Evaluating the impact of selective insecticides on pest and beneficial insect populations in Mississippi soybean production

Soybean looper (Chrysodeixis includens) and corn earworm (Helicoverpa zea) are major lepidopteran pests of soybean in Mississippi. Although naturally occurring predators contribute to pest suppression, insecticide applications are often required to prevent economic losses. Broad-spectrum insecticides, while effective, can disrupt predator communities and lead to secondary pest outbreaks. Recently developed selective insecticides, including chlorantraniliprole (Vantacor), isocycloseram (Plinazolin), and methoxyfenozide (Intrepid 2F), offer potential for managing pests with reduced impact on beneficial arthropods. However, their compatibility with biological control remains unclear. The objective of this study was to evaluate the impact of selective insecticides on pest and predator populations in soybean. A field experiment was conducted at the R.R. Foil Plant Science Research Center in Starkville, MS. Treatments included Vantacor, Plinazolin, Intrepid 2F, Acephate (broad-spectrum standard), and an untreated control, arranged in a randomized complete block design with four replications. Arthropods were collected from whole plots using 25 sweep net passes per plot at 3, 7, and 14 days after treatment. Collections were used to assess treatment effects on both pest and predator abundance over time. This research will provide insight into the compatibility of selective insecticides with biological control in soybean systems.