Synergus atra 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 : 16-18

publication ID	https://doi.org/ 10.11646/zootaxa.4906.1.1
publication LSID	lsid:zoobank.org:pub:09383AAD-8E30-4E50-A533-C6DA4D00E33C
DOI	https://doi.org/10.5281/zenodo.4447507
persistent identifier	https://treatment.plazi.org/id/03BF702A-950A-FFD3-FDE5-FBE7710BFAD3
treatment provided by	Plazi
scientific name	Synergus atra Gillette, 1896
status

Treatment

( Figure 2 View FIGURE 2 )

Synergus atra Gillette, 1896 . Trans. Am. Entomol. Soc. 23: 86. Type material: USNM.

Type material (examined). LECTOTYPE ♀ with the following labels: ‘Mich’ (white label, handwritten) / ‘Gillette’ (white label, handwritten) / ‘Type’ (white label, handwritten) / ‘Type No. 27932 U.S. N.M.’ (red label) / ‘Acc- No71950 USNM to be loaned only to ColoAgCal’ (white label) / ‘ Synergus atra Gill. ’ (white label with a red frame, handwritten) / ‘USNMENT 00779906’ (white label, QR code) / ‘ Lectotype ♀ Synergus atra Gillette, 1896 , IL-V desig-2017’ (red label). PARALECTOTYPES (2♂ & 2♀) with the following labels: ‘Ag. Coll. Mich’ (white label, handwritten) / ‘Type’ (white label, handwritten) / ‘CollCF Baker’ (white label) / ‘ Synergus atra Gill’ (red label with a black frame, handwritten) / ‘ Paratype No. 27932 U.S. N.M.’ (red label) / ‘ Paralectotype ♂ Synergus atra Gillette, 1896 , IL-V desig-2017’ (red label) (1♂); ‘Mich’ (white label) / ‘C. P. Gillette’ (white label) / ‘Collection Ashmead’ (white label) / ‘ Allotype No. 27932 U.S. N.M.’ (red label) / ‘ Synergus atra Gill. ♂’ (white label, handwritten) / ‘ Paralectotype ♂ Synergus atra Gillette, 1896 , IL-V desig-2017’ (red label) (1♂); ‘Manitou, Colo.’ (white label, handwritten) / ‘Type’ (white label, handwritten) / ‘CollCF Baker’ (white label) / ‘Weld thinks this cannot be a type’ (white label, handwritten) / ‘ atra Gill. ’ (white label, handwritten) / ‘ Paralectotype ♀ Synergus atra Gillette, 1896 , IL-V desig-2017’ (red label) (1♀); ‘Biol. 117’ (white label) / ‘Type’ (white label, handwritten) / ‘Collection Ashmead’ (white label) / ‘ Paratype No. 27932 U.S. N.M.’ (red label) / ‘USNMENT 00960061’ (white label, QR code) / ‘ Paralectotype ♀ Synergus atra Gillette, 1896 , IL-V desig-2017’ (red label) (1♀).

Diagnosis. Synergus atra belongs to a group of species characterized by having the mesopleuron entirely sculptured, including the speculum, without smooth areas; hyaline wings and radial cell of fore wing at most 2.5 times as long as wide; POL longer than OOL; F1 longer than F2 and antenna of females with 13 segments; mesoscutum with transversal carinae, interspaces sculptured; notauli complete, reaching the posterior margin of pronotum; and syntergum without micropunctures posteriorly or just with a posterodorsal patch never laterally extended. This species differs from others belonging to this group ( S. bicolor , S. medullae , S. dimorphus , S. digressus , S. brevicornis and S. lignicola , see below) by having frons sharply and finely striated beneath toruli, with striae running from toruli towards lateral ocelli ( Fig. 2d View FIGURE 2 ) (coriaceous, weakly wrinkled and/or with punctures, but never with sharp striae in the rest of species); POL more than 2.0 times as long as OOL (less than 2.0 times in the rest of species); notauli complete but less impressed and interrupted by carinae anteriorly ( Fig. 2c View FIGURE 2 ) (complete and well defined in their entire length in the rest of species); metasoma, at least in females, as high as long in lateral view ( Fig. 2b View FIGURE 2 ) (longer than high in the rest of species); and male antenna with 14 segments (15 in the rest of species).

Redescription

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

Color ( Fig. 2 View FIGURE 2 ). Mainly dark brown to black. Frons, vertex and occiput dark brown to black, lower face and gena dark yellow to brownish orange with some black surfaces. Antenna yellow, the tip darker. Mesosoma completely dark brown to black, tegulae dark brown. Metasoma dark chestnut to reddish black. Legs testaceous to yellow, with some infuscate areas, coxae dark. Wings hyaline, veins pale yellow.

