Synergus obtusilobae ( Ashmead, 1885 ), 1922

Lobato-Vila, Irene & Pujade-Villar, Juli, 2021, The genus Synergus Hartig (Hymenoptera: Cynipidae: Synergini) in the New World: a complete taxonomic revision with a key to species, Zootaxa 4906 (1), pp. 1-121 : 72-74

Synergus obtusilobae ( Ashmead, 1885)

( Figure 28 )

Ceroptres obtusilobae Ashmead, 1885 . Trans. Am. Entomol. Soc. 12: 300. Type material: USNM.

Synergus obtusilobae: Weld (1922) . Proc. U. S. Nat. Mus. 61: 26.

Type material of Ceroptres obtusilobae Ashmead, 1885 (examined). LECTOTYPE ♀ with the following labels: ‘Jacksnvile Fla’ (white label) / ‘Type No 14537 U.S. N.M.’ (red label) / ‘Collection Ashmead’ (white label) / ‘ Ceroptres obtusilobae Ash’ (white label, handwritten) / ‘USNMENT 00802224’ (white label, QR code) / ‘ Lectotype ♀ Ceroptres obtusilobae Ashmead, 1885 IL-V desig-2017’ (red label) / ‘ Synergus obtusilobae (Ashmead) Weld, 1922 ’ (white label). PARALECTOTYPE (1♀) with the following labels: ‘Jacksnvile Fla’ (white label) / ‘ Paratype No 14537 U.S. N.M.’ (red label) / ‘Collection Ashmead’ (white label) / ‘ Paralectotype ♀ Ceroptres obtusilobae Ashmead, 1885 IL-V desig-2017’ (red label) / ‘ Synergus obtusilobae (Ashmead) Weld, 1922 ’ (white label).

Other material examined (3♂ & 9♀). Material deposited in USNM with the following labels: ‘Ironton Mo. Det 178’ (white label) / ‘403’ (white label, handwritten) / ‘ Synergus obtusilobae (Ashm.) ’ (white label with a black frame, handwritten) (1♀); ‘HopkUS 13685 E’ (white label, handwritten) / ‘Reared July 2–19’ (white label) / ‘ Quercus alba ’ (white label) / ‘Falls Church, Va’ (white label) / ‘Middleton Wm Col’ (white label) / ‘ Synergus obtusilobae (Ashm) det. Weld 1937’ (white label with a black frame, handwritten) / ‘USNMENT 00960844’ (white label, QR code) (1♀); same data, but with the following USNMENT codes: 00960069 (♂), 00960338 (♂), 000960528 (♀), 00960560 (♀), 0960684 (♀), 00960790 (♀), 00960802 (♀), 00960809 (♂); ‘HopkUS 13685 E’ (white label, handwritten) / ‘Reared May 9–18’ (white label) / ‘ Quercus minor (white label) / ‘L. H. Weld collector’ (white label) / ‘Ex. 525’ (white label, handwritten) / ‘ Synergus obtusilobae Ash. , det. Weld’ (white label with a black frame, handwritten) / ‘USNMENT 00960817’ (white label, QR code) (1♀); ‘Washngtn DC area’ (white label) / ‘JCBridwell coll 1939’ (white label) / ‘ Synergus obtusilobae Ashm. , det. Weld’ (white label with a black frame, handwritten) (1♀).

Diagnosis. Synergus obtusilobae belongs to a group of species characterized by having the mesopleuron entirely sculptured, including the speculum; hyaline wings and radial cell of fore wing at least 2.7 times as long as wide; POL usually longer than OOL; F1 and F2 equal or subequal, antenna 14-segmented in females; notauli complete, reaching the posterior margin of pronotum; circumscutellar carina weak; tarsal claws bidentate; first metasomal segment completely sulcate dorsally and laterally; and syntergum posteriorly with a band of micropunctures. Synergus obtusilobae differs from the rest of species of this group ( S. colombianus , S. dawnus , S. personatus , sp. nov., S. rufinotaulis , S. forcadellae , S. compressus , sp. nov. and S. filicornis ) by having the syntergum posteriorly with a complete wide band of micropunctures extending laterally 1/2 of its length (incomplete or complete band extended at most 1/ 3 in the rest of species); radial cell of fore wing 3.2 times as long as wide (2.7–3.0 in the rest of species); and head of females completely yellow, except for some dark spots close to ocelli (at least with frons, vertex and occiput black, with face and gena more or less yellowish in the rest of species).

Redescription

FEMALE. Length. Body length 3.5–4.0 mm (n = 11).

