A group of scientists at the University of Arizona have this week published a paper in Nature Biotechnology on the evolution of resistance in insect pests populations to insecticidal proteins from Bacillus thuringiensis (Bt) that are produced by transgenic crops. Resistance is defined as the phenotype of an individual that gives the individual the ability to survive on a transgenic insecticidal plant from egg to adult and provide viable offspring. The team analysed field and laboratory data from seventy-seven studies of thirteen pest species in eighteen countries across five continents. Entomologist Bruce Tabashnik and colleagues found well documented cases of field-evolved resistance to Bt crops in five major pests as of 2010. 60% of these cases occurred in the U.S.A, where approximately half of the world’s Bt crop acreage is planted. In some cases, resistance to Bt evolved within as little as two to three years, whilst in other cases Bt crops have remained effective for more than 15 years. The research team aimed to better understand how quickly insect populations are evolving resistance to Bt crops and how this is occurring.
Eggplant or aubergine (Solanum melongena) is a crop often attacked by the Colorado Potato Beetle (Leptinotarsa decemlineata), a major insect pest of plants from the Solanaceae family including potato, tomato and eggplant throughout North America, Europe and Asia. This insect pest is exceptionally destructive to crops and readily develops resistance to a wide variety of chemical insecticides, making research into alternative control methods vital. Now new research has revealed that the use of clover cover crops in agricultural fields of eggplants may provide an economically and ecologically viable method of Colorado Potato Beetle management that is as effective as chemical insecticides in regulating the beetle populations.