Neuroterus nervus Pujade-Villar & Bravo-Cuautle, 2025

Bravo-Cuautle, Samay, Pérez-Torres, Betzabeth C., Aragón-García, Agustín, Cuesta-Porta, Víctor & Pujade-Villar, Juli, 2025, Description of Neuroterus nervus Pujade-Villar & Bravo-Cuautle sp. nov. (Hymenoptera, Cynipidae) associated with Quercus glaucoides in Puebla State (México), Zootaxa 5689 (3), pp. 592-600 : 593-597

Neuroterus nervus Pujade-Villar & Bravo-Cuautle , sp. nov.

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( Figs 1–4 )

Type material. HOLOTYPE sexual female preserved in ethanol, deposited in JP-V coll. ( UB), with the following labels: Jardín Botánico de Puebla ( MEX), Q. glaucoides , ( 29.vi.2024) 15-31.vii.2024 (white label); Holotype Neuroterus nervus JP-V & Bravo-Cuautle n. sp., desig. JP-V 2025 (red label) . PARATYPES 3♂ & 4♀ with the same labels as holotype (preserved in ethanol), deposited in JP-V coll. ( UB) .

Additional material. Jardín Botánico de Puebla ( MEX), Q. glaucoides , ( 13.vii.2024) 15-31.vii.2024: 4♂ & 2♀ ( 1♀ & 1♂ mounted, dry). Deposited in JP-V coll. ( UB) .

Etymology. Referring to the location of the gall of this sexual form on the leaf vein.

Diagnosis. The new species aligns with the subgenus Dolichostrophus by the 13 antennomeres and the differential coloration of males and females, males lighter, with yellow colorations, and females darkbrown to black as in N. clarkeae Beutenmüller, 1910 , N. contortus ( Weld, 1921) , N. congregatus Gillette, 1893 , N. dubius Bassett, 1900 , N. fragilis Bassett, 1900 , N. minutus ( Bassett, 1881) , N. quercusbatatus ( Fitch, 1859) , N. quercusirregularis (Osten Sacken, 1861) , N. quercicola Dalla Torre, 1892 , N. saltatorius ( Edwards, 1874) , and N. washingtonensis Beutenmüller, 1913 . However, N. nervus sp. nov. differs from all the species of this subgenus by the lack of a malar sulcus. Only two species with a sexual form are known for Mexico: Neuroterus fusifex and Neuroterus chinatenco . The female of Neuroterus nervus Pujade-Villar & Bravo-Cuautle , sp. nov. lacks the malar sulcus while in the other sexual species from Mexico the malar sulcus is present. Moreover, the male of Neuroterus nervus Pujade-Villar & Bravo-Cuautle , sp. nov. is light brown (yellowish in N. fusifex and N. chinatenco ). Finally, the gall of the new species is inconspicuous on the underside of the midrib of leaves while in N. fusifex and N.chinatenco the gall is very visible and located on the leaf blade.

Description.

Sexual Female. Body length 1.1–1.2 mm (n = 4).

Color ( Fig. 4e ). Body dark brown to black.Scape, pedicel and basal part of F1 yellowish, remaining flagellomeres darker. Mandibles yellowish with black tooth. Legs yellow except for the coxae and femur and tibia III which have some light brown areas. Forewings hyaline with brown veins.

Head ( Figs 1a, 1c ) 2.0× times as wide as long in dorsal view, transversely oval in frontal view, 1.1× as high as broad; as broad as mesosoma in dorsal view. Lower face reticulated with sparse and scarce setae, central area bulging. Vertex, frons and face uniformly reticulated; vertex and frons glabrous. Clypeus trapezoidal, as wide as high, polished, moderately pubescent, ventral margin rounded and projecting over mandibles; median area of clypeus with alutaceous sculpture; lateral and ventral projecting areas smooth. Anterior tentorial pits conspicuous; epistomal sulcus and clypeo-pleurostomal lines present but inconspicuous. Malar space around 0.25× the height of compound eye, malar sulcus absent, malar space with some weak irradiating carinae. The maxillary palps with four segments and labial palps with two. Transfacial line 0.9× as long as height of eye. Compound eyes slightly converging ventrally. Toruli located at above midline of head; diameter of antennal torulus 2.0× as long as distance between them; distance between torulus and eye as long as diameter of torulus. Ocellar plate not raised. POL 3.0× as long as OOL, OOL 2.0× as long as LOL; all ocelli ovate and of the same size. Vertex reticulated-imbricated.

