Cynipid galls collected in the Centre of Spain associated
with plants of the tribes Lactuceae and Cardueae
(Asteraceae), particularly flower heads of Centaurea and
related species, included an unknown species of Isocolus
Ashmead which is described in this paper. All the insects
were reared from galls collected in summer, and then
kept indoors and forced to overwinter two months in
a fridge at 5 °C.