Success StoryRearing of endoparasites of corn earworm in laboratory conditions



Rearing of endoparasites of corn earworm in laboratory conditions

Author: Raul Villanueva

Planning Unit: Entomology

Major Program: Hemp

Outcome: Intermediate Outcome

Corn earworm (CEW) is a polyphagous pest that attacks industrial hemp causing damage to the inflorescence. We are monitoring arthropod pests and their natural enemies since the industrial hemp returned to Kentucky agricultural fields. The latter group of insects is of grand significance considering the short list of registered pesticides for hemp. Currently, we have identified two tachinid flies (Winthemia rufopicta and Lespesia aletiae) in collaboration with Dr J. Stireman from Wright University. These two flies parasitized larvae of corn earworm. To rear these parasites, we began to use hemp leaves/inflorescences which increased the workload due to the frequent replacement of food. We tested a lepidopteran diet that we previously used for rearing other moth species. It worked well for CEW parasitized larvae, and we have been able to survey CEW parasitoids, distribution in Kentucky and study the parasitism relationship. In the 2022 Hemp science Conference, we presented our work on CEW parasitism, research teams from two other universities requested the protocols to work in this system and diet to rear CEW and other noctuid moths. A peer-reviewed article titled “Tachinid fly parasitism of outbreaking populations of corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), in cultivated hemp. Tachinid fly parasitism of outbreaking populations of corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), in cultivated hemp” was published (Insects 13(6):519. DOI: 10.3390/insects13060519).