Helicoverpa armigera (HuÈbner) and H. zea (Boddie) (Lepidoptera: Noctuidae) in corn, soybean and sunflower in Puerto Rico and the toxicity of selected insecticides to populations of Helicoverpa spp.

Helicoverpa armigera (HuÈbner) and H. zea (Boddie) (Lepidoptera: Noctuidae) in corn, soybean and sunflower in Puerto Rico and the toxicity of selected insecticides to populations of Helicoverpa spp.

Flores-Rivera, X.L.; Paula-Moraes, S.V.; Johnson, J.W.

The old-world bollworm Helicoverpa armigera and corn earworm H. zea (Lepidoptera:Noctuidae) are polyphagous species and considered destructive agricultural pests around the world. In 2014, the occurrence of H. armigera was reported in Puerto Rico. In this study, the occurrence of H. armigera and H. zea in seed production fields of corn, soybean, and sunflower in the southern municipalities of Salinas and Juana Díaz were documented. From 2018 to 2021, a year-round pheromone trapping was conducted, and combined with larval sampling during the three crop seasons. The proportion of H. armigera/H. zea was assessed based on genital morphology and molecular analysis. The susceptibility of H. zea populations to the insecticides spinetoram, emamectin benzoate, chlorantraniliprole, and esfenvalerate were also assessed. Field-derived populations from Salinas and Juana Díaz were established in a seed production system laboratory in Salinas. Laboratory bioassays were performed using a diet-overlay and diet integrated bioassay on third-instar larvae. Mortality was accessed at 24 h, 48 h, 96 h, and for chlorantraniliprole up to 120 h after exposure to the highest dose recommended by label. We discuss the implication on an IPM program to manage Helicoverpa species in seed production in the South of Puerto Rico, and relevance of the results to continental U.S.