Incorporating a variant of HzNv2 into IPM programs against corn earworm (Helicoverpa zea) in Hawai'i

Corn Earworm (Helicoverpa zea) is a major agricultural pest worldwide with over 100 host plants. In corn crops, one larva can mean the loss of an entire ear of corn as in addition to direct feeding damage, they also facilitate fungal and bacterial infections as they feed. Currently, chemical control and Bt transgenic corn varieties are the most common management practices against H. zea. Novel control methods for this pest are urgently needed as it displays resistance to traditional IPM practices. A variant of the sexually transmitted nudivirus HzNv2 has shown nearly one hundred percent sterility in infected individuals of H. zea when tested separately from other IPM practices in several temperate states in the US. This research aims to determine if this virus can be used with other IPM practices in Hawai'i’s tropical climate. The wild-type virus has been detected in Hawai'i using PCR, which allowed us to import the variant strain into Hawai'i for this research. We reared a lab colony from field-collected individuals and fine-tuned the rearing protocol for our facilities. Field research is being conducted at plots in collaboration with Corteva on Oʻahu; we have three replicate treatment plots that sterile H. zea moths were applied to while three controls received no treatment. Our most up-to-date research results will be shared at the 2024 ESA.