse but continuous fringe of short hairs.

Metasoma. Tergite I strongly arched and medially broadly excavated anteriorly, broadening posteriorly to very weakly rounded posterolateral corners, about as long as broad but arching strongly so measurement difficult; surface densely aciculorugose; slightly raised along medial line. Tergite II more or less quadrate, 2.8x broader than medially long, with a bisinuate, crenulate hind margin (weakly concave medially and curved forward again laterally); surface mostly longitudinally aciculorugose, more irregularly so laterally, slightly raised along medial line. Tergite III subequal in length with II, slightly broader, again with medially concave, crenulate hind margin but with posterolateral corners more rectangular; surface sculptured as on II. Tergite IV immovably fused to III but delineated from it by crenulate groove, shorter and narrower than III and with strongly rounded posterolateral corners; sculpturing as in II and III. Succeeding terga of normal overlapping, unculptured form and largely overlapped by I–IV. Laterotergites light yellow­brown, mostly to entirely hidden in dorsal view. Hypopygium 1.3–1.4x as long medially as hind basitarsi, more or less evenly sclerotized and pigmented to sharp medial fold, apically sharply angled at about 50 degrees in lateral view; preceding sterna apparently not split, at least through much of length. Ovipositor sheaths 0.5–0.6x as long as hind tibiae, shorter than medial length of hypopygium, gradually broadening over proximal half but nearly parallel­sided over apical half to a blunt tip; hairy over most of apical expanded portions. Ovipositor moderately decurved, especially near apex.

Males. Very similar to females except: antennae longer, more slender (flagellomere 14 3.0x as long as broad); all but apical 3 flagellomeres with 2 ranks of longitudinal placodes; probably not appreciably smaller than females but appearing so because metasoma shrinks more posteriorly in dried specimens; metasomal tergites less broad and transverse than in females. Color not significantly different than in females.

Variation. Very little is known of the geographical range of P. masneri , and nothing of the hosts it attacks. The available material is quite uniform in sculpturing, ovipositor sheath lengths, etc., and varies little in color.

Cocoons. Unknown.

Material examined. Redescription based on: Paratype female ( CNC)— ONTARIO. Spencerville, 15­VIII­1978 (L. Masner). Paratype male, same data. Other material: CONNECTICUT. Redding , 1 male, VIII­1939 (no collector given). ONTARIO. Hamilton, 1 female, 8–13­VIII­1981, Malaise trap (M. Sanborne). The holotype was examined but not used for the redescription measurements .

Hosts. Unknown.

Comments. The fusion of the fourth metasomal tergite to the third is unique among Pholetesor species , and unusual among Microgastrinae . The species is certainly distinct enough to warrant separate generic status on merely phenetic grounds, but shares so many features (not all clearly plesiomorphic) with P. bucculatricis and P. zelleriae that its separation as a distinct genus probably would leave Pholetesor as a paraphyletic group. Most likely it will also prove to be biologically similar to these two species. Valerio and Whitfield (2003) provide additional figures of both T. masneri and T. hanniae .

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).