author(s)
Showket A Dar, Amir B Wani and Ajaz A Kandoo

abstract
In agriculture the Bacillus thuringensis as insecticidal toxins have been used for insect pest management for decades. The specific molecular interaction between the toxin and the insect midgut receptors makes the Bt a popular choice for pest control. This specificity of the action of Bt toxins reduce the concern of adverse effect on the non-target species, a concern which remains with the chemical insecticides since centuries. Different class of toxins are produced by Bt and to maximise the effect the diferent toxins are often combined which makes the Bt expression in then transgenic more effective. Although, the Bt is very effective, but there are concerns over the resistance development by insects species and also the narrow spectrum of activities of individual toxins. Gene flow, cross- resistance and hazards to the environment are of major concern in developed countries. Research is in progress to improve the toxicity of the Bt-toxins so as to control the resiatnce development. Therefore the aim of present revive is to explain the genetic engineering of the plants for insect control, disadvantages and strategies for the continuous research, development and improvement of Bt and non-Bt resistance products to tackle the insect pests problems without any harmful impact on the environment.