Modeling the invasion of recessive Bt-resistant insects: An impact on transgenic plants

Medvinsky, Alexander B.; Морозов, А.; Velkov, Vassili V.; Li, Bai-Lian; Sokolov, Mikhail S.; Malchow, Horst

doi:10.1016/j.jtbi.2004.06.006

“…The transgenic crops reduce the use of chemical pesticides and are of great benefit to environmental protection. Also, the Bt plant biomass was demonstrated to essentially rely on the duration of the Bt-resistant pest reproduction period (Medvinsky et al, 2004). For instance, a Bt-resistant insect invasion could cause the inhomogenous spatial distribution of crop and pest.…”

Section: Introductionmentioning

confidence: 99%

“…For instance, a Bt-resistant insect invasion could cause the inhomogenous spatial distribution of crop and pest. Also, the Bt plant biomass was demonstrated to essentially rely on the duration of the Bt-resistant pest reproduction period (Medvinsky et al, 2004). Cotton bollworm (Helicoverpa armigera Hübner) is a world-known agricultural pest that feeds on multiple crops, for example, cotton, tomato, capsicum, sunflower, grain sorghum, corn and so on (Zhang & Zhao, 1996).…”

Section: Introductionmentioning

confidence: 99%

Capturing the interaction types of two Bt toxins Cry1Ac and Cry2Ab on suppressing the cotton bollworm by using multi‐exponential equations

Shi

¹

,

Wei

²

,

Sandhu

³

et al. 2015

View full text Add to dashboard Cite

Transgenic crops are increasingly promoted for their practical effects on suppressing certain insect pests, but all transgenic crops are not equally successful. The insect pests can easily develop resistance against single Bacillus thuringiensis (Bt) toxin transgenic crops. Therefore, transgenic crops including two or more mixed Bt-toxins can solve this problem by delaying the resistance development and killing the majority of targeted pests before the evolution of resistance. It is important to test the controlling effects of transgenic crops including multiple mixed toxins on a particular insect pest. Previous research has checked the cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against one susceptible and four resistant strains of cotton bollworm. The results showed that independence was the main interaction type between two toxins for the susceptible strain, whereas synergism was the main interaction type for any one resistant strain. However, the optimal combinations of two toxins were not obtained. In the present study, we developed two multi-exponential equations (namely bi- and tri-exponential equations) to describe the combination effects of two Bt toxins. Importantly, the equations can provide predictions of combination effects of different continuous concentrations of two toxins. We compared these two multi-exponential equations with the generalized linear model (GLM) in describing the combination effects, and found that the bi- and tri-exponential equations are better than GLM. Moreover, the bi-exponential equation can also provide the optimal dose combinations for two toxins.

show abstract

“…To date, such predictions have been the basis for managing resistance to transgenic insecticidal crops and sustainable pest management (Onstad and Gould 1998;Medvinskya et al 2004;Onstad 2008). So far most of the cases of IRM modeling pertain to transgenic crops in developed countries (Onstad 2008).…”

mentioning

confidence: 99%

Modeling Evolution of Resistance byMaruca vitrata(Lepidoptera: Crambidae) to Transgenic Insecticidal Cowpea in Africa

Onstad

¹

,

Kang

²

,

Ba

³

et al. 2012

View full text Add to dashboard Cite

We created a detailed model of the Maruca vitrata (F.) and cowpea [Vigna unguiculata (L.) Walp] system to study the possible evolution of resistance by the insect to transgenic insecticidal cowpea, which is under development. We focused on population dynamics and genetics in a region of west Africa. We simulated single-toxin and pyramided (two-toxin) cowpea and emphasized conservative, worst-case scenarios in our analysis. The results indicate that as long as a pyramided, transgenic cowpea can be developed, seed saving by farmers and reliance on natural refuge are not major problems for resistance management. Furthermore, it is possible that one or both toxins in the pyramid may not need to be high dose for evolution to be delayed significantly (>20 yr or 80 generations for resistance to become a concern if transgenic cowpea is deployed in areas where M. vitrata is endemic). If efforts are made to deploy transgenic cowpea only into the regions where M. vitrata is not endemic, then there is little to no concern with resistance emerging in the M. vitrata population.

show abstract

“…Computer simulations are a powerful tool to predict the likelihood of a pest to evolve resistance to insecticidal toxins. To date, such predictions have been the basis for managing resistance to transgenic insecticidal crops and sustainable pest management (Onstad and Gould 1998;Medvinskya et al 2004;Onstad 2008). So far most of the cases of IRM modeling pertain to transgenic crops in developed countries (Onstad 2008).…”

mentioning

confidence: 99%

Modeling Evolution of Resistance byMaruca vitrata(Lepidoptera: Crambidae) to Transgenic Insecticidal Cowpea in Africa

Onstad¹,

Kang²,

Ba³

et al. 2012

Environmental Entomology

0

View full text Add to dashboard Cite

We created a detailed model of the Maruca vitrata (F.) and cowpea [Vigna unguiculata (L.) Walp] system to study the possible evolution of resistance by the insect to transgenic insecticidal cowpea, which is under development. We focused on population dynamics and genetics in a region of west Africa. We simulated single-toxin and pyramided (two-toxin) cowpea and emphasized conservative, worst-case scenarios in our analysis. The results indicate that as long as a pyramided, transgenic cowpea can be developed, seed saving by farmers and reliance on natural refuge are not major problems for resistance management. Furthermore, it is possible that one or both toxins in the pyramid may not need to be high dose for evolution to be delayed significantly (>20 yr or 80 generations for resistance to become a concern if transgenic cowpea is deployed in areas where M. vitrata is endemic). If efforts are made to deploy transgenic cowpea only into the regions where M. vitrata is not endemic, then there is little to no concern with resistance emerging in the M. vitrata population.

show abstract

Modeling the invasion of recessive Bt-resistant insects: An impact on transgenic plants

Cited by 14 publications

References 34 publications

Capturing the interaction types of two Bt toxins Cry1Ac and Cry2Ab on suppressing the cotton bollworm by using multi‐exponential equations

Capturing the interaction types of two Bt toxins Cry1Ac and Cry2Ab on suppressing the cotton bollworm by using multi‐exponential equations

Modeling Evolution of Resistance byMaruca vitrata(Lepidoptera: Crambidae) to Transgenic Insecticidal Cowpea in Africa

Modeling Evolution of Resistance byMaruca vitrata(Lepidoptera: Crambidae) to Transgenic Insecticidal Cowpea in Africa

Contact Info

Product

Resources

About