Spatial and temporal population dynamics of corn earworm in hemp fields in the Delmarva region

Corn earworm (CEW), Helicoverpa zea (Boddie), is a well-known polyphagous and most costly crop pest in temperate and tropical regions. Due to its polyphagous nature, CEW migrates from other crops and becomes a key pest to newly reintroduced hemp, Cannabis sativa L. two field studies were conducted at two separate locations in the Delmarva region Farm (Stewart Neck and Sudlersville, Maryland) during the growing seasons of 2020, 2021, and 2022 to assess the temporal and spatial population dynamics of CEWs on hemp at different locations and in a number of hemp varieties. The number of CEW adults and larvae and the damage inflicted by them were recorded weekly in both locations. There were higher levels of insect infestation in Stewart Neck than in Sudlersville. However, the damage inflicted on the plants was more significant at Sudlerville's location than at Stewart Neck's. Mountain Mango experienced significantly less damage than any of the other hemp varieties. Spraying hemp with an authorized pesticide for CEW beginning in early to mid-August may help prevent damage caused by the large larvae population documented in September and early October of 2020, 2021, and 2022 in the Delmarva region.