Abstract
Through experimental rearing, heterogony (the alternation of unisexual and bisexual
generations) was demonstrated in the cynipid species Belonocnema treatae Mayr 1881.
Female B. treatae (bisexual generation) induce galls on the leaves of Ouercus fusiformis
Small (Fagaceae), from which unisexual females, previously described as B. kinseyi Weld
1921, emerge. Unisexual females induce galls on the roots of~ fusiformis. The name B.
treatae has priority, so B. kinseyi becomes a new synonym. Adults of each generation and
the galls they induce are described. Timing events in the life cycle of B. treatae on its host
plant are described for populations in central Texas. Hymenopteran inquilines and
parasitoids of B. treatae are identified, and aspects of the impact of natural enemies on B.
treatae success are described.