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Question

The Brazilian ministry of agricultural development is warning farmers that GM Bt crops, pesticides, and monocultures are responsible for the plague of caterpillars that is devastating the country's agriculture.
According to the general coordinator of Risk Management and Rural Security of the Office for Family Farming of the Ministry of Agrarian Development (SAF/MDA), José Carlos Zukowski, the biggest problem occurs in areas of extensive monoculture - vast expanses of the same type of plant.
"Where there have been big advances of monoculture and the intensive use of pesticides, there are no suitable conditions to develop insect predators that fight the caterpillar, which would be a form of natural biological control. Where there is a mixture of different crops, non-transgenic crops without the Bt toxin and native vegetation, there is just no space for the predators to develop, which are important to combat the plague [of caterpillars]," he explains. "Simply using these products tends to generate greater resistance. There may even be an effect of combatting [the pest] at first, but then it becomes ineffective.”
How do you respond to the claim that Bt toxins and other pesticides are creating super resistant caterpillars, similar to “superweeds”?

Submitted by: Transparency


Answer

Expert response from Community Manager

Moderator for GMOAnswers.com

Friday, 14/03/2014 18:00

Thanks for your question. Plant genetics and breeding expert Daniela Brioschi recently provided insight into the pest infestation in Brazil that might be of interest to you. To answer your question about pest resistance, please see this excerpt from her response:

Why is the pest pressure more intense this crop season?

“Three factors contributed significantly to the occurrence of the infestation. The first is related to weather conditions, which in the 2011–2012 and 2012–2013 crop seasons were atypical. The drought favored the survival of larvae in the 2011–2012 crop season, which found suitable climatic conditions to complete their development cycle and thus ensure their survival and population increase.

“The second factor can be assigned to sequential and simultaneous planting of host crops (such as maize, soybeans and cotton). Thus, these areas provide food, shelter and abundant breeding sites for the pests.

“The third factor refers to the absence of adequate monitoring, which allows early identification of pest infestations. Detection of populations at the beginning of the infestation is essential for effective control, given that commercial insecticides and Bt plants are currently more effective in worms in early stages of development.


Why was Bt technology unable to control pest attacks?

“Each technology is developed for one or a group of specific pests, and each Bt trait shows different levels of control for different target species. It is important to mention that researchers from the Empresa Brasileira de Pesquisa Agropecuária [Brazilian Agricultural Research Corporation] (Embrapa) have found that one of the worms attacking cotton, corn and soybean crops in various regions is the Helicoverpa armigera, which had not yet been found in Brazil. The identification of the pest was done through morphological analysis (from genitalia—undertaken by researcher Alexandre Specht, Embrapa Cerrados) and through molecular analysis (conducted by Daniel R. Sosa-Gomez, Embrapa Soja).

“The Helicoverpa armigera is regarded as an A1 quarantine pest. This classification is given for exotic pests not present in the country, which can cause significant economic damage. The lack of correct identification of the pest population worsened the outbreak, as the registered insecticides and commercial Bt plants available in the country did not consider this species a target pest.

“With the identification of the quarantine pest, the Agriculture Defense Department of the Ministry of Agriculture, Livestock and Supply (MAPA), authorized on an emergency basis the import and application of products that have emamectin benzoate as the sole active ingredient. The use of this compound is authorized in over 40 countries, including Portugal, Spain, Italy, France, the Netherlands, the United States and Australia.”

A link to Dr. Brioschi’s full response is available here: http://gmoanswers.com/clarifications-pest-infestations-brazil-0.