Importance of WBC management to reduce the risk of disease and mycotoxin in corn

Western bean cutworm, Striacosta albicosta, is native to North America. In Canada, it is an important insect pest of corn, Zea mays. Larvae can dig holes and galleries in the corn ears. Larval feeding by S. albicosta can directly reduce yield. The occurrence of frass in corn ears can also affect the grain quality. Western bean cutworm larvae can facilitate secondary infection of corn by fungal pathogens (e.g. development of Fusarium graminearum Schwabe (Nectriaceae), the causal agent of Gibberella ear rot). This pathogenic fungus can produce different mycotoxins, which are toxic and harmful for livestock. Insecticides, transgenic corn hybrids, and cultural control tactics have been investigated to manage S. albicosta. Biological control is also of interest and various entomopathogens and generalist predators have been investigated. Several species of trichogramma egg parasitoids have also been reared from S. albicosta eggs. Surveys were conducted in the province of Quebec for Trichogramma spp. in corn fields. The efficacy of Trichogramma minutum, a potential biological control agent of S. albicosta is also evaluated to apply them by drone in corn fields to help to reduce the risk of Gibberella ear rot development.