Neuroterus oblongifoliae Nicholls, Stone & Melika, 2021

Melika, George, Nicholls, James A., Abrahamson, Warren G., Buss, Eileen A. & Stone, Graham N., 2021, New species of Nearctic oak gall wasps (Hymenoptera: Cynipidae, Cynipini), Zootaxa 5084 (1), pp. 1-131 : 104-107

Neuroterus oblongifoliae Nicholls, Stone & Melika , sp. nov.

Figs. 381–393

urn:lsid:zoobank.org:act:8ED513D6-D491-4934-BB62-3EE873FE209F

Type material: HOLOTYPE female “ USA, Arizona, Molino Basin campground, Santa Catalina Mtns. , leg. J. Nicholls, 2008.04.09. Code AZ1872, spAZl17; ex Quercus oblongifolia ” . PARATYPES (7 females and 3 males): 2 female with the same labels as the holotype; 5 female and 3 male labelled as “ USA, Arizona, Molino Basin campground, Santa Catalina Mtns. , leg. J. Nicholls, 2008.04.09. Code AZ1877, ex Quercus oblongifolia ”. The holotype and one male paratype are deposited at the USNM , 7 female and 2 male paratypes at the PHDNRL .

Etymology. Named after the host plant, Q. oblongifolia .

Diagnosis. Neuroterus oblongifoliae belongs to Kinsey’s subgenus Diplobius . One other species, Neuroterus lamellae Weld, 1957 , is known from Arizona that induces galls in the form of integral leaf parenchyma thickenings ( Weld 1957b). However, the mesoscutum is delicately coriaceous in N. lamellae , while in N. oblongifoliae the mesoscutum is smooth to delicately alutaceous.

Description. Sexual female ( Figs. 381–383, 385, 387–392 ). Head and mesosoma black, metasoma brown; clypeus and malar space light brown; mandibles, maxillary and labial palpi yellow; antennae brown; legs light brown.

Head alutaceous, with sparse white setae, denser on lower face; rounded, as broad as high and as broad as width of mesosoma in frontal view; 2.1× as broad as long in dorsal view. Gena alutaceous, not broadened behind eye in frontal view, narrower than transverse diameter of eye in lateral view; malar space alutaceous, with delicate parallel striae radiating from clypeus and not reaching eye, malar sulcus present; eye 5.0× as high as length of malar space. Inner margins of eyes parallel. POL 2.2× as long as OOL, OOL 1.5× as long as diameter of lateral ocellus and slightly longer than LOL; all ocelli ovate, of same size. Transfacial distance slightly greater than height of eye; diameter of antennal torulus slightly longer than distance between them, distance between torulus and eye slightly longer than diameter of torulus; lower face and slightly elevated median area uniformly alutaceous, without striae. Clypeus slightly broader than high, alutaceous; ventrally rounded, not emarginate, without median incision and with a few long setae; anterior tentorial pit large, rounded, epistomal sulcus distinct, broad, clypeo-pleurostomal line indicated by slightly impressed line. Frons and slightly elevated interocellar area alutaceous, with a few short white setae, with impressed rounded area above torulus; with smooth glabrous area below central ocellus. Vertex, occiput, postocciput, postgena alutaceous, with a few setae; occipital foramen nearly as high as height of postgenal bridge; hypostomal carina emarginate, continuing into indistinct postgenal sulci which are not united; postgenal bridge anteriorly as broad as occipital foramen. Antenna longer than head+mesosoma, with 12 flagellomeres, pedicel 1.2× as long as broad, F1 2.5× as long as pedicel and 1.5× as long as F2; F2 slightly longer than F3, all subsequent flagellomeres nearly equal in length, placodeal sensilla on F2–F12.

