Andricus columbiensis Melika, Nicholls & Stone, 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 : 28-32

Andricus columbiensis Melika, Nicholls & Stone , sp. nov.

Figs. 89–100

urn:lsid:zoobank.org:act:9CDC5EDE-1970-4B6A-A15D-035FF6FAD379

Type material: HOLOTYPE female “ Canada, British Columbia, Burgoyne Bay Provincial Park, leg. J. Nicholls, 2007.11.12. Code BC208, spBCb3; ex Quercus garryana ” . PARATYPES: 11 females; 5 females with the same labels as the holotype, only with different codes ( BC212 , spBCb3_2— 1 female; BC208, spBCb3_4— 1 female; BC212, spBCb3_6— 1 female; BC205, spBCb3_1— 2 females) and 5 females labeled as “ Canada, Nose Point, Salt Spring Island, leg. J.A. Nicholls. 2007.11.10. ex Quercus garryana ”. Codes BC 197 (1 female), BC198 (1 female), BC199 (3 females) and BC200 (1 female). The holotype and three females are deposited at the USNM , 8 females at the PHDNRL .

Etymology. Named after the Canadian province of British Columbia, where this species was first found.

Diagnosis. The galls of A. columbiensis on Q. garryana resemble those of A. occultatus ( Weld, 1926) , previously known from California, which induces galls on Q. douglasii , Q. dumosa , Q. lobata . However, in A. occultatus the female antenna has 11 flagellomeres, the mesoscutum with sparse setae, the prominent part of the ventral spine of hypopygium about 3.0× as long as broad in ventral view, while in A. columbiensis the antenna has 12 flagellomeres, the mesoscutum with uniformly dense white setae, the prominent part of the ventral spine of hypopygium 6.0× as long as broad in ventral view. Asexual A. opertus ( Weld, 1926) , also known from California, induces similar cryptic bud galls on Q. douglasii and Q. lobata . However, in A. opertus the female antenna has 11 flagellomeres, the pronotum laterally with setigerous punctures, the mesopleuron without longitudinal rugae, the prominent part of the ventral spine of hypopygium about 10.0× as long as broad in ventral view, while in A. columbiensis the antenna has 12 flagellomeres, the pronotum laterally with numerous parallel striae, the mesopleuron has parallel transverse striae at mid height, the prominent part of the ventral spine of hypopygium 6.0× as long as broad in ventral view. Another Andricus species , A. schickae has an asexual generation that also induces cryptic bud galls. However, in A. columbiensis the inner margins of eyes parallel, OOL 1.3× as long as diameter of lateral ocellus, the transfacial distance as long as height of eye, the clypeus quadrangular, nearly as high as broad, the mesoscutum coriaceous, the median mesoscutal line extends to 1/3 of the mesoscutum length, the radial cell of the forewing 3.5× as long as broad, the hypopygium without micropunctures, the prominent part of the ventral spine of the hypopygium 6.0× as long as broad in ventral view, with a few setae ventrally which do not extend beyond apex of spine; in contrast, in A. schickae asexual females the inner margins of eyes converge ventrally, OOL 2.0× as long as diameter of lateral ocellus, the transfacial distance longer than height of eye, the clypeus small, trapezoid, slightly broader than high, the mesoscutum uniformly alutaceous, the median mesoscutal line in the form of a short triangle; the radial cell of the forewing 4.5× as long as broad, the hypopygium with micropunctures, the prominent part of the ventral spine of the hypopygium more than 10.0× as long as broad in ventral view, without setae.

Description. Asexual female ( Figs. 89–99 ). Head, antennae and mesosoma dark brown to black; mandibles, maxillary and labial palpi brown; tegulae light brown; legs light brown to yellowish; metasoma reddish brown, dorsally always darker.

Head delicately coriaceous, with dense white setae on lower face, vertex, occiput and postgena; 1.2× as broad as high and slightly broader than mesosoma in frontal view, 2.2× as broad as long from dorsal view. Gena alutaceous, strongly broadened behind eye, broader than transverse diameter of eye. Malar space alutaceous, glabrous, with striae radiating from clypeus and reaching eye; eye 2.6× as high as length of malar space. Inner margins of eyes parallel. POL 2.45× as long as OOL; OOL 1.3× as long as diameter of lateral ocellus and 0.8× as long as LOL; all ocelli ovate, of same size. Transfacial distance as long as height of eye; diameter of antennal torulus 1.9× as long as distance between them, distance between torulus and eye as long as diameter of torulus; lower face coriaceous, glabrous, without striae, with dense long white setae; slightly elevated median area alutaceous, glabrous, with few setae. Clypeus quadrangular, nearly as high as broad, smooth, glabrous, with setae, ventrally rounded, not emarginate, without median incision; anterior tentorial pit small, rounded, indistinct, epistomal sulcus distinct, deep, clypeo-pleurostomal line well impressed. Frons alutaceous, with few setae, without striae; interocellar area coriaceous. Vertex and postgena alutaceous, with dense white setae, occiput and postocciput smooth, glabrous, without setae; posterior tentorial pit small, rounded, area below impressed; occipital foramen shorter than height of postgenal bridge; hypostomal carina emarginate, continuing into postgenal sulci which diverge anteriorly, postgenal bridge anteriorly as broad as occipital foramen. Antenna longer than head+mesosoma, with 12 flagellomeres and long dense white setae; pedicel slightly longer than broad; flagellomeres slightly broadened towards apex, F1 2.0× as long as pedicel and equal in length to F2; F2 1.3× as long as F3; F3=F4, F5–F11 nearly equal in length, F12 1.6× as long as F11, placodeal sensilla on F3–F12.

