Pholetesor bedelliae (Viereck)

Whitfield, James B., 2006, Revision of the Nearctic species of the genus Pholetesor Mason (Hymenoptera: Braconidae), Zootaxa 1144 (1), pp. 1-94 : 40-42

Pholetesor bedelliae (Viereck)

( figs. 9 , 23 , 37 , 46 , 66 , 81 )

Apanteles (Protapanteles) bedelliae Viereck, 1911 . Proc. U.S. Nat. Mus. 40: 174. Holotype female, USNM No. 13501, examined.

Females. Body length 1.7–2.3 mm, forewing length 1.9–2.5 mm.

Head. Frons 1.3x broader at midheight than long down midline, weakly, shallowly punctate; inner margins of eyes weakly converging towards clypeus. Antennae dark brown throughout, slightly longer than body in dried specimens; all but distal 5–6 flagellomeres with 2 ranks of placodes; flagellomeres 2 3.4–3.6x longer than broad; flagellomere 14 1.2– 1.4x longer than broad. Palpi light yellow­brown. Head in dorsal view twice broader than long down midline.

Mesosoma . Mesoscutum in dorsal view about same width as head, shallowly punctate, becoming indistinctly punctate posteriorly near scutoscutellar scrobe; surface between punctures with weak metallic sheen. Scutoscutellar scrobe weakly arched medially, composed of fine, sharp punctures, usually set in transverse, weak depression. Scutellar disc smoother than mesoscutum, indistinctly punctate, very slightly longer than its maximum breadth. Metanotum weakly retracted from scutellum; sublateral setiferous lobes nearly appressed to hind margin of scutellum; transverse carinae at about midlength on either side poorly developed, at least laterally. Propodeum 1.9–2.1x broader than long at longest points, generally weakly punctate to rugulose except near nucha, from which radiate a series of short ridges; posterolateral corners nearly smooth.

Legs. Coloration decidedly variable; usually, prothoracic and mesothoracic legs light yellow­brown except darkened coxae, trochanters, tarsal apices and (mesothoracic legs) proximal portions of femora; metathoracic legs with coxae mostly dark brown to black, trochanters and femoral bases lighter brown, femora mostly light yellow­brown except dorsal infuscation near junction with tibiae, tibiae light yellow brown, darkening apically, tarsomeres conocolorous with darkened tibial apices. Hind femora occasionally nearly entirely darkened. Outer faces of hind tibiae with approximately 30 small, scattered spines. Inner hind tibial spur slightly longer than outer.

Wings. Tegulae dark brown, translucent. C+Sc+R, stigma, R1, 2r and 1Rs evenly deep brown, other venation more weakly pigmented, especially proximally; R1 slightly longer than stigma, about 3x as long as distance from its distal tip to end of 3Rs fold along wing edge; 2r and 1Rs generally about equal in length, meeting at more or less distinct angle (occasionally marked by a knob); 2r weakly arched. Vannal lobe of hindwing with short fringe over most of distal half.

Metasoma. Tergite I strongly rugose, 1.5–1.6x longer than basally broad, usually barrel­shaped in outline, broadest near midlength but sometimes broader apically or basally; anteromedial depression broad. Tergite II weakly aciculorugose, medially more aciculate, 1.9–22x as broad as medially long, often with weakly raised medial smoother region; anterolateral corners strongly rounded; posteriorly marked by straight to faintly bisinuate crenulate groove. Tergite III longer than II, with limited if any sculpturing. Laterotergites usually dark yellow­brown, rarely nearly as light in color as hind tibiae. Remaining terga of usual unsculptured, unmodified, overlapping form. Hypopygium about same length as hind basitarsus, submedially weakly creased, setting off translucent medial fold; tip bluntly acuminate. Ovipositor sheaths approximately same length as hind basitarsi, usually slightly shorter, broadest subapically, somewhat more convex ventrally than dorsally in profile, bluntly pointed, hairiest near tip. Ovipositor evenly decurved.

Males. Body length 1.6–2.2 mm, forewing length 1.9–2.4 mm. Males are usually easily associated with females, but could potentially be confused with males of P. thuiellae , P. rohweri and P. powelli . The first metasomal tergite is usually more strongly narrowed apically than in the females, and the second tergite is more transverse (2.3–2.6x as broad posteriorly as long down midline). The tibial and femoral coloration (especially in hind legs) is usually much darker than in sympatric females. There is a tendency for the forewing venation to be darker, especially in veins not strongly pigmented in the female. As in most Pholetesor males, the apical flagellomeres are more slender, with 2 ranks of placodes on all except the distal 3; the antennae are clearly longer than the body length.

Variation. In view of the broad geographical and host range of this species, it is not surprising that a great deal of intraspecific variability is expressed. Most of the specimens encountered should be recognizable on the basis of the above description; a few of the specimens reared from elachistids on grasses are significantly larger than usual and tend to have exceptionally broad first metasomal tergites and a long metacarp (R1). In general, most of the variation occurs in leg coloration, size, subtle differences in metasomal tergite shape and the configuration of veins 2r and 1Rs in the forewing, none of which is especially critical in recognizing this species.

Final instar larva. Labium with one pair of setae on short tubercles; maxillae each with one seta; mandibles set with 16–20 long teeth (not counting bifid tip).

Cocoon. White, elongate­oval with blunt ends, somewhat satiny with scattered loose exterior threads, spun on the undersides or bases of leaves, within the host mine (in the case of individuals attacking Phyllonorycter spp. ) or within the host cocoon (when emerging from Bucculatrix spp. or other Lyonetiidae ).

