As bugs become resistant to Bt maize in South Africa, new practices needed to delay resistence


In the case of maize, the GM crops planted and consumed in South Africa are known as Bt-crops, so named because they contain a protein (Bt) produced by a common soil bacterium, Bacillus thuringiensis. The protein is the bacterium’s weapon against hungry bugs; when they digest it, they die.

A key environmental concern is the development of insects resistant to Bt-protein. In much the same way that doctors fear drug-resistant strains of major diseases, which could see antibiotics rendered useless, agriculturalists fear the appearance of such ‘super-bugs’. This is already becoming a problem in South Africa. However, arguing that GM should be summarily ditched due to the possibility of Bt-resident bugs becoming widespread is akin to arguing that we should abandon use of antibiotics in case drug-resistant disease strains emerge. What the emergence of super-bugs in this country does highlight is the importance of regulations requiring farmers to plant non-GM maize strips alongside Bt-crops. These ‘refuges’ areas, where stem-borers can feed, have been shown to delay resistance build-up in nearly all target insects. Due to a similar lack of knowledge in the farming community about GM crops, compliance by South African farmers is particularly low. Fortunately, this problem is correctable.

The South African National Biodiversity Institute (Sanbi) recently released a report on the environmental impacts of GM maize in South Africa. As well as highlighting the importance of refuge compliance, the report identified other environmental concerns, including gene flow to non-Bt fields.

The GLP aggregated and excerpted this blog/article to reflect the diversity of news, opinion and analysis. Read full, original post: SA’s genetically modified maize: Here’s what you should know about it