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.

Predation of Stink Bugs (Hemiptera: Pentatomidae) by a Complex of Predators in Cotton and Adjoining Soybean Habitats in Georgia, USA

“…For example, application of spinosad did not affect G. punctipes and H. convergens densities in cotton (Tillman & Mulrooney 2000). However, selective insecticides are not always effective against stink bug pests (Tillman et al 2009b). Other tactics are needed for conserving these predators in both conventional and organic cropping systems.…”

Intraguild predation of Orius niger (Hemiptera: Anthocoridae) on Trichogramma evanescens (Hymenoptera: Trichogrammatidae)

“…Like other generalist predators, species of Orius may occur at the same time as species of Trichogramma in agroecosystems and often share one or more species of prey/ host in common (Kayapınar, 1991;Romeis & Shanower, 1996;Tillman et al, 2009;Zappala et al, 2013). Results of this study reveal the occurrence of intraguild predation by O. niger on eggs of E. kuehniella, which were previously parasitized by T. evanescens.…”

Impact of the invasion of the imported fire ant

“…() noted, there are many ant species that prey on plant damaging pest insects, generally the immature stages that are either exposed or accessible such as foliage, flower or fruit feeders. For example, fire ants can be beneficial in controlling certain plant pests (Long et al ., ; Krispyn & Todd, ; Way et al ., ; Seagraves et al ., ; Seagraves & McPherson, ; Tillman et al ., ) but the IFA also can impact both beneficial arthropod ground predators and beneficial species that spend some time in the ground as well as pest species (Seagraves et al ., ; Tillman et al ., ). It is important to note that S. invicta has been reported as a key predator of a number of agricultural pests (Oliver et al ., ).…”

“…In cotton, Tillman et al . () noted that the IFA was among the major predators of two major cotton pests ( Heliothis virescens and Stink bugs). Negm and Hensely () and Reagan et al .…”