Helicoverpa armigera (Hubner) and Helicovera zea (Boddie) (Lepidoptera: Noctuidae) in Puerto Rico: phenology of flight, analysis of hybrid presence, and insecticide performance in field crops

Abstract

The genus Helicoverpa (Hardwick) includes several species of agricultural pests around the world. The polyphagous pest Helicoverpa armigera reported in several countries in South America in 2013, was reported in Puerto Rico in 2014. However, information about the impact of this invasive species on field crops is still needed. The objective of this study was to document the occurrence of H. armigera and H. zea in corn, soybean, and sunflower in the southern municipalities of Puerto Rico. Year-round pheromone trapping of adult males combined with larval sampling was conducted from 2018-2021. The abundance of moths detected in the trapping indicated an increase in the population from October to March, and Juana Diaz had a high occurrence of Helicoverpa spp. than Salinas. The proportion of H. armigera/H. zea and detection of congeneric hybrids were assessed based on genital morphology and DNA analysis. Neither H. armigera nor expected hybrids between H. zea and H. armigera were detected in the present study. The susceptibility of H. zea populations to the insecticides Spinetoram, Emamectin benzoate, Chlorantraniliprole, and Esfenvalerate was assessed, and an overall significant effect of insecticide susceptibility was detected. Chlorantraniliprole and Emamectin benzoate had the highest performance. These results of this study, performed in one of the largest winter nursery breeding operations in the United States, contribute to the IPM/IPM programs to Helicoverpa spp. located in the southern municipalities of Puerto Rico. In addition, and validate information to be considered in mitigation plans, in the scenario of an invasion of H. armigera in the continental U.S.

Lepidoptera research in Puerto Rico: Reconnecting with historical legacies to guide future priorities

“…Studies on Helicoverpa spp. in Puerto Rico have evaluated insecticide resistance, flight phenology, hybridization, morphology, and efficacy of pheromone trapping(da Silva et al, 2020, Flores-Rivera et al, 2022 …”