Andricus torreyaensis Melika & Abrahamson, 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 : 66-70

Andricus torreyaensis Melika & Abrahamson , sp. nov.

Figs. 235–255

urn:lsid:zoobank.org:act:273B953E-D3C9-41E9-92DE-6C067AE92575

Type material: HOLOTYPE female “ USA, Florida, Liberty Co., Torreya State Park , coll. 30 April 1995, adult emerged 12 May 1995, coll. G. Melika ; ex Quercus incana ” . PARATYPES: 14 females and 14 males: 5 females labelled as the holotype, 7 females and 14 males labelled as “ USA, Florida, Highlands Co., Archbold BioStation, leg. J. Nicholls, 2008.04.14. Code FL1055 , ex Quercus myrtifolia ” ; 2 females labelled as: “ USA, Florida, Highlands Co., Archbold BioStation , leg. J. Nicholls, 2008.04.19. Code FL1053 , ex Quercus myrtifolia ”. The holotype , 3 females and 3 males are deposited at the USNM , 11 females and 11 males and galls at the PHDNRL .

Etymology. The species is named after one of the sites where it was found, Torreya State Park.

Diagnosis. The gall resembles that of Zapatella quercusmedullae ( Ashmead, 1885) , but the morphology of adults is very different from that of Zapatella species. This species was also compared with species of the newly erected genus Melikaiella , and again the morphology of adults differs from that of Melikaiella species. Three Callirhytis species , C. quercusscitula ( Bassett, 1864) , sexual generation only; C. seminosa ( Bassett, 1890) , asexual generation only; C. quercuspunctata ( Bassett, 1863) , asexual generation only are known to induce similar stem swelling galls, however all three species are found further north and are unknown in Florida. In female specimens of C. quercusscitula and C. seminosa the head is transverse, dark brown; antenna stout, short; notaulus much broader posteriorly; the prominent part of the ventral spine of hypopygium only 2.5× as long as broad in ventral view. Callirhytis quercuspunctata is entirely black, the head transverse, the gena is strongly broadened behind the eye while A. torreyaensis is brown, with the gena only slightly broadened behind eye in frontal view.

Description. Sexual female ( Figs. 235–238, 243 , 245–251 ). Head and mesosoma brown, metasoma slightly darker; mandibles, maxillary and labial palpi, legs yellow.

Head delicately coriaceous, with sparse white setae; 1.2× as broad as high and slightly broader than mesosoma in frontal view, 1.8× as broad as long from dorsal view. Gena delicately coriaceous, slightly broadened behind eye in frontal view, as broad as transverse diameter of eye in lateral view. Malar space delicately coriaceous, with few striae radiating from clypeus and nearly reaching eye; eye 2.3× as high as length of malar space. Inner margins of eyes converging ventrally. POL 1.4× as long as OOL; OOL 1.9–2.1× as long as diameter of lateral ocellus and 1.8× as long as LOL; ocelli slightly elongated, of same size. Transfacial distance 1.2× as long as height of eye; diameter of antennal torulus 1.9× as long as distance between them, distance between torulus and eye slightly longer than diameter of torulus; lower face delicately coriaceous, without striae radiating from clypeus; slightly elevated median area delicately coriaceous. Clypeus smooth, glabrous, rectangular, at least 2.0× as broad as high; ventrally not emarginate, without median incision and with a few long setae; anterior tentorial pit large, rounded, epistomal sulcus and clypeo-pleurostomal line distinct. Frons and slightly elevated interocellar area delicately coriaceous, without striae, with a few short white setae. Vertex, occiput, postocciput, postgena delicately coriaceous, with sparse white setae; posterior tentorial pit large, ovate, area below impressed; occipital foramen as high as height of postgenal bridge; hypostomal carina emarginate, continuing into postgenal sulci which are not united, running parallel in ventral 2/3 of postgenal bridge, diverge in anterior 1/3, postgenal bridge anteriorly as broad as occipital foramen. Antenna longer than head+mesosoma, with 11 flagellomeres (suture between F12 and F11 invisible), pedicel longer than broad; F1 1.4× as long as pedicel and 1.2× as long as F2, F2 1.2× as long as F3, subsequent flagellomeres shorter, F11 2.0× as long as F10, placodeal sensilla on F2–F11.

