Benefits of Bt cotton counterbalanced by secondary pests? Perceptions of ecological change in China

  title={Benefits of Bt cotton counterbalanced by secondary pests? Perceptions of ecological change in China},
  author={Jennifer H Zhao and P. P. S. Ho and Hossein Azadi},
  journal={Environmental Monitoring and Assessment},
In the past, scientific research has predicted a decrease in the effectiveness of Bt cotton due to the rise of secondary and other sucking pests. It is suspected that once the primary pest is brought under control, secondary pests have a chance to emerge due to the lower pesticide applications in Bt cotton cultivars. Studies on this phenomenon are scarce. This article furnishes empirical evidence that farmers in China perceive a substantial increase in secondary pests after the introduction of… 
Managing pests after 15 years of Bt cotton: Farmers' practices, performance and opinions in northern China
The results indicated that farmers used chemicals somewhat intensively, carrying out 11 insecticide sprayings on average, involving an average of 2 pest target-oriented insecticide controls, and the pest complex shift phenomenon was confirmed as farmers aimed 60% of target- oriented insecticide control at sucking pests, principally aphids even more than Lygus bugs.
Trend analysis of pests and diseases complex in Bt cotton
If left unchecked these pests and disease problems are capable of undoing all benefits gained due to Bt cotton in terms of increased yield and reduction in use of chemical pesticides.
Ecological and physiological features of Bt-plants causing outbreaks of secondary pests
  • A. Viktorov
  • Biology
    Russian Journal of Plant Physiology
  • 2017
In the area occupied with Bt-crops caused by their cost inefficiency, a highly important place belongs to the representatives of the order Hemiptera, which are insensitive to Cry-proteins of genetically modified insecticidal crops engineered to control the main pests from the orders Lepidoptera and Coleoptera with chewing mouthparts.
The impact of secondary pests on Bacillus thuringiensis (Bt) crops.
The main causes surrounding secondary pest dynamics in Bt crops and the impact of such outbreaks are reviewed and recommendations for future research are outlined that will help to improve the knowledge of the possible long-term ecological trophic interactions of employing this technology.
Comparative incidence of cotton spider mites on transgenic Bt versus conventional cotton in relation to contents of secondary metabolites
Reductions in gossypol and tannin contents in Bt cotton decreased the generation time and increased the number of eggs of cotton spider mites, and the fitness of the mites on Btotton was higher than on non-Bt cotton.
Evaluation of the Impact of Genetically Modified Cotton After 20 Years of Cultivation in Mexico
It is still necessary to implement national research programs, so that biotechnology and plant breeding advances can be used in the development of cotton varieties adapted to the Mexican particular environmental conditions and to control insect pests of regional importance.
Diversity of Phytophagous Insects with Potential to Become Key Pests in Genetically Modified Bt Cotton
Abstract. Reduction in pests targeted by Bt cotton is widely studied; however, other phytophages not affected by Bt cotton-expressed toxins are increasing, suggesting these potential pests might
Deconstructing Indian cotton: weather, yields, and suicides
Bt cotton may be economic in irrigated cotton, whereas costs of Bt seed and insecticide increase the risk of farmer bankruptcy in low-yield rainfed cotton.
Is Bt Gene Cotton Adoption Paying Off Farmers in Pakistan?
Existing literature on impact of Bacillus Thuringiensis (Bt) cotton gene adoption in Pakistan is based on districts of one province and one or two years of data. This study contributes to literature
Bt cotton seed purity in Burkina Faso: status and lessons learnt
The results of Enzyme linked immunosorbent assay tests collected in 2015 on samples of both conventional and Bt varieties in Burkina Faso show the extent of purity loss when inadequate attention is paid to the preservation of seed purity.


Bt Cotton in China: Are Secondary Insect Infestations Offsetting the Benefits in Farmer Fields?
A rise in insecticide use to control mirids between 2001 and 2004 is demonstrated, secondary insect infestations is largely related to the rise of mirids, but this rising did not continue in more than half of sample villages studied in 2004-2006.
Bt-cotton and secondary pests
Bt-cotton seed has been effective to control the damage of bollworm in Chinese cotton production since 1999, reducing the need for pesticides and increasing incomes of Chinese farmers. Field data
Effectiveness and chemical pest control of Bt-cotton in the Yangtze River Valley, China
The chemical control of the Bt-cotton in Yangtze River Valley hence is not optimal, thus farmers are paying high prices for varieties which are not totally resistant to bollworms and pest control costs are not reduced to the extent that they might expect, lowering the profitability of cotton production.
Access and control of agro-biotechnology: Bt cotton, ecological change and risk in China
This article argues that if the introduction of genetically modified crops (GM crops) in developing countries is to be successful, we can and should not evade questions of access and control of
Damage from Secondary Pests and the Need for Refuge in China
It is shown that refuge, while currently used to prevent Bt resistance in the United States, could be used to control secondary pest populations by increasing their exposure to lethal toxins and would be profitable in China.
Biotechnology as an alternative to chemical pesticides: a case study of Bt cotton in China
The overall goal of this study is to determine the extent by which genetically engineered (GE) crops in China can lead to reductions of pesticide use, the nature and source of the reductions, and
Bt Cotton, Pesticides, Labour and Health
This paper describes some of the results of a detailed farm-level survey of 32 small-scale cotton farmers in the Makhathini Flats region of South Africa. The aim was to assess and measure some of the
Second-Generation Bt Cotton Field Trials in Burkina Faso: Analyzing the Potential Benefits to West African Farmers
The model results presented may, in fact, underestimate the profi tability of Bt cotton in Burkina Faso due mainly to the relatively low pest densities encountered at these research sites.
Monitoring and management strategy for Helicoverpa armigera resistance to Bt cotton in China.
  • Kongming Wu
  • Biology, Medicine
    Journal of invertebrate pathology
  • 2007
The results indicate that the field populations are still susceptible to Cry1Ac, and monitoring indication no apparent shifts in susceptibility in field populations of this important pest.
Helicoverpa armigera baseline susceptibility to Bacillus thuringiensis Cry toxins and resistance management for Bt cotton in India.
There is no evidence of development of field-level resistance in H. armigera leading to the failure of Btotton crop anywhere in the world, despite the fact that Bt cotton was grown on the largest ever area of 12.1 million hectares in 2006 and its cumulative cultivation over the last 11 years has surpassed the annual cotton area.