Material examined. Reared from Anomis erosa Huebner : 5 females, 1 male, Washington, DC (no date). Reared from Bedellia minor Busck : 3 females, 3 males, LOUISIANA, October. Reared from Bedellia somnulentella Zeller : 175 females, 126 males, CALIFORNIA, DISTRICT of COLUMBIA, IOWA, KANSAS, NEW JERSEY, OREGON, VIRGINIA, mostly August­December but some March, June, July. Reared from Bucculatrix canadensisella Chambers : 1 female, ONTARIO, August. Reared from Bucculatrix thurberiella Busck : 4 males, CALIFORNIA, September. Reared from Bucculatrix sp. on Amelanchier sp. : 1 female, NOVA SCOTIA, August. Reared from Bucculatrix sp. on Artemisia tridentata : 1 female, CALIFORNIA, July. Reared from Bucculatrix on Wyethia mollis : 1 female, 5 males, CALIFORNIA, August­September. Reared from Bucculatrix spp. (no plant given): 11 females, 1 male, ONTARIO, March (?), August­October. Reared from Caloptilia diversilobiella Opler on Rhus diversiloba : 2 males, CALIFORNIA, August. Reared from Caloptilia fraxinella (Ely) on Fraxinus sp. : 7 females, 8 males, ONTARIO, July–August. Reared from Caloptilia invariabilis (Braun) : 3 females, 5 males, ONTARIO, BRITISH COLUMBIA, June–July. Reared from Caloptilia negundella (Chambers) on Acer negundo : 2 females, 1 male, CALIFORNIA, July, October. Reared from Caloptilia sp. on Lithocarpus densiflorus : 2 females, 1 male, OREGON, June­July. Reared from Caloptilia sp. on Quercus nigra : 1 male, FLORIDA, August. Reared from Caloptilia spp. (no plant given): 3 females, 4 males, BRITISH COLUMBIA, OREGON, May, July. Reared from Cosmopterix sp. on morning­glory: 5 females, 2 males, Washington, DC, October. Reared from Elachista spp. on grasses and sedges (mostly undetermined plant spp.): 40 females, 31 males, CALIFORNIA, coastal­ February/March, Sierra­ September. Reared from Fenusa pusilla (probably mistaken host record): 1 female, QUEBEC, August. Reared from Leucoptera pachystimella Busck : 1 female, BRITISH COLUMBIA, late May. Reared from Micrurapteryx salicifoliella (Chambers) on Salix spp. : 5 females, 2 males, ONTARIO, August. Rerared from Phyllonorycter tremuloidella (Braun) : 2 males, ONTARIO, July. Reared from "sweet potato leafminers": 9 females, 7 males, southern CALIFORNIA, December. Not reared: 152 females, 98 males, distributed more or less throughout North America .

Hosts. I will not repeat the above list of hosts, except to comment that the records from Anomis erosa and Fenusa pusilla are probably in error; also, despite numerous rearings from leafminers on Colvolulaceae, I have been unable to confirm that P. bedelliae will parasitize Cosmopterix spp. It appears that the host range of this species is unusually broad; on many hosts, however, it is not a dominant parasitoid—perhaps its broad usual host and geographical ranges bring it into contact with a number of potential hosts which it only rarely parasitizes. In general, most of the hosts have in common a blotchmining habit in the shrub or ground layer of vegetation.

Comments. This is one of the most widespread, abundant and variable species in the genus. It is possible that more than one species is involved, but I am unable to consistently separate them morphologically. If any material here represents a separate species it will most likely be the individuals reared from elachistids on grasses and sedges.

P. bedelliae can be separated from P. thuiellae and P. powelli on the shortness and shape of the ovipositor sheaths (compare figures) and (to a lesser extent) the shorter metacarp (R1) in the forewing. Males of these three species are likely to be extremely difficult to associate with their respective females, without host data. Pholetesor variabilis and P. chiricahuensis are easily distinguished by their broader and narrower first metasomal tergites, respectively.

Figures

FIGURES 9–16. Cocoons of Pholetesor. 9: P. bedelliae (Viereck), on underside of leaf with Bedellia mine. 10: Cocoon of Bucculatrix albertiella on leaf of Quercus agrifolia; cocoon of P. bucculatricis (Muesebeck) is spun inside this cigar­shaped host cocoon. 11: P. salalicus (Mason) cocoon inside opened mine of Cameraria nemoris on Vaccinium ovatum. 12: P. salalicus cocoon inside opened mine of Cameraria gaultheriella on Gaultheria shallon. 13: Cocoon of P. caloptiliae Whitfield. 14: Cocoon of P. ornigis (Weed). 15: Cocoons of P. salalicus, showing varraiation in banding pattern. 16: Cocoon of P. salicifoliellae (Mason).

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 33–38. 33: metanotum of Pholetesor bucculatricis (Muesebeck), showing slight retraction from scutellum; 34: metanotum of P. salalicus (Mason), showing strong retraction from scutellum. Both FIGURES 400x. 35: propodeum and anterior metasomal tergites of P. bucculatricis (Muesebeck), dorsal view, 97.5x. 36: propodeum and anterior metasomal tergites of P. masoni Whitfield, dorsal view. 120x. 37: propodeum and anterior metasomal tergites of P. bedelliae (Viereck), dorsal view, 120x. 38: propodeum and anterior metasomal tergites of P. salalicus (Mason), dorsal view, 120x.

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).