Ceroptres minutissimi Ashmead, 1885

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 : 39-41

Ceroptres minutissimi Ashmead, 1885

( Figures 4c ; 7c, d ; 18o )

Ceroptres minutissimi Ashmead, 1885 . Trans. Am. Ent. Soc. 12: 301. Type material: USNM.

Type material (examined). LECTOTYPE (♀) with the following labels: ‘Jacksnville Fla’ (white label) / ‘Type’ (white label) / ‘ Ceroptres minutissimi ♀ Ashm.’ (white label, handwritten) / ‘USNMENT 00892586’ (white label, QR code) / ‘ Lectotype ♀ Ceroptres minutissimi Ashmead, 1885 , IL-V desig-2017’ (red label). PARALECTOTYPES (3♂ & 1♀) with the following labels: ‘Jacksnville Fla’ (white label) / ‘Type’ (white label) / ‘ Paralectotype Ceroptres minutissimi Ashmead, 1885 , IL-V desig-2017’ (red label) (2♂ & 1♀); ‘Jacksnville Fla’ (white label) / ‘Collection Ashmead’ (white label) / ‘ Type No. 2831 U.S. N.M.’ (red label) / ‘ Ceroptres minutissimi Ashm. ’ (white label, handwritten) / ‘ Paralectotype ♂ Ceroptres minutissimi Ashmead, 1885 , IL-V desig-2017’ (red label) (1♂).

Additional material (2♀). New material collected in Mexico and deposited in UB with the following location data: MEX: P233, Bosques de Santa Fe (Cuajimalpa, CDMX), 19°21’00.59” N, 99°16’25.38” W, Ex. unknown gall on leaves, 1571m, Q. rugosa , (28.vi.2016) vii.2016, JP-V leg.

Diagnosis. This species can be recognized by its small size (both females and males usually a little more than 1.0 mm long), its long hypopygium, which appears considerably projected above the upper surface of the metasoma and by having the pedicel almost 2.0 times as long as wide, being about as long as F1 (which is as long as F2 or just slightly shorter).

Redescription. Female. Length. Body length 1.0– 1.5 mm (n=4).

Color ( Figs 4c ; 7c, d ). Mainly brown to dark brown. Head and mesosoma brown to dark brown; tegulae yellow. Antennae yellow, the tip sometimes somewhat darker. Legs brownish yellow. Metasoma brown or dark brown, posteriorly darker. Wings hyaline, veins pale.

Head. In anterior view ( Fig. 4c ) round-shaped, almost 1.2 times as wide as high, genae not expanded behind compound eyes. Face with moderately long but not dense pubescence, lower face with short striae radiating from sides of clypeus and almost reaching the base of compound eyes; medially without striae; vertical carinae incomplete and weak, short, running just a little from inner ventral margin of the toruli and delimiting a small depressed area. Clypeus indistinct, not projected over mandibles. Malar space about 0.5 times as long as height of compound eye. Anterior tentorial pits visible; pleurostomal and epistomal sulcus absent. Transfacial line about 1.1 times as long as height of compound eye. Toruli situated below mid-height of compound eye; distance between torulus and compound eye about as long as diameter of the toruli; distance between the toruli shorter than diameter of the toruli. Front from finely coriaceous to alutaceous, apparently smooth, with neither punctures nor frontal carinae. Head in dorsal view ( Fig. 7d ) is about 2.0 times as wide as long. Vertex from finely coriaceous to alutaceous, apparently smooth, without punctures. POL:OOL:LOL = 9:4.5:4 and diameter of lateral ocelli, 2. Occiput finely coriaceous to alutaceous, apparently smooth, without punctures.

Antennae ( Fig. 7c ). 12-segmented; subclavate, just slightly broadened apically; pubescence dense and short. Scape plus pedicel almost 2.0 times as long as F1; pedicel 1.7 times longer than wide; F1 about as long as F2 or just slightly shorter, F2 and F3 subequal, the following segments progressively shorter. Last flagellar segment somewhat more than 3.0 times as long as wide and 2.3 times longer than F9.

