In some previously reported cases, transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) have suppressed insect pests not only in fields planted with such crops, but also regionally on host plants that do not produce Bt toxins. Here we used 16 years of field data to determine if Bt cotton caused this "halo effect" against pink bollworm (Pectinophora gossypiella) in s...

1) Moth Trapping. Despite the use of Bt-transgenic cotton on over 98% of the acreage in Tennessee, bollworm and tobacco budworm still compose an important pest complex. Bollworms may cause significant economic damage to Bt cotton fields, and the bollworm/budworm can be even more damaging to non-Bt cotton. More importantly, the threat of tobacco budworm infestations results in high adoption of B...

Background: Cotton with coevolving pests has been grown in India more than 5000 years. Hybrid cotton was introduced in the 1970s with increases in fertilizer and in insecticide use against pink bollworm that caused outbreaks of bollworm. Hybrid Bt cotton, introduced in 2002 to control bollworm and other lepidopteran pests, is grown on more than 90 % of the cotton area. Despite initial declines,...

Genetically modified cotton, Gossypium hirsutum L., cultivars ('Bollgard') that produce crystalline proteins from Bacillus thuringiensis (Berliner) are valuable tools for managing lepidopteran insect pests in the United States. However, high numbers of bollworm, Helicoverpa zea (Boddie), larvae have been observed feeding in white flowers of these cultivars. Fresh tissue bioassays were conducted...

Regional suppression of pests by transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) has been reported in several cropping systems, but little is known about the functional relationship between the ultimate pest population density and the pervasiveness of Bt crops. Here we address this issue by analyzing 16 years of field data on pink bollworm (Pectinophora gossypi...

Field studies were performed during 2005 and 2006 to determine bollworm, Helicoverpa zea (Boddie), and tobacco budworm, Heliothis virescens (F.), larval behavior on conventional non-transgenic cotton plants (Coker 312), and on transgenic Bacillus thuringiensis Berliner (Bt) plants expressing the Vip3A protein or a combination of Vip3A + Cry 1Ab proteins (VipCot). Plants representing each of the...

Cotton bollworm, Helicoverpa armigera, is a major insect pest that feeds on cotton bolls causing extensive damage leading to crop and productivity loss. In spite of such a major impact, cotton plant response to bollworm infection is yet to be witnessed. In this context, we have studied the genome-wide response of cotton bolls infested with bollworm using transcriptomic and proteomic approaches....

Climate change has changed numerous species phenologies. Understanding the asynchronous responses between pest insects and host plants to climate change is helpful in improving integrated pest management. It is necessary to use long-term data to analyze the effects of climate change on cotton bollworm and wheat anthesis. Data for cotton bollworm, wheat yield, and wheat anthesis collected since ...

China is the largest cotton-producer in the World with about 4.5 million tons of lint produced annually, which accounts for over 20% of the World’s total production (Xia et al. 2001). Damage from pests is one of the major limiting factors for cotton production in China, among which cotton bollworm (Helicoverpa armigera Hübner) is a key one (Fang et al. 1992). In the early 1990s, due to the dram...

Transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) kill some key insect pests, but evolution of resistance by pests can reduce their efficacy. The main approach for delaying pest adaptation to Bt crops uses non-Bt host plants as "refuges" to increase survival of susceptible pests. To delay evolution of pest resistance to transgenic cotton producing Bt toxin Cry1Ac...