Mesosoma longer than high, with sparse short white setae. Pronotum smooth and glabrous, with irregular striae laterally; propleuron smooth, glabrous. Mesoscutum uniformly delicately coriaceous, with a few white setae; slightly longer than broad (greatest width measured across mesoscutum at level of base of tegulae). Notaulus complete, reaching pronotum, distinctly and broadly impressed in posterior half, less impressed in anterior half, posteriorly converging; anterior parallel line short, delimited by slightly elevated lines in anterior 1/3; parapsidal line distinct, broad, marked by smooth glabrous area; median mesoscutal line in the form of a short triangle; circumscutellar carina narrow, reaching notaulus. Mesoscutellum slightly longer than broad, trapezoid, with subparallel sides, slightly broadened in posterior 1/3, posteriorly rounded, uniformly rugose, overhanging metanotum. Mesoscutellar foveae transverse, 2.0× as broad as high, with smooth, glabrous bottom, separated by narrow elevated coriaceous central carina. Mesopleuron uniformly rugose, mesopleural triangle smooth, glabrous, with a few rare setae; dorsal and lateral axillar areas smooth, glabrous, with white short setae; subaxillular bar smooth, glabrous, triangular, posterior end as high as height of metanotal trough; metapleural sulcus reaching mesopleuron in upper 1/3 of height, upper part of sulcus indistinct. Metascutellum coriaceous, as high as height of smooth, glabrous ventral impressed area; metanotal trough smooth, glabrous, with few setae; central propodeal area lyre-shaped, smooth, glabrous, with a few irregular rugae; lateral propodeal carina bent outwards in posterior 1/4; lateral propodeal area smooth, glabrous, with long white dense setae. Nucha with longitudinal sulci dorsally and laterally. Tarsal claws simple, without basal lobe.

Forewing longer than body, hyaline, margin with long dense cilia, veins brown, radial cell open, 3.4× as long as broad, R1 and Rs nearly reaching wing margin, areolet triangular, well-delimited, Rs+M distinct on 2/3 of distance to basalis, its projection reaching basalis at mid height.

Metasoma slightly longer than head+mesosoma, higher than long in lateral view; second metasomal tergite extending to half length of metasoma in dorsal view, with few short white setae anterolaterally, second to fifth tergites smooth, without punctures, subsequent tergites with micropunctures. Hypopygium with micropunctures, prominent part of ventral spine of hypopygium 4.0× as long as broad in ventral view, with short setae ventrally. Body length 2.1–2.4 mm (n = 6).

Male ( Figs. 239–242, 244 ). Similar to female but body predominantly black, transfacial distance as long as height of eye, eye 3.0× as high as length of malar space; POL 2.5× as long as OOL, OOL equal in length to diameter of lateral ocellus and as long as LOL, ocelli larger, ovate; antenna yellow, with 14 flagellomeres, F1 straight, apically not swollen; F13 as long as F12; placodeal sensilla on all flagellomeres. Body length 2.0– 2.2 mm (n = 10).

Gall. ( Figs. 252–255 ). A shoot swelling just behind the bud. The galls are multilocular, usually terminal, cylindrical swellings, 5– 9 mm in diameter and 10–22 mm in length, hard and woody when mature. The leaf buds on the gall can continue to grow after the gall has begun to develop, and ultimately cover the gall with leaves. Usually two to three neighboring twigs or buds are attacked, creating small clusters of two or three, sometimes four galls. The shape of the swelling differs slightly on different oak hosts.

Biology. Only a sexual generation is known, which induces stem swelling galls on Q. incana , Q. inopina , Q. laevis , Q. laurifolia , Q. myrtifolia , and Q. nigra . Galls mature in April-May, and adults emerge soon afterwards.

The conspecific status of males and females, plus specimens collected from different oak hosts at different locations was confirmed with DNA data. Two females and one male had cytb sequences that differed by between 0 and 1.85% (GenBank OK346292 – OK346294 ); while one male and one female had identical ITS2 sequences except for an additional T insertion in one sequence ( OK350655 – OK350656 ).

Distribution. USA, Florida: Torreya State Park, Archbold Biological Station, Jacksonville, Lake Manatee State Park.

Figures

FIGURES 235–244. Andricus torreyaensis Melika & Abrahamson, sp. nov., sexual generation. 235–238, head, female: 235, frontal view, 236, dorsal view, 237, posterior view, 238, lateral view. 239–242, head, male: 239, frontal view, 240, dorsal view, 241, posterior view, 242, lateral view. 243–244, antenna: 243, female, 244, male.

FIGURES 245–249. Andricus torreyaensis Melika & Abrahamson, sp. nov., sexual generation, female. 245, mesosoma and propleura, frontal view, 246, mesoscutum, dorsal view, 247, mesoscutellum, dorsal view, 248, mesosoma, lateral view, 249, metascutellum and propodeum, posterodorsal view.

FIGURES 250–255. 250–251, Andricus torreyaensis Melika &Abrahamson, sp. nov., sexual generation, female.250, forewing, part, 251, metasoma, lateral view. 252–255, galls on different host oaks: 252, Q. incana, 253, Q. inopina, 254, Q. laurifolia, 255, Q. myrtifolia.