Large-Scale Management of Insect Resistance to Transgenic Cotton in Arizona - Can Transgenic Insecticidal Crops be Sustained?

Abstract

A major challenge for agriculture is management of insect resistance to toxins from Bacillus thuringiensis (Bt) produced by transgenic crops. Here we describe how a large-scale program is being developed in Arizona for management of resistance to Bt cotton in the pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), and other insect pests of cotton. Financial support from growers makes this program possible. Collaboration between the Arizona Cotton Research and Protection Council, the University of Arizona, and government agencies has led to development of resistance management guidelines, a remedial action plan, and tools for monitoring compliance with the proposed guidelines. Direct participation in development of resistance management policies is a strong incentive for growers to invest in resistance management research. However, more research, regularly updated regulations, and increased collaboration between stakeholders are urgently needed to maintain efficacy of Bt toxins in transgenic crops.

Long-term regional suppression of pink bollworm byBacillus thuringiensiscotton

“…Control of pink bollworm by Bt cotton has helped to substantially reduce insecticide use in Arizona (12). The long-term regional suppression of pink bollworm reported here may further reduce insecticide use and enhance implementation of the refuge strategy, which is mandated by the U.S. Environmental Protection Agency for delaying evolution of pest resistance to Bt cotton (2)(3)(4)(5)(6)(7)(8).…”

“…Nonetheless, evolution of resistance, which has limited suppression of pests by insecticides, would also eliminate the benefits of Bt cotton (28). In contrast to pink bollworm, which is an ecological specialist with relatively low net reproduction spread among many fields (10,12), pests that are generalists (29)(30)(31), sedentary, or have high reproductive rates ( Fig. 1) are less likely to suffer from long-term suppression caused by Bt.…”

“…Symbols represent average population density for two simulations. Filled circles: F ϭ 8, e ϭ 0.1; open circles: F ϭ 8, e ϭ 0.9; filled triangles: F ϭ 12, e ϭ 0.1; open triangles: F ϭ 12, e ϭ 0.9. than 1,100 pheromone traps were set near cotton fields each year across the 15 regions (12,13). Trapping started after an accumulation of 500 heat units.…”

“…Bt cotton was used on a large scale for the first time in Arizona in 1996. Geographic Information System (GIS) technology was used to measure the proportion of Bt cotton in the regions from 1998 to 2000 (12). The correlation between the proportion of Bt cotton used in the regions between 1998 and 1999 and 1999 and 2000 was very high (r ϭ 0.99 and 0.92, respectively; P Ͻ 0.0001 in each case).…”

Plot Refugi untuk Pengelolaan Resistensi Hama terhadap Tanaman Transgenik Bt

“…Sebagai contoh pada tahun 1997 petani kapas Bt di Arizona, Amerika Serikat menurunkan pemakaian pestisida sebesar 5,4 kali semprot untuk hama kapas pink bollworm. Penghematan ini mencapai $80 per acre (Carriere et al, 2001). Secara umum, penanaman kapas Bt secara global menurunkan pemakaian pestisida sebesar 10-15% (Rousch, 1994).…”