Acraspis villosa Gillette, 1888, sexual generation

[Synonyms listed are for the agamic generation; see that page for details]

Gall (Fig. 28). The sexual galls are not apparently distinguishable from galls of the sexual generation of Acraspis quercushirta, described above. [Sexual galls develop in the innermost scales in apical and lateral buds, a brittle, thin-walled, seed-like, sub-ovoid cell approximately 2 mm long, tan or orange-brown when mature, with faint longitudinal striations and sparse, pale hairs. Galls form in the basal portion of the scale and often leave the scale apex intact, which extends as a flat flap beyond the gall.]

Biology. See Weld (1926) and Kinsey (1930, 1936) for the biology of the asexual generation. Asexual galls (Fig. 27) from species in Kinsey’s (1936) “villosa” complex have been recorded on leaves of Q. alba, Q. arizonica, Q. gambelii, Q. grisea, Q. macrocarpa and Q. oblongifolia. Adult females of the asexual generation emerged (from galls collected in Manitoba but reared in Edmonton) during the second half of October and early November. Adults of the sexual generation emerged in Edmonton from late May to early June. Galls of the asexual generation appeared on leaves in Edmonton in July.

Distribution. USA: New York, Michigan, Iowa, Kansas, Texas, Utah, Arizona (Burks 1979); Canada: Manitoba

- James Nicholls, George Melika, Scott Digweed, Graham Stone: (2022) Pairing of sexual and asexual generations of Nearctic oak gallwasps, with new synonyms and new species names (Hymenoptera: Cynipidae, Cynipini)^©