Andricus archboldi 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 : 8-14

Andricus archboldi Melika & Abrahamson , sp. nov.

Figs. 1–30

urn:lsid:zoobank.org:act:2EF886D5-46CC-47D2-8794-43BEB4CAC74D

Alternate sexual and asexual generations are known.

Etymology. Named after Mr. Richard Archbold (1907–1976), founder of the Archbold Biological Station (Lake Placid, Florida) in 1941.

Sexual generation

Figs. 1–17 , 29

Type material: HOLOTYPE female “ USA, Florida, Highlands Co., Lake Placid, Archbold Biological Station , ex Q. inopina , coll. G. Melika on 23–26 November 1994, emerge at the beginning of December 1994 ” . PARATYPES: 42 females and 10 males with the same labels as the holotype. The holotype, 6 females and 3 males are deposited at the USNM , 36 females and 7 males at the PHDNRL .

Diagnosis. No other gallers on Q. inopina and other red oaks in Florida induce a similar rounded, integral leaf gall, which is always pale yellow-green (in contrast to the darker green of the leaf) and located on the midrib. The sexual generation gall of Callirhytis quercuspunctata ( Bassett, 1863) is similar but occurs on red oak species distributed further north.

Description. Sexual female ( Figs. 1–4, 9 , 11–17 ). Head dark brown to black; mesosoma and metasoma entirely brown; mandibles light brown; maxillary and labial palpi light brown to yellow; antennae light brown to yellow; tegula yellow; legs yellow, with coxae slightly darker at the base; ventral spine of hypopygium yellow.

Head coriaceous, with scattered white setae, denser on lower face; slightly broader than high and slightly broader than mesosoma in frontal view, 1.9× as broad as long in dorsal view. Gena alutaceous, only slightly broadened behind eye, slightly narrower than transverse diameter of eye; malar space with distinct striae radiating from clypeus and reaching eye, malar sulcus absent; eye 2.8× as high as height of malar space. Eyes slightly converging ventrally. POL nearly 1.8× as long as OOL, OOL 2.6× as long as length of lateral ocellus, 1.3× as long as LOL, all ocelli of same size and shape. Transfacial distance 1.4x as long as height of eye, diameter of antennal torulus 2.2× as long as distance between them, distance between torulus and eye nearly equal to diameter of torulus; lower face with white setae and distinct short striae radiating from clypeus and reaching antennal toruli; slightly elevated median area smooth, glabrous. Clypeus rounded, coriaceous, glabrous; ventrally not emarginate and without median incision; anterior tentorial pit, epistomal sulcus and clypeo-pleurostomal line distinct, deep. Frons coriaceous with net of irregular delicate striae and a few white setae; interocellar area coriaceous, slightly elevated. Vertex, occiput, postocciput and postgena alutaceous, with sparse white setae; posterior tentorial pit large, ovate, deep, area below impressed; occipital foramen shorter than height of postgenal bridge; hypostomal carina emarginate, continuing into united postgenal sulci. Antenna slightly longer than mesosoma, with 13 flagellomeres; pedicel slightly longer than broad, F1 1.7× as long as pedicel and 1.2× as long as F2, F3=F4, F5–F12 nearly equal in length, F13 shorter than F12; placodeal sensilla on F2–F13.

Mesosoma 1.4× as long as high. Pronotum coriaceous, with net of irregular strong striae and some white setae laterally; propleuron alutaceous, glabrous, with delicately coriaceous area centrally. Mesoscutum reticulate, with few white setae; slightly longer than broad (largest width measured across mesoscutum at level of base of tegulae). Notaulus complete, deep, distinctly impressed, converging at posterior end; anterior parallel line impressed, extends to 1/3 of mesoscutum length; parapsidal line in the form of a smooth, glabrous line; median mesoscutal line absent. Transscutal articulation deep, distinct. Mesoscutellum quadrangular, uniformly reticulate, longer than broad, overhanging metanotum; mesoscutellar foveae not separated, in the form of a transverse semilunar impression along mesoscutum, with a smooth, glabrous bottom, with few longitudinal rugae. Mesopleuron rugose, with strong parallel waved transverse rugae at mid-height, with few white setae; speculum reticulate; mesopleural triangle rugose, with few setae; dorsal axillar area coriaceous, lateral axillar area reticulate, with a few white setae; subaxillular bar smooth, glabrous, with subparallel sides, most posterior part higher, as broad as height of metanotal trough; metapleural sulcus reaching mesopleuron at half height; upper part of sulcus absent. Metascutellum coriaceous, metanotal trough smooth, glabrous, with few short white setae; ventral impressed area as high as height of metascutellum, smooth, glabrous; central propodeal area smooth, glabrous, without rugae; lateral propodeal carinae strong, high, subparallel; lateral propodeal area rugose, with dense long, white setae. Nucha with irregular short sulci dorsally and laterally. Tarsal claws simple, without basal lobe.

