Managing Practical Resistance of Lepidopteran Pests to Bt Cotton in China

Abstract

China is one of the major cotton producers globally with small farmers. Lepidopteran pests have always been the main factor affecting cotton production. To reduce the occurrence of and damage caused by lepidopteran pests, China has employed a pest control method focused on planting Bt (Cry1Ac) cotton since 1997. Chinese resistance management tactics for the main target pests, the cotton bollworm and pink bollworm, were also implemented. For polyphagous (multiple hosts) and migratory pests such as the cotton bollworm (Helicoverpa armigera), the “natural refuge” strategy, consisting of non-Bt crops such as corn, soybean, vegetables, peanuts, and other host crops, was adopted in the Yellow River Region (YRR) and Northwest Region (NR). For a single host and weak migration ability pest, such as the pink bollworm (Pectinophora gossypiella), the seed mix refuge strategy yields a random mixture within fields of 25% non-Bt cotton by sowing second-generation (F2) seeds. According to field monitoring results for more than 20 years in China, practical resistance (Bt cotton failure) of target pests was avoided, and there were no cases of Bt (Cry1Ac) failure of pest control in cotton production. This indicated that this Chinese resistance management strategy was very successful. The Chinese government has decided to commercialize Bt corn, which will inevitably reduce the role of natural refuges; therefore, this paper also discusses adjustments and future directions of cotton pest resistance management strategies.

Moderate nitrogen application facilitates Bt cotton growth and suppresses population expansion of aphids (Aphis gossypii) by altering plant physiological characteristics

“…In contrast, the Bt protein content of cotton peaked at 0.9g/kg nitrogen fertilizer level, but subsequently dropped obviously with the elevation of nitrogen fertilizer levels ( Figures 2A-C ). It is well known that transgenic Bt cotton can effectively inhibit various target pests ( Kranthi and Stone, 2020 ; Quan and Wu, 2023 ). Therefore, for the target pests of N15-5 transgenic insect-resistant cotton, we believe that the control effect of medium nitrogen fertilizer level (0.9 g/kg) will be better and with the increase of nitrogen fertilizer dosage, the decrease of Bt protein may inevitably lead to the rampant of Bt cotton target pests.…”

Potential inhibitory effects of compounds ZK-PI-5 and ZK-PI-9 on trehalose and chitin metabolism in Spodoptera frugiperda (J. E. Smith)

“…Nature published an article entitled “Invasive alien pests hit Africa hard, ” which was about the large-scale invasion of S. frugiperda, causing global concern ( Wild, 2017 ). Various measures have been taken to prevent and control the noctuid moth on the grassland, such as Bt maize ( Quan and Wu, 2023 ). But so far, there is no means to comprehensively and effectively improve the overall control effects of S. frugiperda , due to its fast reproduction, wide harm, and strong migration ability, coupled with the lack of natural enemies, insufficient control experience, and poor control effects ( Brévault et al, 2018 ; Kenis et al, 2022 ; Luo et al, 2022 ).…”

Molecular screening of local Indonesian rice to identified resistant varieties against brown planthopper (Nilaparvata lugens) attacks

“…Control is often carried out using chemicals, which in the long term will cause pest resistance (Quan and Wu 2023). Proper control does not cause pest resistance and is environmentally friendly, using resistant varieties (Niones et al 2022).…”