Synergus atripennis Ashmead, 1896

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 : 18-20

Synergus atripennis Ashmead, 1896

( Figure 3 )

Synergus atripennis Ashmead, 1896 . Trans. Am. Entomol. Soc. 23: 189. Type material: USNM.

Type material (examined). LECTOTYPE ♀ with the following labels: ‘1657 June 28–83’ (white label, handwritten) / ‘ Type No. 3290 U.S. N.M.’ (red label) / ‘ Synergus atripennis Ashm. ’ (white label with a black frame, handwritten) / ‘USNMENT 00779908’ (white label, QR code) / ‘ Lectotype ♀ Synergus atripennis Ashmead, 1896 , IL-V desig-2017’ (red label). PARALECTOTYPES (3♀) with the following labels: ‘1657 June 28–83’ (white label, handwritten) / ‘ Type’ (white label) / ‘ Through C. V. Riley’ (white label) / ‘ Type No. 3290 U.S. N.M.’ (red label) ‘USNMENT 00960131’ (white label, QR code) / ‘ atripennis’ (white label, handwritten) / ‘ Paralectotype ♀ Synergus atripennis Ashmead, 1896 , IL-V desig-2017’ (red label) (3♀).

Diagnosis. Along with Synergus distinctus (see below), S. atripennis differs from the rest of species known within this genus from the New World by having smoky wings (commonly hyaline in Synergus ). Synergus atripennis differs from S. distinctus by having female antenna with 15 segments ( Fig. 3c ) (14 in S. distinctus , Fig. 12b ); vertex coriaceous, with small piliferous punctures ( Fig. 3c ) (wrinkled and with some punctures in S. distinctus , Fig. 12c ); mesopleuron with regular, dense and well-marked transversal striae covering all of the surface, except for a small aciculate, almost smooth, spot under the speculum ( Fig. 3a ) (with regular, widely spaced and well-marked transversal striae covering all of the surface in S. distinctus , Fig. 12b ); in females, syntergum strongly dorsodistally incised ( Fig. 3b ) (weakly to not dorsodistally incised in S. distinctus , Fig. 12a ); head amber, except frons, vertex and occiput, black ( Fig. 3 b–d) (black in S. distinctus , Fig. 12 b–c); and legs entirely amber ( Fig. 3b ) (coxae and trochanters mostly black in S. distinctus , Fig. 12b ).

Redescription

FEMALE. Length. Body length 3.5 mm (n = 4).

Color ( Fig. 3 ). Black and amber. Face and gena amber, frons, vertex and occiput, black. Antenna amber. Mesosoma completely black, tegulae yellowish orange. Metasoma, except the first segment, which is black, amber. Legs amber. Wings smoky, veins brown.

Head. In frontal view ( Fig. 3d ) trapezoid, just slightly wider than high, gena not broadened behind eye. Face faintly pubescent, lower face with striae radiating from clypeus. Clypeus indistinct, ventral margin just slightly projected over mandibles. Malar space about 0.5 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 shorter than diameter of torulus; distance between toruli shorter than diameter of toruli. Frons coriaceous, with scattered small piliferous punctures; frontal carinae narrow, branched before reaching lateral ocelli. Head in dorsal view ( Fig. 3c ) is about 2.5 times as wide as long. Vertex coriaceous, with scattered small punctures. POL: OOL: LOL = 16: 13: 9 and diameter of lateral ocelli, 8.5. Occiput coriaceous, without punctures.

Antenna ( Fig. 3c ). 15-segmented; long, filiform, not broadened apically; pubescence dense and short. Scape plus pedicel shorter than F1; pedicel about 1.3 times as long as wide; F1 about 1.2 times as long as F2, F2 and F3 subequal, the following segments progressively shorter. Last flagellar segment somewhat more than 3.0 times as long as wide and about 1.3 times as long as F12.

Mesosoma. About 1.2 times as long as high in lateral view, including nucha, with short and not dense pubescence ( Fig. 3b ). Ratio of length of pronotum medially/laterally: 0.42. Pronotal plate indistinct. Lateral pronotum strongly carinated; lateral carina absent, lateral margins of pronotum rounded seen from above. Mesoscutum ( Fig. 3c ) about 1.3 times as wide as long, with dense and discontinuous weak carinae; anterior parallel lines well defined, reaching 1/3 of the mesoscutum; notauli complete and well impressed; median mesoscutal line absent; parapsidal lines well impressed, reaching tegulae. Mesoscutellum ( Fig. 3c ) rounded, about as long as wide, strongly wrinkled; circumscutellar carina weak but visible, somewhat obscured by wrinkles; scutellar foveae large, circular to ovate, well impressed but posterior margin not well defined, the bottom weakly sculptured and separated by a narrow carina. Mesopleuron ( Fig. 3a ) more or less regularly striated, more strongly striated basally, medially with a small aciculate, almost smooth, spot; little pubescent basally. Metapleural sulcus reaching about 3/4 of mesopleural height. Propodeum pubescent and weakly sculptured; propodeal carinae straight and convergent posteriorly. Nucha sulcate dorsally and laterally.

Legs. Tarsal claws with a strong basal lobe.

Wings ( Fig. 3b ). Fore wing pubescent with moderately long marginal setae, about as long as body length. Radial cell closed, about 2.7 times as long as wide; areolet visible and well defined. Rs+M visible, not 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. 3b ). First metasomal segment sulcate dorsally and laterally. Syntergum smooth, anterolateral pubescence composed of a few setae and without punctures, following segments finely punctate; strongly dorsodistally incised, not pointed. Hypopygial spine about as long as wide and with a few lateral setae; without apical setae.

MALE. Unknown.

Distribution. USA: Florida ( Ashmead 1896).

Biology. Reared from asexual galls of Disholcaspis spongiosa (Karsch, 1880) (= Holcaspis quercusficula Bassett, 1881 ) ( Ashmead 1896).

Remarks. Synergus atripennis was described from 5♀ ( Ashmead 1896: 189). We located and examined 4♀ belonging to the type series deposited in USNM. A lectotype has herein been designated.

The host plant is not mentioned in the original description, but D. spongiosa galls were collected from Q. chapmanii and Q. stellata ( Burks 1979: 1093) .

Figures

FIGURE 3. Synergus atripennis (lectotype, USNMENT 00779908): a) mesopleuron; b) lateral habitus; c) head and mesosoma in dorsal view; d) head in frontal view.

FIGURE 12. Synergus distinctus (female paralectotype, Paratype No. 24502 USNM): a) detail of the metasomal punctuation; b) lateral habitus; c) mesosoma in dorsal view.