Synergus virentis ( 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 : 97-99

Synergus virentis ( Ashmead, 1885)

( Figure 39 )

Ceroptres virentis Ashmead, 1885 . Trans. Amer. Entomol. Soc. 12: 300. Type material: USNM.

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

Type material of Ceroptres virentis Ashmead, 1885 (examined). LECTOTYPE ♀ with the following labels: ‘Jacksnville, Fla’ (white label) / ‘Type’ (white label) / ‘Type No. 14536, U.S. N.M.’ (red label) / ‘Collection Ashmead’ (white label) / ‘ Ceroptres virentis Ashm ♀, Type’ (white label, handwritten) / ‘USNMENT 00802411’ (white label, QR code) / ‘ Lectotype ♀ Ceroptres virentis Ashmead, 1885 , IL-V desig-2017’ (red label) / ‘ Synergus virentis (Ashmead) Weld, 1922 , IL-V det. 2017’ (white label). PARALECTOTYPES (1ϐ & 1♀) with the following labels: ‘Jacksnville, Fla.’ (white label) / ‘Collection Ashmead’ (white label) / ‘ Paratype No. 14536, U.S. N.M.’ (red label) / ‘USNMENT 00960472’ (white label, QR code) / ‘ Paralectotype Ceroptres virentis Ashmead, 1885 , IL-V desig- 2017’ (red label) / ‘ Synergus virentis (Ashmead) Weld, 1922 , IL-V det. 2017’ (white label).

Diagnosis. Synergus virentis belongs to a group of species characterized by having the mesopleuron entirely sculptured, covered with fine, regular and dense transversal striae, the speculum medially finely aciculate to almost smooth; hyaline wings and radial cell of fore wing at least 2.5 times as long as wide; mesoscutum coriaceous, imbricated or weakly and densely transversely carinated; notauli incomplete, not reaching the posterior margin of pronotum; scutellar foveae visible and traceable, either well defined or shallow; and first metasomal segment completely sulcate dorsally and laterally. Synergus virentis differs from the rest of species of this group ( S. ebenus and S. ruficephalus ) by having head, mesosoma and metasoma mostly ochre or amber, antenna yellow and legs pale yellow in both sexes ( Fig. 39 a–c) (black or at least with some dark surfaces, never entirely yellow, ochre or amber in these species); gena slightly broadened behind eye (not broadened in these species); frons and vertex alutaceous to finely coriaceous, without punctures nor wrinkles ( Fig. 39b ) (finely coriaceous with some small punctures, sometimes also with very weak wrinkles in these species); frontal carinae very short, running just a little from toruli, obscured by antenna (absent in these species); F1 and F2 subequal in females, at most 1.2 in males (at least 1.3 in females, 2.0 in males); and syntergum posteriorly with a wide band of micropunctures occupying almost 1/3 of its length (just with a posterodorsal patch in these species).

Redescription

FEMALE. Length. Body length about 2.0 mm (n = 2).

Color ( Fig. 39 ). Body mainly yellowish brown (ochre). Face and gena, yellow; frons, vertex and occiput, ochre. Antenna yellow. Mesosoma ochre; tegulae, yellow. Metasoma yellowish orange, amber. Legs pale yellow. Wings hyaline, veins pale yellow.

Head. In frontal view ( Fig. 39c ) subtrapezoid to rounded, 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 straight, not 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 slightly longer than 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 finely coriaceous, without punctures; frontal carinae short, obscured by antenna, almost inconspicuous. Head in dorsal view is about 2.4 times as wide as long. Vertex ( Fig. 39b ) finely coriaceous, without punctures. POL: OOL: LOL = 13.5: 10: 6 and diameter of lateral ocelli, 5.5. Occiput finely coriaceous, without punctures.

Antenna. 14-segmented; filiform, not broadened apically; pubescence dense and short. Scape plus pedicel about as long as F1; pedicel about 1.8 times as long as wide; F1 about as long as F2 or just slightly longer, F2 and F3 subequal; the following segments progressively shorter. Last flagellar segment almost 4.0 times as long as wide and 1.6 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. 39a ). Ratio of length of pronotum medially/laterally: 0.36. Pronotal plate indistinct. Lateral pronotum imbricated to weakly carinated; lateral carina absent, lateral margins of pronotum rounded seen from above. Mesoscutum ( Fig. 39b ) about 1.2 times as wide as long, imbricated, more strongly sculptured posteriorly, interspaces alutaceous; anterior parallel lines weakly impressed, almost inconspicuous; notauli incomplete, faint in the anterior 1/3; median mesoscutal line absent; parapsidal lines weakly impressed, almost inconspicuous. Mesoscutellum about 1.1 times as long as wide, wrinkled; circumscutellar carina weak but visible, obscured by wrinkles; scutellar foveae subtriangular, small, shallow, weakly punctate, posterior margin more or less defined and separated by a narrow carina. Mesopleuron ( Fig. 39a ) regularly striated basally, speculum finely aciculate, almost smooth. Metapleural sulcus reaching 4/5 of mesopleural height. Propodeum pubescent and weakly sculptured; propodeal carinae straight and parallel. Nucha sulcate dorsally and laterally.

Legs. Tarsal claws unknown (all the examined specimens have legs broken).

Wings. Fore wing pubescent with short marginal setae, slightly longer than the body length. Radial cell closed, about 2.5 times as long as wide; areolet visible, but only posterior vein slightly pigmented. Rs+M inconspicuous, not reaching the basal vein. Basal cell with sparsely spaced setae.

Metasoma. About as long as head plus mesosoma and 1.2 times as long as high in lateral view ( Fig. 39a ). First metasomal segment sulcate dorsally and laterally. Syntergum smooth, anterolateral pubescence composed of a few setae and posteriorly with a wide band of minute micropunctures extended almost 1/3 of its length; not dorsodistally incised, pointed; following segments with minute micropunctures. Hypopygial spine as long as wide and with a few lateral setae; without apical setae.

MALE. Similar to female, except for the following: antenna 15-segmented; F1 1.2 times as long as F2; F1 slightly curved and incised medially, slightly broadened basally and apically. Lower face less striated medially (or even without striae). Malar space 0.7 times as long as height of eye. Metasoma shorter than head plus mesosoma.

Distribution. USA: Florida ( Ashmead 1885).

Biology. Reared from galls of Disholcaspis quercusvirens ( Ashmead, 1881) ( Ashmead 1885; Weld 1951; Burks 1979).

Remarks. Synergus virentis was described from an unstated number of specimens ( Ashmead 1885: 300). We located and examined 1ϐ and 2♀ belonging to the type series deposited in USNM and designated one of the females as lectotype.

The host plant is not mentioned in the original description; however, S. virentis was probably collected from galls on Q. virginiana or Q. minima , because these are the only host trees mentioned for D. quercusvirens ( Weld 1951; Burks 1979; Melika et al. 2013).

Figures

FIGURE 39. Synergus virentis (lectotype, USNMENT 00802411): a) lateral habitus; b) head and mesosoma in dorsal view; c) head in frontal view.