Ceroptres rufiventris Ashmead, 1896

Lobato-Vila, Irene & Pujade-Villar, Juli, 2019, Revision of world Ceroptresini (Hymenoptera: Cynipidae) with the description of a new genus and five new species, Zootaxa 4685 (1), pp. 1-67 : 51-52

Ceroptres rufiventris Ashmead, 1896

( Figures 4h ; 8g, h )

Ceroptres rufiventris Ashmead, 1896 . Trans. Am. Ent. Soc. 23: 186. Type material: USNM.

Type material (examined). HOLOTYPE (♀) with the following labels: ‘3190, Apr.19.83’ (white label, handwrit- ten) / ‘ Through C. V. Riley’ (white label) / ‘ Type No. 3284 U.S. N.M.’ (red label) / ‘ Ceroptres rufiventris Ashm. ’ (white label) / ‘ Holotype ♀ Ceroptres rufiventris Ashmead, 1896 ’ (red label).

Diagnosis. This species can be separated from the rest of Ceroptres by the following combination of morphological traits: female antenna 13-segmented and filiform (males unknown); vertical carinae on the lower face weak and incomplete, short; mesoscutum coriaceous; notauli almost complete, but faint in the anterior 1/3; median groove absent or very weakly impressed; mesoscutellum strongly wrinkled; scutellar foveae circular to ovate, large, shallow and separated by a narrow carina; third metasomal tergum with a small posterodorsal patch of micropunctures somewhat extended laterally; the subsequent terga and hypopygium also punctate; radial cell 2.7 times as long as wide; head and mesosoma reddish brown, metasoma rufous to amber (head and mesosoma black, and metasoma rufous according to the original description).

Redescription. Female. Length. Body length 2.0 mm (n=1).

Color ( Figs 4h ; 8g, h ). Reddish brown and rufous to amber. Head and mesosoma reddish brown, with small dark spots close to lateral ocelli; tegulae yellow. Antennae and legs, testaceous. Metasoma rufous to amber. Wings hyaline, veins pale yellow.

Head. In anterior view ( Fig. 4h ) trapezoid-shaped, about 1.2 times as wide as high, genae not expanded behind compound eyes. Face with long and moderately dense pubescence, lower face with long striae radiating from sides of clypeus, reaching the base of compound eyes and almost the toruli; medially without striae; vertical carinae weak and incomplete, short, running just a little from inner ventral margin of the toruli and delimiting a small depressed area. Clypeus distinct, not projected over mandibles. Malar space about 0.5 times as long as height of compound eye. Anterior tentorial pits visible; pleurostomal sulcus absent, epistomal sulcus slightly impressed. Transfacial line about as long as height of compound eye. Toruli situated mid-height of compound eye; distance between torulus and compound eye shorter than diameter of the toruli; distance between the toruli clearly shorter than diameter of the toruli. Front finely coriaceous to alutaceous, with some small piliferous punctures; without frontal carinae. Head in dorsal view is about 2.1 times as wide as long. Vertex finely coriaceous to alutaceous, without punctures. POL:OOL: LOL = 14:8:6 and diameter of lateral ocelli, 4. Occiput finely coriaceous to alutaceous, without punctures.

Antennae ( Fig. 8g ). 13-segmented; filiform, not broadened apically; pubescence dense and short. Scape plus pedicel about as long as F1; pedicel about 1.3 times as long as wide; F1 about 0.8 times as long as F2, F2 slightly longer than F3, the following segments progressively shorter. Last flagellar segment about 3.8 times as long as wide and 2.1 times as long as F10.

Mesosoma. About 1.1 times as long as high in lateral view ( Fig. 8g ), including nucha, with long, but not dense, pubescence. Ratio of length of pronotum medially/laterally: 0.46. Dorsal part of pronotal plate complete, with relatively big and closely spaced distinct foveae. Lateral pronotum alutaceous, without lateral carina. Mesoscutum ( Fig. 8h ) 1.2 times as wide as long, coriaceous; anterior grooves weakly impressed, extending 1/3 of the mesoscutal length. Notauli almost complete, but faint in the anterior 1/3, wider posteriorly. Parapsidal grooves weakly impressed, surpassing tegulae. Median groove very weakly impressed or absent. Mesoscutellum ( Fig. 8h ) slightly longer than wide, strongly wrinkled; circumscutellar carina absent; scutellar foveae circular to ovate, large, shallow, not well defined posteriorly and separated by a narrow carina. Mesopleuron ( Fig. 8g ) smooth and shiny; little pubescent basally. Metapleural sulcus not well defined, reaching about 4/5 parts of mesopleural height. Propodeum pubescent and weakly sculptured; propodeal carinae straight and parallel. Nucha weakly sculptured dorsally and laterally, not sulcate.

Legs. Tarsal claws bidentate, with a basal lobe.

Wings ( Fig. 8g ). Forewings pubescent with moderately long marginal setae, about as long as body length. Radial cell closed, 2.7 times as long as wide; areolet visible, veins weakly pigmented. Rs+M inconspicuous. Basal cell with sparsely spaced setae.

Metasoma ( Fig. 8g ). Shorter than head plus mesosoma and about as long as high in lateral view. First metasomal tergum crescent-shaped and smooth. Second metasomal tergum short and free, 0.4 times as long as the metasomal length and faintly pubescent anterolaterally. Third metasomal tergum with a small posterodorsal patch of micropunctures somewhat extended laterally, not dorsodistally incised; the subsequent terga and hypopygium, punctate. Prominent part of the hypopygial spine about as long as wide and not projected.

Male. Unknown.

Distribution. USA. Cadet, state of Missouri ( Ashmead 1896).

Biology. Reared from galls of Andricus quercusostensackenii (Bassett, 1863) , which produces leaf galls on Quercus coccinea Müenchh. and Q. palustris Müenchh. (Lobatae section) according to Burks (1979).

Remarks. Ceroptres rufiventris was originally described from a single female ( Ashmead 1896: 186), which has been located and examined.

According to Ashmead’s description, C. rufiventris has both head and mesosoma black, and metasoma rufous; however, the specimen studied has head and mesosoma reddish brown, and metasoma from rufous to amber. Since C. rufiventris seems to be well characterized by the descriptor, we believe that color differences between the original description and the type material studied are probably the result of a discoloration process.

Figures

FIGURE 4. Female faces of valid species of Ceroptres: a) C. kovalevi (type), discontinuous lines point out vertical carinae; b) C. lanigerae (type); c) C. minutissimi (type); d) C. montensis (type); e) C. petiolicola (type); f) C. pisum (type); g) C. quercusobtusilobae (type); h) C. rufiventris (type); i) C. snellingi (type).

FIGURE 8. a) Ceroptres pisum lateral and b) dorsal habitus, c) detail of female antenna and d) forewing (type); e) C. quercusobtusilobae lateral habitus and f) mesosoma in dorsolateral view (type); g) C. rufiventris lateral and h) dorsal habitus (type).