Aulacidea subterminalis Niblett, 1946

Feeds on: Induces galls on Hieracium L. spp. [H canadense added as a placeholder]

Distribution: United States (Possibly introduced); Canada: British Columbia (Introduced)

Similarly, the subterminal hawkweed gall wasp (Aulacidea subterminalis) may also have been introduced to North America. Its galls apparently occur on the stolons rather than on the main stem. However, like the Canada hawkweed stem gall wasp, its status in North America is unclear.

Gall (Plate 8.9). Galls develop under the leaf rosette, at the main base of the midrib, more rarely on the main vein of the leaf. Inducing very inconspicuous galls, the leaf externally is not malformed.
Biology. Monovoltine. Larvae overwintering in the gall, adults emerge next spring, in July– August (Zerova, Diakontschuk & Ermolenko, 1988). Host plants: Hieracium pilosellae L., H. cymosum L. (Kierych, 1979), H. pratense L.

GALL
Hard, hairy, multilocular swelling, as large as a marble, in a stolon, just below a rosette.