Neuroterus stonei Melika & Nicholls, 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 : 115-118

Neuroterus stonei Melika & Nicholls , sp. nov.

Figs. 422–434

urn:lsid:zoobank.org:act:99F7C43C-0EB1-409B-945B-E01A5BABF4E4

Type material: HOLOTYPE female “ USA, Arizona, Chiricahua Mtns. summit, leg. J. Nicholls, 2008.04.07. Code AZ1889, spAZb10; ex Quercus gambelii ” . PARATYPES (15 females and 15 males): 8 females and 10 males with the same labels as the holotype; 2 females “ USA, Arizona, 5 km N of Payson , leg. J. Nicholls, 2008.04.12. Code AZ1895, ex Quercus arizonica ” ; 5 females and 5 males “ USA, Arizona, 5 km NE of Strawberry , leg. J. Nicholls, 2008.04.12. Code AZ1854, ex Quercus gambelii ”. The holotype , 3 females and 3 males are deposited at the USNM , 12 females and 12 males at the PHDNRL .

Etymology. Named in recognition of the continuing contribution of Prof. Graham N. Stone (Institute of Evolutionary Biology, University of Edinburgh, UK) towards studies of oak gall wasps.

Diagnosis. Neuroterus stonei belongs to Kinsey’s subgenus Diplobius . The only other Neuroterus species that is known from the southwestern USA that induces bud galls in its sexual generation is N. alexandrae , although galls of that species have only been found to date on Q. tubinella while N. stonei galls the oaks Q. gambelii and Q. arizonica . In N. stonei the head is 2.2× as broad as long in dorsal view, the notaulus absent, the mesopleuron and speculum uniformly delicately coriaceous, the metasoma as long as head+mesosoma, as long as high in lateral view; in males POL 4.8× as long as OOL, while in N. alexandrae the head is 1.6× as broad as long in dorsal view, the notaulus is complete, marked with slightly impressed lines, the mesopleuron and speculum alutaceous, glabrous, the metasoma shorter than head+mesosoma, slightly longer than high in lateral view; in males POL 13.0× as long as OOL. Another species, N. rosieae , has parallel longitudinal striae on the metasoma but in N. stonei they are present only on the fifth tergum while in N. rosieae the entire metasoma is covered by parallel longitudinal striae.

Description. Sexual female ( Figs. 422–424, 427, 429–433 ). Head and mesosoma black, metasoma dark brown; mandibles, maxillary and labial palpi yellow; antennae dark brown, except light brown pedicel, F1 and F2; legs dark brown, with lighter tarsi.

Head alutaceous, with sparse white setae, denser on lower face; 1.2× as broad as high and slightly broader than mesosoma in frontal view, 2.2× 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 reaching eye, malar sulcus absent; eye 3.6× as high as length of malar space. Inner margins of eyes parallel. POL 3.0× as long as OOL; OOL as long as diameter of lateral ocellus and shorter than LOL; all ocelli ovate, of same size. Transfacial distance equal to height of eye; diameter of antennal torulus slightly shorter than distance between torulus and eye and slightly longer than distance between toruli; lower face and slightly elevated median area uniformly alutaceous, without striae. Clypeus trapezoid, alutaceous, slightly broader than high; ventrally rounded and emarginate, without median incision ventrally, with a few long setae ventrally; anterior tentorial pits large, rounded; epistomal sulcus invisible, clypeo-pleurostomal line distinct, broad. Frons and slightly elevated interocellar area alutaceous, with a few short white setae. Vertex, occiput, postocciput, postgena alutaceous, with some setae; occipital foramen higher than height of postgenal bridge; hypostomal carina emarginate, continuing into distinct postgenal sulci which curve outwards; postgenal bridge as broad as width of occipital foramen. Antenna longer than head+mesosoma, with 12 flagellomeres, pedicel subglobular; F1 1.9× as long as pedicel and 1.2× as long as F2, F2=F3, F3 slightly longer than F4, subsequent flagellomeres shorter, nearly equal in length; F12 slightly longer than F11, placodeal sensilla on F3–F12.