Forewing longer than body, hyaline, with distinct long, dense cilia on margin, veins yellowish, radial cell open, 4.0× as long as broad; R1and Rs nearly reaching wing margin; areolet triangular, closed, distinct. Rs+M distinct on 2/3 of distance between areolet and basalis, its projection reaching basalis at mid height.

Metasoma slightly shorter than head+mesosoma, higher than long in lateral view; second metasomal tergite extending to 2/3 of length of metasoma in dorsal view, without white setae and micropunctures laterally, all subsequent tergites without setae, smooth, glabrous, with delicate rare micropunctures. Hypopygium with micropunctures, ventral spine of hypopygium short and broad, prominent part as long as broad, without setae. Body length 0.9–1.1 mm (n = 10).

Male ( Figs. 5–8, 10 ). Similar to female but ocelli slightly bigger, postgenal bridge longer than in female; antenna slightly longer than length of body, with 13 flagellomeres, F1 straight, apically slightly swollen, 1.3× as long as F2, placodeal sensilla on F2–F13. Body length 0.8–1.0 mm (n = 10).

Gall ( Fig. 29 ). Integral leaf galls, always on the midrib, ovoid 4–6 mm in diameter and protruding on both sides of the leaf lamina; pale yellow and contrasting with the darker green of the leaf. Usually one larva per gall, rarely two larvae.

Asexual generation

Figs. 18–28 , 30

Material examined. Eleven females “ USA, Florida., Highlands Co., Lake Placid, Archbold Biological Station, coll. G. Melika on 2 April 1995; adults dissected from galls the same day, ex Quercus inopina ”. Material deposited at the PHDNRL .

Diagnosis. Asexual females most closely resemble those of Callirhytis quercuscornigera ( Osten Sacken, 1865) . In A. archboldi the anterior half of the second metasomal tergite is brown and subsequent tergites are black, while in C. quercuscornigera the metasoma is uniformly brown. Galls of the asexual generation very closely resemble the galls of C. quercusclavigera ( Ashmead, 1881) , and C. quercuspunctata ; the former species is known to associate with Q. myrtifolia , a closely related species to Q. inopina . The galls of these three species are difficult if not impossible to distinguish. However, we never found the galls of A. archboldi on Q. myrtifolia . Furthermore, galls induced by C. quercuspunctata and C. quercusclavigera were never found on Q. inopina . Developing galls of C. quercusclavigera appear very similar to asexual galls of A. archboldi , however, at maturity the larval cells of C. quercusclavigera emerge through the bark of the gall and drop to the ground. The larval cells of A. archboldi remain inside the gall at maturity and the adults chew through the gall tissues to emerge.

Description. Asexual female ( Figs. 18–28 ). Head and mesosoma dark brown to black, clypeus, mandibles brown; maxillary and labial palpi, tegula yellow; antenna and legs light brown; metasoma light brown, tergites dorsally always darker.

Head coriaceous, with white setae, denser on lower face, 1.1× as broad as high and slightly broader than mesosoma in frontal view, 2.0× as broad as long in dorsal view. Gena coriaceous, broadened behind eye, 1.3× as broad as transverse diameter of eye; malar space coriaceous, with parallel striae radiating from clypeus and reaching eye; eye 2.1× as high as length of malar space. Eyes converging ventrally. POL 1.7× as long as OOL, OOL 1.9× as long as diameter of lateral ocellus, 1.4× as long as LOL, ocelli ovate, all three equal in size. Transfacial distance 1.2× as long as height of eye and 1.25× as long as height of lower face (distance between antennal rim and ventral margin of clypeus); diameter of antennal torulus 1.8× as long as distance between them, distance between torulus and eye 1.5× as long as diameter of torulus. Lower face rugose, without striae, with elevated median area and dense setae. Clypeus rectangular, flat, broader than high, alutaceous, ventrally rounded, not emarginate and not incised medially; with deep anterior tentorial pit, distinct epistomal sulcus and clypeo-pleurostomal line. Frons and interocellar area rugose with net of strong irregular rugae; vertex, occiput, postgena, postocciput coriaceous. Postocciput around occipital foramen impressed, smooth, glabrous, with parallel striae; posterior tentorial pit large, deep, elongate; hypostomal carina emarginate, continuing into postgenal sulci, postgenal bridge broader toward occipital foramen, 3.0× as high as broad; occipital foramen 2.5× as high as height of postgenal bridge. Antenna slightly longer than head+mesosoma, with 11 flagellomeres; pedicel 1.9× as long as broad, F1 1.6× shorter than length of scape+pedicel and slightly longer than F2, F3 1.2× as long as F2, F3 1.9× as long as F4, F5 slightly longer than F6, subsequent flagellomeres nearly equal in length, F11 1.7× as long as F10; placodeal sensilla in numerous rows on F4–F11.