Antenna ( Fig. 3b ) longer than head+mesosoma, with 11 flagellomeres; pedicel 2.1× as long as broad and longer than scapus; F1 1.7× as long as pedicel and 1.6× as long as F2; F2 as long as F3; F3 1.2× as long as F4; F4 to F8 similar in length; F9 and F10 slightly shorter than F11 and subequal. Relative lengths of antennal segments: 7:11:19:12:12:10:10:10:10:10:8:8:9. Placodeal sensilla very sparse, present on F2 to F11.

Mesosoma ( Figs 2a–c ). Around 1.5× as long as broad in dorsal view, 1.3× as long as high in lateral view and with dorsal margin flat. Pronotum alutaceous. Mesoscutum alutaceous with very few sparse setae in the notauli area. Notauli absent, anterior parallel and parapsidal lines absent. Transcutellar suture absent. Scutellum nearly circular or very slightly longer than broad, pointed distally, around 0.6× as long as mesoscutum, alutaceous on dorsal surface and disk sparsely pubescent, circumscutellar carina absent. Scutellar foveae absent. Scutellum not overlapping metascutelum posteriorly in lateral view. Mesopleuron alutaceous, mesopleural triangle absent. Metapleural sulcus poorly defined reaching half the height of the mesopleura. Metascutellum alutaceous, subrectangular. Propodeum alutaceous and very scarcely pubescent, setae longer on the sides; lateral propodeal carinae absent, nucha short alutaceous. Metanotal fovea large, sculptured and pubescent.

Legs. Tarsal claws simple, without a basal lobe or tooth.

Forewing ( Fig. 3a ). 1.2× as long as body, hyaline, setose; apical margin with a fringe of long setae. Radial cell 4.1× as long as broad, open along anterior margin, areolet triangular, closed and distinct; R1 and Rs not reaching margin of wing; Rs expanded at apex and continuing slightly parallel to the margin; Rs+M complete but faint, reaching the basal vein below the midpoint. First abscissa of radius (2r) curved. Basal cell glabrous and costal cell setose. Metasoma. Shorter than head + mesosoma combined, as long as high in lateral view. All metasomal tergites smooth, glabrous, second metasomal tergum extending to 2/3 length of metasoma in dorsal view, with very few and sparse short white setae anterolaterally; all terga and hypopygium without micropunctures, prominent part of ventral spine of hypopygium short, as long as broad in ventral view ( Fig. 2d ); lateral margins of hypopygial spine with setae, the subapical ones slightly projected over apical end of the spine, without forming a tuft.

Male

( Figs. 1b, 1d , 4d )

Similar to female except in lighter brown body colour, head darker; antennae yellow on the pedicel, scape and F1, the rest of flagellomeres yellowish to light brown; legs yellowish. Malar space strongly reduced, 0.14× height of eye, transfacial distance short, around 0.8× as long as height of eye. POL 3.5× as long as OOL; OOL 1.5× as long as LOL and shorter than diameter of lateral ocellus; all ocelli ovate and of the same size; ocellar area elevated; antenna as long as head+mesosoma, with 12 flagellomeres; F1 hardly curved and broadened distally, 1.2× as long as pedicel and 1.8× as long as F2; following segments decreasing in length; antennal formula 12:15:30:17:17:17:16:16:16:16: 14:14:14:15; mesoscutum alutaceous, more conspicuous than in female. Length: 1.0– 1.1 mm (n = 3)

Galls ( Fig. 4a–c ). Multilocular gall, located on the midrib of leaves, causing hypertrophy of the vein, being more prominent on the lower side of the leaf. The gall is not covered by any pubescence. The color is green when immature and woody brown when mature. Laval chambers oval, with the same orientation as midrib, around 1.0– 1.2 mm x 0.5–0.6 mm.

Biology. Neuroterus nervus sp. nov. induces galls on Q. glaucoides Mart & Gal. (section Quercus ), and only the sexual form is known. The galls were collected at the end of June and early July and the adults emerged in the second half of July. The exit holes are located on the underside of the gall. This gall is attacked by undetermined Tetrastrichinae.

Distribution. Mexico, only known in Puebla State.

Figures

FIGURE 1. Neuroterus nervus sp. nov.: (a) female head in dorsal view, (b) female head in frontal view, (c) male head in dorsal view, (d) male head in frontal view.

FIGURE 2. Neuroterus nervus sp. nov., female: (a) mesosoma in dorsal view, (b) head and mesosoma in lateral view, (c) propodeum, (d) ventral spine of hypopygium.

FIGURE 3. Neuroterus nervus sp. nov.: (a) fore wing, (b) female antenna, (c) male antenna, with detail of the first segments.

FIGURE 4. Neuroterus nervus sp. nov.: (a-c) galls, (d) male habitus, (e) female habitus.