Synergus atripes Gillette, 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 : 20-22

Synergus atripes Gillette, 1896

( Figure 4 )

Synergus atripes Gillette, 1896 . Trans. Am. Entomol. Soc. 23: 96. Type material: USNM.

Type material (examined). LECTOTYPE ♀ with the following labels: ‘Colo 1880’ (orange label) / ‘Type’ (white label, handwritten) / ‘ Paratype No. 27933 U.S. N.M.’ (red label) / ‘ AccNo 71950 USNM to be loaned only to ColoAgCol’ (white label) / ‘ Synergus atripes n. sp. Gill.’ (white label with a red frame, handwritten) / ‘USNMENT 00779910’ (white label, QR code) / ‘ Lectotype ♀ Synergus atripes Gillette, 1896 , IL-V desig-2017’ (red label). PARALECTOTYPES (4♂ & 2♀) with the following labels: ‘Colo 1880’ (orange label) / ‘Type’ (white label, handwritten) / ‘Collection Ashmead’ (white label) / ‘ Allotype No. 27933 U.S. N.M.’ (red label) / ‘ Synergus atripes Gill. ♂’ (white label, handwritten) / ‘USNMENT 00960072’ (white label, QR code) / ‘ Paralectotype ♂ Synergus atripes Gillette, 1896 , IL-V desig-2017’ (red label) (1♂); ‘Colo 1880’ (orange label) / ‘Type’ (white label, handwritten) / ‘Collection Ashmead’ (white label) / ‘ Paratype No. 27933 U.S. N.M.’ (red label) / ‘USNMENT 00960196’ (white label, QR code) / ‘ Paralectotype ♀ Synergus atripes Gillette, 1896 , IL-V desig-2017’ (red label) (1♀); ‘Colo 440’ (orange label) / ‘Type’ (white label, handwritten) / ‘ Paratype No. 27933 U.S. N.M.’ (red label) / ‘ AccNo 71950 USNM to be loaned only to ColoAgCol’ (white label) / ‘USNMENT 00960453’ (white label, QR code) / ‘ Paralectotype ♂ Synergus atripes Gillette, 1896 , IL-V desig-2017’ (red label) (1♂); ‘Colo 1708’ (white label) / ‘Type’ (white label, handwritten) / ‘Coll CF Baker’ (white label) / ‘ Paratype No. 27933 U.S. N.M.’ (red label) / ‘USNMENT 00960212’ (white label, QR code) (2♂) ; same data as the previous one, but USNMENT 00960056 (1♂) and with a red label ‘ Synergus atripes Gill. ’: 1♀ .

Diagnosis. Synergus atripes belongs to a group of species characterized by having the mesopleuron entirely sculptured, including the speculum, with non-parallel striae or wrinkles covering all of the surface, sometimes reticulated; hyaline wings and radial cell of fore wing short, 2.2 times as long as wide; mesoscutum strongly transversely carinated, interspaces sculptured; notauli visible but incomplete, not reaching the posterior margin of pronotum; mesoscutellum entirely carinated to wrinkled; and scutellar foveae inconspicuous to absent. Synergus atripes is morphologically close to S. batatoides (see below), from which differs by having frons and vertex sharply and finely striated, with striae running from toruli to lateral ocelli ( Fig. 4c ), vertex with small punctures (wrinkled and punctate, punctures on vertex stronger, in S. batatoides ); OOL 2.0 times as long as diameter of lateral ocelli ( Fig. 4c ) (1.5 in S. batatoides ); mesoscutum with strong, widely spaced transversal carinae ( Fig. 4b ) (strong but dense in S. batatoides ); tarsal claws with a strong basal lobe (very small in S. batatoides ); and in males, F1 2.0 times as long as F2, and F1 long, slightly curved and slightly expanded apically and basally (F1 1.5 times as long as F2 and F1 strongly curved, kidney shaped in males of S. batatoides ), among others (see the identification key).

Redescription

FEMALE. Length. Body length 2.0–3.0 mm (n = 3).

