Bioscience Methods 2024, Vol.15, No.4, 196-206 http://bioscipublisher.com/index.php/bm 1 99 pests away from the main crop. For instance, planting trap crops around cotton fields can lure pests like bollworms away from the cotton, reducing the need for chemical controls (Veres et al., 2020; Rowen et al., 2022). 3.4 Chemical Control in IPM 3.4.1 Selective use of pesticides While IPM emphasizes non-chemical methods, the selective use of pesticides is sometimes necessary. The key is to use pesticides judiciously and only when pest populations exceed economic thresholds. Selective pesticides that target specific pests while sparing beneficial organisms are preferred. This approach helps in maintaining the ecological balance and reducing the risk of pest resistance (Wilson et al., 2018; Green et al., 2020; Deguine et al., 2021). 3.4.2 Resistance management strategies Resistance management is a critical component of IPM, aimed at delaying the development of pest resistance to pesticides. Strategies include rotating pesticides with different modes of action, using pesticide mixtures, and integrating non-chemical control methods. These practices help in sustaining the effectiveness of pesticides and ensuring long-term pest control (Wilson et al., 2018; Green et al., 2020; Deguine et al., 2021). By integrating these diverse strategies, IPM provides a sustainable approach to managing pests in cotton crops, promoting environmental health and agricultural productivity. 4 Biotechnological Advances in Cotton Pest Management 4.1 Genetic engineering and Bt cotton 4.1.1 Development and adoption of Bt cotton Bt cotton, genetically engineered to express insecticidal proteins from the bacterium Bacillus thuringiensis (Bt), has revolutionized pest management in cotton crops. The introduction of Bt cotton has significantly reduced the reliance on chemical insecticides, leading to a decrease in environmental impact and production costs. The adoption of Bt cotton has been widespread due to its effectiveness in controlling major pests such as the cotton bollworm (Helicoverpa armigera) and the pink bollworm (Pectinophora gossypiella) (Figure 2) (Razzaq et al., 2023; Bally et al., 2020). Razzaq et al. (2023) illustrates the impact of Bt cotton on pest-community interactions within the agricultural ecosystem. Bt cotton, engineered to produce Cry toxins, targets specific pests like the cotton bollworm (H. armigera). The Cry toxins disrupt the lifecycle of these pests, effectively reducing their populations. The diagram shows how Bt cotton serves as a "death trap" for cotton bollworms, not only controlling their numbers but also indirectly protecting other crops such as corn, peanut, and soybean by breaking the pest's host chain. Additionally, the figure highlights the influence of Bt toxins on the rhizosphere and phyllosphere, affecting soil microbiomes and enzyme activities. The decline in cotton bollworm populations with increased Bt cotton cultivation underscores the effectiveness of this biotechnological approach. 4.1.2 Impact on pest populations and resistance While Bt cotton has been successful in reducing pest populations and increasing crop yields, the evolution of resistance in target pests poses a significant challenge. Instances of resistance have been documented, leading to increased feeding injury and reduced effectiveness of Bt crops (Gassmann and Reisig, 2022). Strategies such as the refuge strategy, which involves planting non-Bt cotton alongside Bt cotton, and the pyramiding of multiple Bt genes, have been implemented to delay resistance development (Ma and Zhang, T., 2018; Razzaq et al., 2023). Additionally, integrating Bt with RNA interference (RNAi) technology has shown promise in managing resistance by providing a new mode of action (Ma and Zhang, T., 2018; Kang et al., 2021). 4.2 RNA interference (RNAi) technology 4.2.1 Mechanisms and applications RNA interference (RNAi) is a biological process where double-stranded RNA (dsRNA) induces the degradation of specific messenger RNA (mRNA) molecules, effectively silencing target genes. This technology offers high
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