Ceroptres frondosae 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 : 28-29

Ceroptres frondosae Ashmead, 1896

( Figures 3 i–k; 6f, g)

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

Type material (examined). LECTOTYPE (♀) with the following labels: ‘ Through C. V. Riley’ (white label) / ‘ Type No. 3283 U.S. N.M.’ (red label) / ‘ Ceroptres frondosae ♀ Ashm’ (white label, handwritten) / ‘ Lectotype ♀ Ceroptres frondosae Ashmead, 1896 , IL-V desig-2019’ (red label).

Additional material. 1♂ of Ceroptres frondosae deposited in USNM in the same pin and with the same data as the lectotype .

Diagnosis. Ceroptres frondosae is morphologically almost identical to C. cornigera (see above), from which differs only by having POL about 3.0 times as long as OOL ( Fig. 3k ) (POL 2.0 times as long as OOL in C. cornigera , Fig. 3g ) and OOL about as long as diameter of lateral ocelli ( Fig. 3k ) (OOL 1.5 times as long as diameter of lateral ocelli in C. cornigera , Fig. 3g ). It also has a medial ridge in the depressed area delimited by the two vertical carinae on the lower face ( Fig. 3j ) like C. cornigera and C. ensiger (see the diagnosis of C. cornigera ).

Redescription. Female. Length. Body length 2.6 mm (n=1).

Color ( Figs 3i ; 6f, g ). Black. Head, mesosoma and almost the entire metasoma, black; tegulae yellow, metasomal terminal segments and hypopygium, reddish brown or black. Antennae and legs testaceous, coxae dusky at base. Wings hyaline, veins pale yellow.

Head. In anterior view ( Fig. 3i ) trapezoid-shaped, about 1.3 times as wide as high, genae not expanded behind compound eyes. Face with long and moderately dense pubescence, lower face with short striae radiating from sides of clypeus, not reaching the toruli nor the ventral margin of compound eyes; medially without striae; vertical carinae incomplete, running from inner ventral margin of the toruli almost 2/3 of the lower face length and delimiting a depressed area that is bulged medially, forming a medial ridge ( Fig. 3j ). Clypeus distinct, not projected over mandibles. Malar space almost 0.5 times as long as height of compound eye. Anterior tentorial pits visible; pleurostomal sulcus absent, epistomal sulcus slightly impressed. Transfacial line about 0.9 times as long as height of compound eye. Toruli situated mid-height of compound eye; distance between torulus and compound eye slightly shorter than diameter of the toruli; distance between the toruli clearly shorter than diameter of the toruli. Front finely coriaceous to alutaceous, with small scarce piliferous punctures; without frontal carinae. Head in dorsal view ( Fig. 3k ) is about 2.3 times as wide as long. Vertex finely coriaceous to alutaceous, with small scarce piliferous punctures. POL:OOL: LOL = 18:6:7 and diameter of lateral ocelli about as long as OOL. Occiput finely coriaceous to alutaceous.

Antennae ( Fig. 6f ). 12-segmented; filiform, not broadened apically; pubescence dense and short. Scape plus pedicel about 1.3 times as long as F1; pedicel 1.3 times as long as wide; F1 0.9 times as long as F2, F2 and F3 subequal, the following segments progressively shorter. Last flagellar segment about 4.0 times as long as wide and 2.5 times as long as F9.

Mesosoma. About 1.2 times as long as high in lateral view ( Fig. 6f ), including nucha, with long, but not dense, pubescence. Ratio of length of pronotum medially/laterally: 0.38. Dorsal part of pronotal plate complete, with two distinct but small widely spaced foveae. Lateral pronotum coriaceous to imbricated, without lateral carina. Mesoscutum ( Fig. 6g ) 1.1 times as wide as long, strongly coriaceous with weak discontinuous transversal elements; anterior grooves weakly impressed, extending 1/3 of the mesoscutal length. Notauli almost complete and well impressed, but faint in the anterior 1/3, wider posteriorly. Parapsidal grooves shallow, surpassing tegulae. Median groove short, narrow and shallow, visible at most in the posterior 1/4 of the mesoscutum. Mesoscutellum ( Fig. 6g ) rounded, about as long as wide, densely but weakly wrinkled, more strongly wrinkled laterally and posteriorly, interspaces strongly coriaceous; circumscutellar carina absent; scutellar foveae ovate, shallow, not well defined posteriorly, weakly sculptured and separated by a narrow carina. Mesopleuron ( Fig. 6f ) smooth and shiny, little pubescent basally. Metapleural sulcus reaching about 3/4 parts of the mesopleural height. Propodeum pubescent and smooth; propodeal carinae straight and almost parallel. Nucha weakly sculptured dorsally and laterally, not sulcate.

Legs. Tarsal claws bidentate, with a basal lobe.

Wings ( Fig. 6f ). Forewings pubescent with short marginal setae, about as long as body length. Radial cell closed, 2.7 times as long as wide; areolet not well defined, anterior and basal veins inconspicuous. Rs+M inconspicuous. Basal cell with sparsely spaced setae.

Metasoma ( Fig. 6f ). Slightly 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, 0.3 times as long as the metasomal length and with a dense hair patch anterolaterally. Third metasomal tergum with an inconspicuous posterodorsal patch of micropunctures, not dorsodistally incised; subsequent terga very finely punctate. Prominent part of the hypopygial spine about as long as wide and slightly projected.

Male. Similar to female, except for the following morphological traits: body length 1.7 mm (n=1). Antennae with an unknown number of segments (broken); F1 slightly curved and expanded apically. Vertical carinae on the lower face shorter.

Distribution. USA. Saint Louis, state of Missouri ( Ashmead 1896; Burks 1979).

Biology. Reared from galls of Cynips ? quercusfrondosa Bassett, 1864 (unplaced species by Burks (1979: 1107) since Bassett (1864: 688) described only the gall), which associates with Quercus prinoides Willd. (= Q. chinquapin Pursh. ) ( Quercus section ) according to Bassett (1864). Galls of Cynips ? quercusfrondosa have ‘cone-like body, developed from the axillary leaf-buds, and covered when green and often when dry with a dense, rose-like cluster of imperfectly developed leaves’ according to Bassett (1864: 688).

Remarks. Ceroptres frondosae was originally described from 3♀ ( Ashmead 1896: 186). We only located and examined 1♀ deposited in USNM. We also found a male mounted alongside the lectotype belonging to the same species. According to the original description, Ashmead did not find any male of C. frondosae , so it is possible he confused the sex of this specimen. In any case, since Ashmead did not describe the male of Ceroptres frondosae it cannot be considered as part of the type series.

Similarities and differences between C. frondosae and C. cornigera and the possibility they are the same species have been discussed in the remarks section of C. cornigera .

Figures

FIGURE 3. Female faces of valid species of Ceroptres: a) C. catesbaei (type); b) C. cerri; c) C. clavicornis; d) C. confertus (type); e) C. cornigera (type); f) detail of the median ridge in the lower face of C. cornigera; g) head of C. cornigera in dorsal view; h) C. ensiger; i) C. frondosae (type); j) detail of the median ridge in the lower face of C. frondosae; k) head of C. frondosae in dorsal view.

FIGURE 6. a) Ceroptres cornigera lateral and b) dorsal habitus (type); c) C. ensiger lateral habitus, d) detail of mesopleuron and e) dorsal habitus (type); f) C. frondosae lateral and g) dorsal habitus (type); h) head and mesosoma of C. kovalevi in lateral view, i) lateral metasoma and j) head and mesosoma in dorsal view (type).