Seasonal Abundance of the Adventive Chinese Tallowtree Herbivore Caloptilia triadicae (Lepidoptera: Gracillariidae) and Its Parasitoids

Chinese tallowtree, Triadica sebifera (L.) Small (Malpighiales: Euphorbiaceae), is an invasive weed from southern China that is invasive in the Gulf states of the southeastern USA. One significant factor that contributes to the success of this weed has been the lack of herbivore species attacking it in the invaded range. However, the leafminer species Caloptilia triadicae Davis (Lepidoptera: Gracillariidae) was discovered feeding on Chinese tallowtree in Florida in 2008 and has now been found throughout much of the plant's invaded range. We monitored the seasonal abundance of C. triadicae populations and their associated parasitoids over 2 yr in Florida. Populations of C. triadicae peaked in Jun and Jul in 2013 and 2014. Parasitism averaged about 3.3% of larvae and pupae, with a peak of 12%. The most abundant parasitoid species was Goniozus sp. (Hymenoptera: Bethylidae) (76% of all parasitoid individuals reared) and, second, Brasema sp. (Hymenoptera: Eupelmidae) (18% of parasitoids). Due to specific niche requirements and the apparent exploitation of leaf mines by these parasitoid species, it is doubtful they will attack species being considered for biological control of Chinese tallowtree.