Mesosoma 1.2× as long as high, with dense white setae, except mesopleuron and central propodeal area. Pronotum glabrous, with dense setae, laterally with numerous parallel striae; propleuron uniformly smooth, glabrous. Mesoscutum coriaceous, with uniformly dense white setae, slightly longer than broad (greatest width measured across mesoscutum at level of base of tegulae). Notaulus complete, with smooth, glabrous bottom, posteriorly broader and converging; anterior parallel line smooth, glabrous, extends to half length of mesoscutum; parapsidal line distinct, smooth; median mesoscutal line smooth, glabrous, extends to 1/3 of mesoscutum length; circumscutellar carina broad, reaching notaulus. Mesoscutellum trapezoid, slightly longer than broad, broader in posterior half, rugose, with net of strong irregular rugae; posteriorly rounded, overhanging metanotum. Mesoscutellar foveae separated by elevated coriaceous central carina, transverse, with smooth, glabrous bottom. Mesopleuron and speculum uniformly smooth, glabrous, with parallel transverse striae at mid height, ventrally and posteriorly with dense setae; mesopleural triangle coriaceous, with net of delicate rugae, with white setae; dorsal and lateral axillar areas delicately coriaceous, with dense white setae; subaxillular bar smooth, glabrous, with parallel sides, as high as height of metanotal trough; metapleural sulcus reaching mesopleuron in mid height, upper part of sulcus distinct, delimited area broad. Metascutellum coriaceous, 3.0× as broad as smooth, glabrous ventral impressed area; metanotal trough smooth, glabrous, with dense setae; central propodeal area smooth, glabrous, without rugae; lateral propodeal carinae bent strongly outwards in posterior 1/3; lateral propodeal area smooth, glabrous, with long dense white setae. Nucha with numerous delicate sulci dorsally and laterally. Tarsal claws with basal lobe.

Forewing longer than body, hyaline, margin with dense cilia, veins light brown, radial cell open, 3.5× as long as broad; R1and Rs reaching wing margin; areolet triangular, closed, distinct. Rs+M inconspicuous, its projection reaching basalis at mid height.

Metasoma as long as mesosoma, higher than long in lateral view; second metasomal tergite extending to 4/5 of metasoma length in dorsal view, with dense numerous white setae anterolaterally, without micropunctures; subsequent tergites glabrous, with micropunctures laterally. Hypopygium without micropunctures, prominent part of ventral spine of hypopygium 6.0× as long as broad in ventral view, with a few setae ventrally which do not extend beyond apex of spine. Body length 2.5–2.9 mm (n = 10).

Gall ( Fig. 100 ). A cryptic bud gall, located within a slightly swollen terminal or lateral bud; gall contains a single larval chamber (occasionally two) at base of bud within the meristematic tissue, below the point at which the bud scales are attached.

Biology. Only an asexual generation is known, which induces cryptic bud galls on Q. garryana . Adults emerge in late autumn. Specimens from two locations were sequenced for cytb and ITS2, with two cytb haplotypes observed differing by 0.92% ( OK 346264 – OK346267 ) and two ITS2 sequences found that differed only by a single base insertion ( OK 350630 – OK350637 ) .

Distribution. Canada, British Columbia, southern Vancouver Island and adjacent Gulf Islands.

Figures

FIGURE 100. Andricus columbiensis Melika, Nicholls & Stone, sp. nov., asexual generation, galls.

FIGURES 89–94. Andricus columbiensis Melika, Nicholls & Stone, sp. nov., asexual generation, female: 89–92, head: 89, frontal view, 90, posterior view, 91, dorsal view. 92, lateral view. 93, antenna. 94, forewing, part.

FIGURES 95–99. Andricus columbiensis Melika, Nicholls & Stone, sp. nov., asexual generation, female: 95, mesosoma, lateral view, 96–97, mesosoma, dorsal view, 98, metascutellum and propodeum, posterodorsal view, 99, metasoma, lateral view.