How Bt crops work, until they stop working

Some of the most popular GM (genetically modified, also called genetically engineered, GE) crops are called Bt crops. That means they make an insecticide (Bt toxin) in the plant’s own tissues. So the farmer doesn’t need to spray insecticide. At least, that’s the aim. The not-for-profit International Service for the Acquisition of Agri-biotech Applications (ISAAA) explains how Bt crops work. Scroll down that page if you want to see what Bt crops are being grown.

How well does this work in practice? How soon do insect pests evolve resistance to the toxin? What can farmers do to get the best out of Bt crops? Another not-for-profit, Plantwise, tells us about insects evolving resistance to Bt toxin and farmers’ responses to that.

In practice, some farmers increase their use of insecticide spray when they’re growing Bt crops. That’s not the aim of making or growing these crops. But sometimes, it’s what happens.

[Edit] My fellow blogger Daniela at The Noah Project tells us about the Western corn rootworm (Diabrotica virgifera virgifera) evolving resistance to Bt toxin. A gene called Cry 3Bb was inserted into these corn (maize, Zea mays) plants, so that they make Bt toxin. But the canny little rootworms fought back.

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About argylesock

I wrote a PhD about veterinary parasitology so that's the starting point for this blog. But I'm now branching out into other areas of biology and into popular science writing. I'll write here about science that happens in landscapes, particularly farmland, and about science involving interspecific interactions. Datasets and statistics get my attention. Exactly where this blog will lead? That's a journey that I'm on and I hope you'll come with me.
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4 Responses to How Bt crops work, until they stop working

  1. Pingback: Playing the long game for GM in Europe | Science on the Land

  2. Pingback: Pest evolves better resistance to insecticidal GM crops | Science on the Land

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