Head. In frontal view trapezoid, about 1.2 times as wide as high, gena slightly 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 slightly under mid-height of eye; distance between torulus and eye slightly longer than diameter of torulus; distance between toruli shorter than diameter of toruli. Frons sharply and finely striated beneath toruli, with striae running from toruli to lateral ocelli; without punctures ( Fig. 2d View FIGURE 2 ). Head in dorsal view is about 2.0 times as wide as long. Vertex finely striated, with scattered punctures ( Fig. 2d View FIGURE 2 ). POL: OOL: LOL = 11: 5: 5 and diameter of lateral ocelli, 3.5 ( Fig. 2d View FIGURE 2 ). Occiput slightly imbricated, with scattered punctures.

Antenna ( Fig. 2c View FIGURE 2 ). 13-segmented; short, filiform, not broadened apically; pubescence dense and short. Scape plus pedicel about 1.3 times as long as F1; pedicel almost 2.0 times as long as wide; F1 about 2.0 times as long as F2, F2 and F3 subequal, the following segments progressively shorter. Last flagellar segment about 2.5 times as long as wide and somewhat more than 2.0 times as long as F10.

Mesosoma. About 1.2 times as long as high in lateral view, including nucha, with short and not dense pubescence ( Fig. 2b View FIGURE 2 ). Ratio of length of pronotum medially/laterally: 0.31. Pronotal plate indistinct. Lateral pronotum strongly wrinkled; lateral carina absent, lateral margins of pronotum rounded seen from above. Mesoscutum ( Fig. 2c View FIGURE 2 ) about as wide as long, with dense and discontinuous weak carinae, interspaces coriaceous; anterior parallel lines weakly impressed, almost reaching 1/2 of the mesoscutum; notauli complete, but less impressed and visible anteriorly, somewhat interrupted by carinae; median mesoscutal line absent; parapsidal lines weakly impressed, reaching tegulae. Mesoscutellum ( Fig. 2c View FIGURE 2 ) rounded, about as long as wide, strongly carinated to wrinkled; circumscutellar carina weak but visible, somewhat obscured by wrinkles; scutellar foveae subtriangular, well impressed and delimited, the bottom weakly sculptured and separated by a narrow carina. Mesopleuron ( Fig. 2a View FIGURE 2 ) anteriorly reticulated, medially and basally more regularly striated, speculum finely striated; little pubescent basally. Metapleural sulcus reaching about 3/4 of mesopleural height. Propodeum pubescent and weakly sculptured; propodeal carinae straight and slightly convergent posteriorly. Nucha sulcate dorsally and laterally.

Legs. Tarsal claws with a small basal lobe.

Wings ( Fig. 2b View FIGURE 2 ). Fore wing pubescent with short marginal setae, slightly longer than body length. Radial cell closed, about 2.4 times as long as wide; areolet visible, but only the posterior vein well defined. Rs+M inconspicuous, not reaching the basal vein. Basal cell with sparsely spaced setae.

Metasoma. About as long as head plus mesosoma and about as high as long in lateral view ( Fig. 2b View FIGURE 2 ). First metasomal segment sulcate dorsally and laterally. Syntergum smooth, anterolateral pubescence composed of a few setae and with a small posterodorsal patch of minute micropunctures; not dorsodistally incised, very slightly pointed. Hypopygial spine about 3.0 times as long as wide and with a few lateral setae; without apical setae.

MALE. Similar to female, except for the following: body length 1.5 mm (n = 2). Antenna 14-segmented; F1 about 2.0 times as long as F2 (fully as long as F2 and F3 together), slightly curved, medially incised, long, more broadened apically than basally. Metasoma shorter and with a more widespread posterodorsal patch of minute micropunctures.

Distribution. USA: Michigan and Colorado ( Gillette 1896).

Biology. Reared from an unknown gall and from asexual galls of Disholcaspis rubens ( Gillette, 1893) ( Gillette 1896) .

Remarks. Synergus atra was described from 3♂ and 6♀ ( Gillette 1896: 86). We located and examined 2♂ 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 D. rubens galls were collected from several species of oaks from Quercus section ( Burks 1979: 1092): Q. arizonica , Q. x undulata , Q. qambelii , Q. oblongifolia , Q. rugosa , Q. turbinella , and Q. toumeyi .