Mesosoma slightly longer than high, with a few white setae. Propleuron smooth, glabrous. Pronotum alutaceous, with a few setae and some delicate striae laterally; anterior margin invaginated, smooth, glabrous, foveolate. Mesoscutum alutaceous, with a few setae, longer than broad (greatest width measured across mesoscutum at level of base of tegulae). Notaulus, anterior parallel line, median mesoscutal line and parapsidal line absent; circumscutellar carina broad, reaching above tegula. Mesoscutum emarginate posterolaterally, slightly elevated above dorsal axillar area. Transscutal articulation absent. Mesoscutellum nearly as long as broad, rounded, uniformly delicately coriaceous, with some white short setae, strongly overhanging metanotum. Mesoscutellar foveae in the form of a transverse, ovate impressed anterior area, with alutaceous bottom. Mesopleuron and speculum uniformly delicately coriaceous, invaginated across lower half; mesopleural triangle smooth, glabrous, with a few white setae; dorsal and lateral axillar areas smooth, glabrous; subaxillular bar smooth, glabrous, with parallel margins, shorter than height of smooth, glabrous metanotal trough; metapleural sulcus distinct, reaching mesopleuron in lower half of its height, upper part of sulcus indistinct. Metascutellum smooth, glabrous, shorter than height of smooth, glabrous ventral impressed area; propodeum alutaceous, glabrous, with delicate striae in posterior section; central propodeal area alutaceous, lyre-shaped; lateral propodeal carinae complete, narrow, delicate. Nucha short, smooth, glabrous. Tarsal claws simple, without basal lobe.

Forewing longer than body, hyaline, with light brown veins, margin with long dense cilia, radial cell open, 4.0× as long as broad; R1 and Rs not reaching wing margin; areolet triangular, well-delimited, Rs+M distinct along full length, reaching basalis slightly below half its height.

Metasoma as long as head+mesosoma, as long as high in lateral view; second metasomal tergite extending to 1/5 the length of metasoma in dorsal view, with a few white setae anterolaterally, without micropunctures; third and fourth tergites smooth, glabrous, without micropunctures; fifth tergite with some delicate longitudinal striae. Hypopygium without micropunctures, prominent part of ventral spine of hypopygium slightly longer than broad in ventral view, with white setae ventrally. Body length 2.5–3.2 mm (n = 8).

Male ( Figs. 425–426, 428 ). Similar to female but height of eye 1.5× as long as length of transfacial distance; eye 6.9× as tall as length of malar space; POL 4.8× as long as OOL, OOL shorter than LOL; interocellar area strongly elevated in frontal view; antenna with 13 flagellomeres, F1 slightly curved and broader in distal half, longest flagellomere; F2 slightly longer than F3, subsequent flagellomeres shorter, nearly equal in length; placodeal sensilla on all flagellomeres. Body length 2.5–3.0 mm (n = 8).

Gall. ( Fig. 434 ). A small unilocular bud gall, spherical, reaching 4–5 mm diameter, that develop in terminal and lateral buds. The lower quarter to third of gall has a few bud scales around it. Gall is initially pale green with some darker green markings, becoming pinkish with darker red or purple lines as it matures. Similar in structure to the sexual generation of N. alexandrae on Q. turbinella . Possibly the same as the undescribed gall pictured in Fig. 22 of Weld (1960).

Biology. Only a sexual generation is known, which induces bud galls on Q. arizonica and Q. gambelii . Given the somewhat nondescript morphology of the gall, two females from different collection sites were sequenced for cytb and ITS2 to confirm the morphological assessment of species identity. The cytb sequences were identical, while ITS2 sequences differed by 0.38% with multiple insertions/deletions of one- or two-base repeat units (GenBank OK346324 – OK346325 , OK350669 – OK350670 ).

Distribution. USA, Arizona: Chiricahua Mountains, Mogollon Rim area south of Flagstaff.

Figures

FIGURE 434. Neuroterus stonei Melika & Nicholls, sp. nov., sexual generation, galls.

FIGURES 422–429. Neuroterus stonei Melika & Nicholls, sp. nov., sexual generation. 422–424, head, female: 422, frontal view, 423, dorsal view, 424, posterior view. 425–426, head, male: 425, frontal view, 426, dorsal view. 427–428, antenna: 427, female, 428, male. 429, forewing, part, female.

FIGURES 430–433. Neuroterus stonei Melika & Nicholls, sp. nov., sexual generation, female. 430–431, mesosoma: 430, dorsal view, 431, lateral view. 432, metascutellum and propodeum, posterodorsal view. 433, metasoma, lateral view

FIGURES 18–23. Andricus archboldi Melika & Abrahamson, sp. nov., asexual generation, female. 18–21, head: 18, frontal view, 19, dorsal view, 20, posterior view, 21, lateral view. 22, antenna. 23, forewing, part.