Pholetesor powelli, Whitfield, 2006

Whitfield, James B., 2006, Revision of the Nearctic species of the genus Pholetesor Mason (Hymenoptera: Braconidae), Zootaxa 1144 (1), pp. 1-94 : 47-49

Pholetesor powelli , new species

( figs. 24 , 49 , 69 )

Holotype female. Body length 2.7 mm, forewing length 2.7 mm.

Head. Frons 1.5x as broad at midheight as long down midline, weakly punctate with dull satiny finish; inner margins of eyes weakly converging towards clypeus. Antennae dark brown to black throughout, slightly shorter than forewing; flagellomere 2 3.5x as long as broad; flagellomere 14 1.7x as long as broad; all but apical 5 flagellomeres with 2 ranks of placodes. Palpi light yellowish except dark brown basal segments. Head in dorsal view approximately 2x broader than long down midline.

Mesosoma . Mesoscutum shallowly, very finely punctate, becoming nearly impunctate at extreme posterior edge; surface dull, satiny; width just anterior to tegulae approximately equal to tha of head. Scutoscutellar scrobe weakly arched medially, formed of 15–20 irregular but sharp, fine pits. Scutellar disc slightly longer than anteriorly broad, smooth, with fine, widely scattered shallow punctures; lateral margins unusually straight. Metanotum more or less appressed to scutellum, very weakly excavated along anterior margin mesad sublateral setiferous lobes; transverese depression at midlength on either side crossed by 3–4 short carinae; anteromedial depression broad. Propodeum shallowly rugulose except weakly sculptured in anterolateral corners, with irregular ridgeing radiating from nucha and weak transverse medial ridging.

Legs. All coxae dark brown to black; fore and middle trochanters lighter yellowbrown, at least in part; fore femora darkened proximally, especially dorsally, with light yellow­brown apices; fore tibiae and tarsi light yellow­brown except darkened apical tarsomeres; mid and hind femora mostly dark brown to black, lightening at extreme apices; mid and hind tibiae moderate yellow­brown except darker apical 0.2 of hind tibiae; mid tarsi concolorous with tibiae, hind tarsi infuscate. Spines on outer faces of hind tibiae 25­30 in number, some more slender than others and more difficult to distinguish from normal hairs. Inner hind tibial spurs of hind tibiae slightly longer than outer, 0.4x as long as hind basitarsi.

Wings. Tegulae dark brown. Wings tinted brownish; forewing venation mostly medium brown; stigma, R1, 2r and 1Rs very dark brown, neraly opaque; R1 (metacarp) 1.2x as long as stigma, 4x as long as distance from it distal end to end of 3Rs fold along wing edge; stigma broad (length/width 2.0), edge facing 1Rs+M weakly convex; 2r slightly longer than 1Rs, weakly arched, meeting 1Rs at distinct 150­degree angle. Hindwing with Cu+cu­a weakly convex, moderately reclivous; vannal lobe barely flattened at midlength, fringed evenly with hairs of moderate length.

Metasoma. Tergite I barely broader anteriorly than posteriorly, with very weakly arched lateral margins, about 1.5x as long as posteriorly broad; surface longitudinally aciculate anteriorly surrounding shallow basal excavation, posteriorly aciculorugose with less conspicuous longitudinal element; apically with shallow depressions on either side of medial raised portion. Tergite II subequal in length with III, irregularly and longitudinally aciculate with small raised longitudinal medial ridge over anterior 0.5, posteriorly 2.5x as broad as medially long; posterior weakly crenulate margin nearly stright; lateral margins strongly arched. Third tergum unsculptured, longer than II. Succeeding terga not strongly telescoped under anterior ones in dried specimens. Laterotergites deep brown; posterior portions of metasoma entirely dark brown to black. Hypopygium nearly 1.5x as long as hind basitarsi; apically sharply acuminate, submedially weakly creased on either side, setting off narrow, more transparent and flexible medial fold. Ovipositor sheaths approximately same length as hypopygium, fully 3/4 as long as hind tibiae, broadly fusiformover most of length, ventrally more strongly curved than dorsally in profile; tip bluntly pointed; hairy over entire expanded portions; at broadest point nearly as broad as hind tibiae at midlength. Ovipositor evenly, weakly decurved.

Males. Similar in appearance to females except all but distal 3 flagellomeres with 2 ranks of placodes, flagellomere 14 longer. All femora black except distal portions of prothoracic, tibiae mostly to entirely dark brown­black. Tergite I 1.5–1.8x as long as maximum width; tergite II 2.0–2.2x as broad posteriorly as medially long, with slightly convex hind margin.

Variation. Body length 2.5–2.8 mm, forewing length 2.7–2.9 mm. All female specimens highly similar except that the specimen collected in August in Oregon from " Lithocolletis " on salal is considerably lighter in color, particularly in the mid and hind tibiae and wing venation.

Final instar larva. Labium with 1 pair of setae on short tubercles; maxillae each with one seta; mandibles set with 14–16 long teeth (not counting bifid tip).

Cocoon. Similar in appearance and location to that of Pholetesor bedelliae : white, satiny, blunt­oval, with coarse loose threads exteriorly, spun in the middle of host frass on the underside of skeletonized Gaultheria leaves or (I suspect) in the case of individuals reared from Phyllonorycter or Cameraria , spun within the host mine.

Material examined. Holotype female: CALIFORNIA. Santa Barbara Co., Santa Cruz Id., Canada Cervada, 4­II­1979, ex Lithocolletis on Quercus wislizenii, J.A. Powell no. 79B12, emgd. 1­III­79 (J.A. Powell). Paratypes: CALIFORNIA. Del Norte Co., Crescent City, 1 female, 26­V­1978 (H.& M. Townes). Marin Co., Tomales Bay State Park, 1 female, 3­III­1984, ex skeletonizer on Gaultheria shallon, JBW bo. 84C2, emgd. 7­III­ 1984 (J.B. Whitfield). OREGON: Cannon Beach, 3 females, 2 males, 9­VIII­1940 (H.&.M. Townes). Seaside, 1 female, 7­VIII­1940 (H.&M. Townes). Waldport, 1 female, 6­VIII­1953, ex Lithocolletis gaultheriella on salal (R.G. Rosenstiel), 1 female, 22­IV­ 1940, ex skeletonizers on Gaultheria shallon (K.Gray, J. Shuh) , 2 males, 1­V­1976 (H.&.M. Townes).

Holotype in CAS collection; paratypes in UCB, Oregon State University , AEI collections.

Hosts. Cameraria (?) sp. on Quercus wislizenii A.DC. , Cameraria gaultheriella Walsingham on Gaultheria shallon Pursh , and an undetermined skeletonizer on the undersides of Gaultheria leaves.

Comments. The size and distinctive, large ovipositor sheaths are the best characters for recognizing this species. In other features, P. powelli could be confused with P. bedelliae and P. thuiellae . It is interesting that this species also attacks at least one non­leafmining host, but on the same plant species as a leafmining host it attacks. This species was referred to as Pholetesor species 3 in Whitfield & Wagner (1988) and Gates et al. (2002).

Figures

FIGURES 22–26. Forewings of: 22, Pholetesor rhygoplitoides Whitfield; 23, P. bedelliae (Viereck); 24, P. powelli Whitfield; 25, P. variabilis Whitfield; 26, P.viminetorum(Wesmael).

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).