Washington: Getting rid of pesky insects, such as mosquitoes, ants and roaches may be fraught with adverse consequences, depriving plants of their taste and high yield, suggests a new study.
Specifically, it showed that evening primroses grown in insecticide-treated plots quickly lost, through evolution, defensive traits that helped protect them from plant-eating moths.
These results indicate that once the plants no longer needed their anti-insect defences, they lost these. What's more, they did so quickly -- in only three or four generations, the journal Science reported.
Anurag Agrawal, professor of ecology and evolutionary biology at Cornell University, who led the study, explained: "We demonstrated that when you take moths out of the environment, certain varieties of evening primrose were particularly successful.
"These successful varieties have genes that produce fewer defences against moths."
Subsequently, the evening primroses seemingly stopped investing energy in their anti-insect defences, which disappeared through natural selection, according to a Cornell statement.
Agrawal said that he was "very surprised" by how quickly this process occurred, and that such surprises "tell us something about the potential speed and complexities of evolution".
"In addition, experiments like ours that follow evolutionary change in real-time provide definitive evidence of evolution."
Besides, oils produced by evening primroses have been used medicinally for hundreds of years and are beginning to be used as herbal remedies.
Agrawal's insights about pests that attack these plants and about chemical compounds produced by these plants may ultimately be useful to the herbal and pharmaceutical industries.
First Published: Saturday, October 06, 2012, 11:06