1. Changes in the frequency of Cry1Ac resistance genes and shifts in tolerance of cotton bollworm, Helicoverpa armigera , to the Cry1Ac toxin were assessed using bioassays of F 1 and F 2 offspring of isofemale lines from Anci County of Hebei Province (a multiple-crop system including corn, soybean, peanut, and Bt cotton) and Xiajin County of Shandong Province (an intensive Bt cotton planting ar...

Evolution of resistance by insect pests can reduce the benefits of insecticidal proteins from Bacillus thuringiensis (Bt) that are used extensively in sprays and transgenic crops. Despite considerable knowledge of the genes conferring insect resistance to Bt toxins in laboratory-selected strains and in field populations exposed to Bt sprays, understanding of the genetic basis of field-evolved r...

cotton bollworm, helicoverpa armigera (hübner) is one of the most destructive insect pests on many crops in the world that has been found to develop resistance against conventional insecticides. using insecticides with different modes of action may result in appropriate control of the pest and delay insecticide resistance development. in this study, lethal and sublethal effects of emamectin ben...

the cotton bollworm, helicoverpa armigera (hübner), is a serious pest on a wide range of economic crops in many parts of the world. in this study, digestive proteolytic and amylolytic activities of h. armigera larvae (3rd to 5th instars) were evaluated on five main host plants including chickpea (cv hashem), cowpea (cv mashhad), soybean (cv 033), navybean (cv dehghan), and corn (cv sc 704) at 2...

Trichogramma brassicae (Bezdenko) is the most important species of Trichogramma parasitoids in Iran. The cotton bollworm, Helicoverpa armigera (Hubner) is a polyphagous insect pest that attacks many crops including cotton, maize, soybean, tomato, etc. The bollworm egg is a suitable target for many Trichogramma species. Factitious hosts such as eggs of the flour moth, Anagasta kuehniella (Zeller...

www.frontiersinecology.org © The Ecological Society of America T the world, humans compete with a multitude of pest species for food, fiber, and timber, although natural predators greatly reduce the densities of many of these pests. Loss of natural pest control services could have important economic, environmental, and human health consequences (Daily 1997). The Brazilian free-tailed bat (Tadar...

The cotton pest, pink bollworm (Pectinophora gossypiella (Saunders)), is a significant pest in most cotton-growing areas around the world. In southwestern USA and northern Mexico, pink bollworm is the target of the sterile insect technique (SIT), which relies on the mass-release of sterile pink bollworm adults to over-flood the wild population and thereby reduce it over time. Sterile moths rear...

Transgenic cotton that has been engineered to produce insecticidal toxins from Bacillus thuringiensis (Bt) and so to resist the pest cotton bollworm (Helicoverpa armigera) has been widely planted in Asia. Analysis of the population dynamics of H. armigera from 1992 to 2007 in China indicated that a marked decrease in regional outbreaks of this pest in multiple crops was associated with the plan...

the significant reduction of bollworm infestation by the implementation of integrated pest management (ipm) in bt cotton as a component of ipm led to reduction in bollworm infestation and increase in yield. however, these alterations have brought in many new biotic problems hitherto unknown or of little economic importance. field survey of rainfed bt cotton fields in perambalur district of tami...

The sterile insect technique (SIT) is an environmentally friendly method of pest control in which insects are mass-produced, irradiated and released to mate with wild counterparts. SIT has been used to control major pest insects including the pink bollworm (Pectinophora gossypiella Saunders), a global pest of cotton. Transgenic technology has the potential to overcome disadvantages associated w...