Study shows worms can develop pesticide resistance in as little as 80 days

| 2nd February 2009
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The pesticide industry knows all too well that nature quickly develops immunity to its chemical armoury. But a new study by scientists at the Instituto Gulbenkian de Ciencia (IGC) and the Faculty of Science of the University of Lisbon, in Portugal has shown that a species of worm can develop resistance to a common pesticide in just 20 generations, or 80 days.

The researchers dosed Caenhorabditis elegans worms with Levamisole, a widely-used pesticide which acts on the nervous system. True to form, the toxin worked quickly, reducing the fertility and survival rates of male worms. However the population survived because the worms are hermaphroditic and some members contain both male and female sexual organs, and adapted to the presence of the pesticide.

By the 10th generation fertility had recovered and by the 20th generation numbers had increased once more.

This article first appeared in the Ecologist December 2008

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