Color ( Fig. 28 ). Yellow to yellowish brown (ochre). Head yellow with some dark areas surrounding the ocelli. Antenna yellow. Mesosoma, especially mesoscutum and mesoscutellum, dark yellow. Metasoma yellow. Legs yellow, tibiae and metatarsi dark brown to black. Wings hyaline, veins dark brown.

Head. In frontal view ( Fig. 28c ) subtrapezoid, about 1.2 times as wide as high, gena not broadened behind eye. Face faintly pubescent, lower face with striae radiating from clypeus. Clypeus indistinct, ventral margin slightly projected over mandibles. Malar space about 0.6 times as long as height of eye. Anterior tentorial pits visible; pleurostomal and epistomal sulcus absent. Transfacial line about as long as height of eye. Toruli situated mid-height of eye; distance between torulus and eye about as long as diameter of torulus; distance between toruli shorter than diameter of toruli. Frons coriaceous with scarce small punctures; frontal carinae narrow, branched in their whole length and reaching lateral ocelli. Head in dorsal view is about 2.0 times as wide as long. Vertex weakly wrinkled and with some punctures. POL: OOL: LOL = 15: 12: 8 and diameter of lateral ocelli, 6. Occiput coriaceous, without punctures.

Antenna ( Fig. 28b ). 14-segmented; long, filiform, not broadened apically; pubescence dense and short. Scape plus pedicel about as long as F1; pedicel about 1.5 times as long as wide; F1 about as long as F2, F2 and F3 subequal; the following segments progressively shorter. Last flagellar segment somewhat more than 4.0 times as long as wide and 1.2 times as long as F11.

Mesosoma. About 1.2 times as long as high in lateral view, including nucha, with short and not dense pubescence ( Fig. 28a ). Ratio of length of pronotum medially/laterally: 0.43. Pronotal plate indistinct. Lateral pronotum weakly wrinkled; lateral carina absent, lateral margins of pronotum rounded seen from above. Mesoscutum ( Fig. 28b ) about 1.2 times as wide as long, densely wrinkled to carinated; anterior parallel lines shallow, reaching somewhat more than 1/3 of the mesoscutum; notauli complete, but shallow and interrupted by carinae; median mesoscutal line absent; parapsidal lines inconspicuous. Mesoscutellum ( Fig. 28b ) about as long as wide, wrinkled; circumscutellar carina inconspicuous; scutellar foveae ovate, shallow, weakly sculptured bottom, the posterior margin not well defined and separated by a narrow carina. Mesopleuron finely, regularly and densely striated. Metapleural sulcus reaching 3/4 of mesopleural height. Propodeum pubescent and alutaceous; propodeal carinae straight and slightly convergent posteriorly. Nucha sulcate dorsally and laterally.

Legs. Tarsal claws with a strong basal lobe.

Wings. Fore wing pubescent with short marginal setae, about as long the body length ( Fig. 28a ). Radial cell closed, about 3.2 times as long as wide; areolet visible, basal vein not well pigmented. Rs+M visible, almost reaching the basal vein. Basal cell with sparsely spaced setae.

Metasoma. About as long as head plus mesosoma and about 1.2 times as long as high in lateral view ( Fig. 28a ). First metasomal segment sulcate dorsally and laterally. Syntergum smooth, anterolateral pubescence composed of a few setae and posteriorly with a wide band of micropunctures extended 1/2 of its length; dorsodistally incised, not pointed; following segments with minute micropunctures. Hypopygial spine almost 1.5 times as long as wide and with a few lateral setae; without apical setae.

MALE. Similar to female, except for the following: body length about 3.0 mm (n = 3). Antenna 15-segmented; F1 straight, weakly incised medially, segment under the incision short and not broadened, apically after the incision long and not broadened. Metasoma shorter than head plus mesosoma. Body darker than in females; frons, vertex, occiput, mesosoma (except pronotum) and metasoma, almost totally black.

Distribution. USA: Florida ( Ashmead 1885), Virginia, Washington D.C., and Missouri (authors).

Biology. Reared from an ‘unnamed gall’ on Q. stellata ( Ashmead 1885) . The non-type material presented here was reared from unknown galls; one specimen was obtained from galls on Quercus alba L. ( Quercus section) and another, from galls on Q. stellata , according to their labels.

Remarks. Synergus obtusilobae was described from 2♀ ( Ashmead 1885: 300), which have been located and examined. One of the females has been designated as lectotype of the type series.

Ashmead (1885) says females of S. obtusilobae have 13-segmented antenna, but all the examined females both from the type series and among the non-type specimens have 14-segmemted antenna.

Figures

FIGURE 28. Synergus obtusilobae (lectotype, USNMENT 00802224): a) lateral habitus; b) mesosoma in dorsal view; d) head in frontal view.