Parasitoids, Hyperparasitoids, and Inquilines Associated With the Sexual and Asexual Generations of the Gall Former, Belonocnema treatae (Hymenoptera: Cynipidae)

Abstract

Insect-induced plant galls are thought to provide gall-forming insects protection from predation and parasitism, yet many gall formers experience high levels of mortality inflicted by a species-rich community of insect natural enemies. Many gall-forming cynipid wasp species also display heterogony, wherein sexual (gamic) and asexual (agamic) generations may form galls on different plant tissues or plant species. Despite broad interest in using these systems to study parasitism, enemy escape, and community assembly, few studies have provided complete characterizations of the natural enemy diversity associated with gall-forming wasp species, and fewer still have done so for both alternating generations. Here, we characterize the parasitoids, inquilines, and hyperparasitoids associated with the alternating sexual and asexual generations of the cynipid gall former, Belonocnema treatae Mayr in Texas, USA. We find 24 species associated with the asexual generation in leaf galls and four species associated with the sexual generation in root galls. We provide photographs and mitochondrial sequences for most species, discuss implications of these findings for hypotheses that consider heterogony as an adaptation for escape from natural enemies, and contemplate the relative incidence of specialized versus generalist feeding habits among gall former natural enemies.