Mesosoma. About 1.2 times as long as high in lateral view ( Fig. 7c ), including nucha, with moderately long, but not dense, pubescence. Ratio of length of pronotum medially/laterally: 0.3. Dorsal part of pronotal plate complete, with two distinct foveae. Lateral pronotum from finely coriaceous to alutaceous, without lateral carina. Mesoscutum ( Fig. 7d ) about 1.2 times as wide as long, finely coriaceous to alutaceous; anterior grooves very weakly impressed or inconspicuous. Notauli incomplete and weakly impressed, reaching at most the half of the mesoscutum. Parapsidal grooves weakly impressed or inconspicuous. Median groove very short and shallow, almost inconspicuous. Mesoscutellum ( Fig. 7d ) rounded, about as long as wide, weakly wrinkled, sometimes wrinkles only extended laterally and posteriorly, medially weakly sculptured; circumscutellar carina absent; scutellar foveae small, ovate, shallow, smooth and very close to each other, separated by a very narrow carina. Mesopleuron ( Fig. 7c ) smooth and shiny; little pubescent basally. Metapleural sulcus reaching about 4/5 parts of the mesopleural height. Propodeum pubescent, smooth; propodeal carinae straight and parallel. Nucha weakly sulcate dorsally and laterally.

Legs. Tarsal claws bidentate, with a small basal lobe.

Wings. Forewings pubescent with long marginal setae, slightly longer than body length. Radial cell closed, about 3.0 times as long as wide (slightly longer in some specimens); areolet not well defined, anterior and basal veins inconspicuous. Rs+M inconspicuous. Basal cell with sparsely spaced setae.

Metasoma ( Fig. 7c ). About as long as head plus mesosoma and slightly longer than high in lateral view. First metasomal tergum crescent-shaped and smooth. Second metasomal tergum short and free, about 0.3 times as long as the metasomal length and faintly pubescent anterolaterally. Third metasomal tergum without punctures and not dorsodistally incised. Subsequent terga, sparsely punctate. Hypopygium long and very projected above the upper surface of the metasoma. Prominent part of the hypopygial spine about as long as wide and just slightly projected.

Male. Similar to female, except for the following morphological traits: body length 0.8–1.2 mm (n=3). Antennae with 15 segments, filiform; F1 1.2 times longer than F2 and not excavated. POL:OOL:LOL = 8:4:4; OOL about as long as the diameter of lateral ocelli.

Distribution. USA (Jacksonville, state of Florida) ( Ashmead 1885; Burks 1979) and Mexico (state of Ciudad de México) (in this work, see the additional material).

Biology. Originally reared from galls of Neuroterus quercusminutissimus ( Ashmead, 1885) , which produces leaf galls on Quercus virginiana Mill. ( Quercus section ) according to Burks (1979). The new material collected from Mexico was obtained from undetachable galls on leaves of Q. rugosa Née ( Quercus section ) ( Fig. 18o ), probably belonging to Neuroterus .

Remarks. Ceroptres minutissimi was originally described from ‘many specimens’ ( Ashmead 1885: 301). We located and examined 3♂ and 2♀ deposited in USNM from Ashmead’s collection. Based on Ashmead’s description, there should be more specimens belonging to the type series.

According to Ashmead’s description, C. minutissimi is dark brown or shining black and females have 13-segmented antennae; however, all the specimens studied have a brown body (probably due to the passing of time in the case of the type specimens and due to intraspecific variability in the case of the new additional material), and both females from the examined type series and from the additional material have 12-segmented antennae.

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 7. a) Ceroptres lanigerae lateral and b) dorsal habitus (type); c) C. minutissimi lateral and d) dorsal habitus (type); e) C. montensis lateral and f) dorsal habitus (type); g) C. petiolicola lateral habitus, h) forewing and i) detail of mesoscutuellum and propodeum (type).

FIGURE 18. Some of the galls mentioned in this study: a) an undescribed species of Andricus (ref. 069); b) Sphaeroteras nr pulchripennis (ref. 103); c) Dros perlentum (ref. 123); d) Neuroterus eugeros (ref. 182); e) Andricus georgei (ref. 206); f) unknown leaf gall of Neuroterus (ref. 225); g) unknown leaf spherical gall (ref. 266); h) Andricus sphaericus (ref. 303); i) Andricus sphaericus (ref. 307); j) Andricus group georgei (ref. 312); k) Melikaiella amphibolensis (ref. 338); l) an undescribed species of Andricus on leaves (ref. P015); m) Atrusca sp. (ref. P149); n) unknown (P225); o) unknown undetachable leaf gall (ref. P233); p) unknown gall inside secondary leaf nerves (ref. P307); q) Atrusca pictor (ref. P322); r) Atrusca sp. (ref. P328); s) unknown (ref. 2B10, 13B6); t) unknown, a mix of galls (ref. 2840); u) unknown leaf petiole gall (ref. P366); v) unknown twig gall (ref. P308).