Pest Insects and Natural Enemies in Transitional Organic Cotton in Georgia

Abstract

This research was conducted in experimental plots in Georgia from 2004 through 2006 and assessed the prospects for transitioning to a totally organic management system for cotton. The seasonal abundance of insect pests and their natural enemies over the 3-yr transitional period are reported herein. The heliothines, Heliothis virescens (F.) and Helicoverpa zea (Boddie), and stink bugs, mainly Nezara viridula (L.), Euschistus servus (Say), and Euschistus quadrator (Rolston), were the 2 groups of insect pests found on cotton. Heliothine larvae were observed each year of the study but, in general, infestations of heliothines were higher in 2004 than in the other 2 yrs. Stink bugs were observed in relatively high numbers, and the percent of cotton bolls damaged by these pests was high only during year 2 of the study. Over the 3-yr period, the red imported fire ant, Solenopsis invicta Buren, various spiders, including Oxyopes scalaris Hentz and Peucetia viridans (Hentz), the big-eyed bug, Geocoris punctipes (Say), and the pirate bug, Orius insidiosus (Say), were the most abundant predators of the heliothines and stink bugs. The endoparasitoid Toxoneuron nigriceps Viereck and an ascovirus also contributed to larval mortality of H. virescens. The endoparasitoid Trichopoda pennipes (F.) parasitized adults of N. viridula.