Mesosoma longer than high in lateral view. Pronotum dull rugose, with white setae and distinctive subparallel striae laterally, emarginate along lateral edge. Mesoscutum uniformly reticulate, with a few white setae, nearly as long as broad (width measured across base of tegulae). Notaulus complete, reaching pronotum, uniformly deeply impressed along full length, with transverse parallel rugae on the bottom, converging posteriorly; median mesoscutal line deep, extending to 1/4 of mesoscutum length, with parallel transverse rugae on the bottom; anterior parallel line impressed, extends to half of mesoscutum length, smooth, glabrous; parapsidal line indicated by smooth surface, extends to half length of mesoscutum; parascutal carina smooth, glabrous, extends to half length of mesoscutum. Transscutal articulation deep, distinct. Mesoscutellum longer than broad, rectangular, with parallel sides; shorter than mesoscutum, uniformly rugose, overhanging metanotum; scutellar foveae transverse, with smooth, glabrous bottom and strong longitudinal parallel rugae, divided by broad central elevated coriaceous carina. Mesopleuron uniformly rugose, with white setae; speculum reticulate; mesopleural triangle rugose, with dense white setae and some irregular transverse rugae. Metapleural sulcus reaching mesopleuron slightly above half its height, upper part of sulcus indistinct; dorsal axillar area coriaceous, with setae, lateral axillar area smooth, glabrous, with few irregular striae; axillar carina broad, with longitudinal striae; subaxillular bar broad, smooth, glabrous, as high as height of smooth, glabrous metanotal trough. Metascutellum coriaceous, 2.0× as high as height of smooth, glabrous ventral impressed area. Lateral propodeal carinae distinct, broad, subparallel, central propodeal area smooth, glabrous, with central longitudinal and transverse interrupted rugae; lateral propodeal area smooth, with dense white setae; nucha short, with delicate longitudinal sulci dorsally and laterally.

Forewing slightly longer than body, with yellow veins, margin with long cilia; radial cell open, 3.0× as long as broad, R1 and Rs nearly reaching wing margin; areolet triangular, well-delimited by distinct veins; Rs+M projection reaching basalis at mid-height. Tarsal claws without a basal lobe.

Metasoma shorter than head+mesosoma, longer than high in lateral view, second metasomal tergite smooth, glabrous, with dense white setae anterolaterally and without micropunctures; subsequent tergites and hypopygium with dense micropunctures; prominent part of ventral spine of hypopygium as broad as long in ventral view, with white setae ventrally. Body length 3.1–3.7 mm (n = 10).

Gall ( Fig. 30 ). Large abrupt, rounded and multilocular stem swellings encircling woody stems. The gall has a cheese-like texture when young and actively growing, but becomes woody and hard at maturity. The larval cells never emerge through the surface of the gall. The gall is 2 to 4 cm in diameter and height.

Biology. Alternate asexual and sexual generations are known. The asexual generation has been matched with the sexual generation based on DNA sequences, with identical cytb sequences obtained from an asexual female (GenBank accession OK346256 ) and sexual generation male ( OK346255 ). Both generations have been found exclusively on Lake Wales Ridge in Florida, on an endemic oak, Q. inopina . Final instar larvae overwinter in the galls and pupate in March. Asexual females begin to emerge in early April and are fly actively throughout the month, laying eggs that result in integral leaf galls also on Q. inopina . These sexual generation leaf galls grow through the autumn and mature in November. Adults of the sexual generation emerge in December.

Distribution. USA, Florida only, Highlands Co., Lake Wales Ridge endemic; quite common at the Archbold Biological Station, Lake Placid.

Figures

FIGURES 1–10. Andricus archboldi Melika & Abrahamson, sp. nov., sexual generation. 1–4, head, female: 1, frontal view, 2, dorsal view, 3, posterior view, 4, lateral view. 5–8, head, male: 5, frontal view, 6, dorsal view, 7, posterior view, 8, lateral view. 9–10, antenna: 9, female, 10, male.

FIGURES 11–17. Andricus archboldi Melika & Abrahamson, sp. nov., sexual generation, female. 11, mesosoma, lateral view. 12, mesosoma and propleura, frontalview.13, mesoscutum and mesoscutellum, dorsal view. 14, mesoscutum and mesoscutellum, posterodorsal view. 15, metascutellum and propodeum, posterodorsal view. 16, forewing, part. 17, 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.

FIGURES 24–28. Andricus archboldi Melika & Abrahamson, sp. nov., asexual generation, female. 24, mesosoma, lateral view. 25–26, mesosoma, dorsal view. 27, metascutellum and propodeum, posterodorsal view. 28, metasoma, lateral view.

FIGURES 29–30. Andricus archboldi Melika & Abrahamson, sp. nov., galls: 29, sexual, 30, asexual.