OSAKA -- Herbicides that don't harm insects can still reduce the population of damselflies living among waterweeds in rice fields, according to the findings of a team led by researchers at Kindai University.
A team member said, "The findings will enable people to predict the risk of agricultural chemicals such as herbicides on creatures." While it had been previously revealed that rice field insecticides can also kill some non-targeted insects, the effects of herbicides were unknown, according to the researchers.
In the experiment conducted in a large water tank designed to reproduce the rice field ecosystem, larvae of a damselfly species that resides among waterweeds decreased by 50% when herbicides were introduced. The result is thought to stem from the death of the waterweeds.
Daisuke Hayasaka, an associate professor of ecotoxicology at Kindai University, said, "It's possible to reveal the connection between the amount of agricultural chemicals used and the damage to the ecosystem, to find measures to minimize their influence."
The results of the study have been published in the online science journal Ecological Applications.
(Japanese original by Ryo Watanabe, Osaka Science & Environment News Department)