Mesosoma longer than high, with a few white setae. Propleuron alutaceous, with delicate rugae along sides. Pronotum alutaceous, with a few setae and irregular delicate striae laterally; anterior margin deeply invaginated, smooth, not foveolate. Mesoscutum delicately alutaceous, with a few setae, longer than broad (greatest width measured across mesoscutum at level of base of tegulae), emarginate posterolaterally, slightly elevated above dorsal axillar area. Notaulus, anterior parallel line, parapsidal line, median mesoscutal line absent; circumscutellar carina narrow, reaching above tegulae. Transscutal articulation absent. Mesoscutellum slightly longer than broad, ovate, gradually narrowing towards posterior end, alutaceous on sides, with smooth, glabrous disk and with a few scattered white short setae, posteriorly rounded, clearly overhanging metanotum. Mesoscutellar foveae in the form of a transverse, very narrow impressed anterior area, with smooth, glabrous bottom. Mesopleuron and speculum alutaceous, glabrous, invaginated in lower half; mesopleural triangle smooth, glabrous, with a few white setae and delicate longitudinal striae; dorsal and lateral axillar areas alutaceous, glabrous; subaxillular bar smooth, glabrous, at posterior end shorter than height of metanotal trough; metapleural sulcus reaching mesopleuron below half height, upper part of sulcus indistinct. Metascutellum smooth, glabrous, as high as height of smooth, glabrous ventral impressed area; metanotal trough smooth, glabrous; propodeum posterodorsally smooth, glabrous, with a few carinae present only at most posterior end of propodeum. Nucha short, smooth, glabrous. Tarsal claws simple, without basal lobe.

Forewing longer than body, hyaline, margin with long dense cilia, with black veins, radial cell open, 4.1× as long as broad; R1 and Rs nearly reaching wing margin; areolet large, triangular, well-delimited, Rs+M distinct along entire length, reaching basalis at lower 1/3 of its height.

Metasoma as long as head+mesosoma, saddle-shaped, taller than long in lateral view; second metasomal tergite extending to half the length of metasoma in dorsal view, with rare white setae anterolaterally, without micropunctures, subsequent tergites smooth, glabrous, without micropunctures. Hypopygium without micropunctures, prominent part of ventral spine of hypopygium short, as long as broad in ventral view, without setae. Body length 1.8–2.0 mm (n = 6).

Male ( Figs. 384, 386 ). Similar to female but eyes and ocelli larger, silvery; eye as high as length of transfacial distance and 4.4× as high as length of malar space, interocellar area strongly elevated, clypeus larger, yellow; antenna with 12 flagellomeres (suture between F12 and F 11 in some paratypes indistinct), scape, pedicel and F1 light brown, all subsequent flagellomeres dark brown, F1 straight, broadened apically, placodeal sensilla on F2– F13. Body length 1.7–2.0 mm (n = 3).

Gall. ( Fig. 393 ). An integral leaf gall visible as a 2–3 mm thickening of the leaf lamina, sometimes spanning the whole width of the leaf, more usually on one side of midrib, green underneath, pink or red on upper surface. Multilocular.

Biology. Only a sexual generation is known, which induces leaf galls on Q. oblongifolia . Galls mature in April, adults emerge soon afterwards. Some of the examined specimens came from a rearing that accidentally contained some other galls, so the morphological assessment of their identity was confirmed with DNA data. Cytb sequences from three individuals differed by between 0 and 0.69% (GenBank OK346315 – OK346317 ), while ITS2 sequences from two individuals were identical ( OK350667 – OK350668 ).

Distribution. USA, Arizona, Santa Catalina Mountains.

Figures

FIGURES 381–387. Neuroterus oblongifoliae Nicholls, Stone & Melika, sp. nov., sexual generation. 381–383, head, female: 381, frontal view, 382, dorsal view, 383, posterior view. 384, head, male, frontal view. 385–386, antenna: 385, female, 386, male. 387, mesosoma and propleura, frontal view, female.

FIGURES 388–391. Neuroterus oblongifoliae Nicholls, Stone & Melika, sp. nov., sexual generation, female. 388–389, mesosoma: 388, lateral view, 389, dorsal view. 390, metascutellum and propodeum, posterodorsal view. 391, metasoma, lateral view.

FIGURES 392–393. Neuroterus oblongifoliae Nicholls, Stone & Melika, sp. nov., sexual generation. 392, forewing, female. 393, galls.