Color ( Fig. 4 ). Mainly black. Face and gena brownish orange, frons, vertex and occiput, black. Antenna yellow to testaceous. Mesosoma black, tegulae yellowish orange. Metasoma dark chestnut to reddish black. Legs with dark coxae, hind legs almost completely dark (except joints), first and second pair of legs mostly yellow except for some dark areas near joints. Wings hyaline, veins brown.

Head. In frontal view trapezoid, 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 just 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 slightly under mid-height of eye; distance between torulus and eye shorter than diameter of torulus; distance between toruli clearly shorter than diameter of toruli. Frons ( Fig. 4c ) sharply and finely striated beneath toruli, with striae running from toruli to lateral ocelli; without punctures. Head in dorsal view is about 2.3 times as wide as long. Vertex ( Fig. 4c ) finely striated and with scattered small punctures. POL: OOL: LOL = 14: 11: 8 and diameter of lateral ocelli, 5.5 ( Fig. 4c ). Occiput coriaceous, without punctures.

Antenna. 14-segmented; short, filiform, not broadened apically; pubescence dense and short. Scape plus pedicel about 1.3 times as long as F1; pedicel about 2.0 times as long as wide; F1 about 1.4 times as long as F2, F2 and F3 subequal, the following segments progressively shorter. Last flagellar segment about 3.0 times as long as wide and almost 2.0 times as long as F11.

Mesosoma. About 1.3 times as long as high in lateral view, including nucha, with short and not dense pubescence ( Fig. 4a ). Ratio of length of pronotum medially/laterally: 0.33. Pronotal plate indistinct. Lateral pronotum strongly carinated; lateral carina absent, lateral margins of pronotum rounded seen from above. Mesoscutum ( Fig. 4b ) about 1.2 times as wide as long, with strong and spaced carinae; anterior parallel lines inconspicuous; notauli incomplete, faint in the anterior 1/3, sometimes interrupted by carinae; median mesoscutal line absent; parapsidal lines weakly impressed, narrow, reaching tegulae. Mesoscutellum ( Fig. 4b ) rounded, about as long as wide, strongly carinated to wrinkled; circumscutellar carina weak, obscured by wrinkles, almost inconspicuous; scutellar foveae inconspicuous, obscured by wrinkles. Mesopleuron irregularly striated, striae non-parallel and well impressed, interspaces alutaceous. Metapleural sulcus reaching about 3/4 of mesopleural height. Propodeum pubescent and weakly sculptured; propodeal carinae straight and parallel. Nucha sulcate dorsally and laterally.

Legs. Tarsal claws with a strong basal lobe.

Wings ( Fig. 4a ). Fore wing pubescent with short marginal setae, about as long as body length. Radial cell closed, about 2.2 times as long as wide; areolet almost inconspicuous. Rs+M inconspicuous, not reaching the basal vein. Basal cell with sparsely spaced setae.

Metasoma ( Fig. 4a ). About as long as head plus mesosoma and about 1.3 times as long as high in lateral view. First metasomal segment usually with striae reaching only the half of its length, the anterior half smooth. Syntergum smooth, anterolateral pubescence composed of a few setae and posteriorly with a small patch of minute micropunctures (sometimes without punctures); not dorsodistally incised, slightly pointed. Hypopygial spine about 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 2.0– 2.5 mm (n = 4). Antenna 15-segmented; F1 almost 2.0 times as long as F2, slightly curved, medially incised, long, weakly broadened apically and basally. Malar space 0.5 times as long as height of eye. Metasoma shorter than head plus mesosoma.

Distribution. USA: Colorado ( Gillette 1896).

Biology. Reared from asexual galls of Atrusca brevipennata ( Gillette, 1893) ( Gillette 1896) .

Remarks. Synergus atripes was described from 6♂ and 10♀ ( Gillette 1896: 96). We located and examined 4♂ and 3♀ 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 A. brevipennata was collected from Q. x undulata , Q. gambelii , and Q. turbinella ( Burks 1979: 1093) .

Figures

FIGURE 4. Synergus atripes (lectotype, USNMENT 00779910): a) lateral habitus; b) mesosoma in dorsal view; c) head in anterodorsal view.