by Staff Writers
Puyallup, WA (SPX) Mar 13, 2012
A Washington State University toxicologist has found that three commonly used herbicides can dramatically reduce butterfly populations. The research was aimed at possible effects on the Lange's metalmark, an endangered species in northern California, but it has implications for other at-risk and endangered butterflies wherever herbicides are used, says John Stark, an ecotoxicologist and director of the WSU Puyallup Research and Extension Center.
Stark and his colleagues tested triclopyr, sethoxydim and imazapyr on butterfly larvae at the request of the U.S. Fish and Wildlife Service, which uses the herbicides to maintain habitat for the Lange's metalmark in its last habitat, the Antioch Dunes National Wildlife Refuge in northern California. The researchers used the Behr's metalmark as a proxy for the Lange's metalmark, whose endangered status precludes using it for tests.
The researchers found adult numbers of the Behr's metalmark butterfly dropped by one-fourth to more than one-third when their larvae were exposed to regularly applied rates of the herbicides.
In a small population of endangered animals, says Stark, "any kind of reduction like that is going to be a problem."
While the dunes may have harbored 25,000 Lange's metalmarks 50 to 100 years ago, damage to the dunes reduced the population to 5,000 by 1972 and as low as 45 in 2006.
Key to the butterfly's survival is the naked stem buckwheat plant, which is easily overgrown by the non-native plants ripgut brome, vetch and yellow starthistle.
Refuge managers have tried to weed by hand but the process risks disturbing the buckwheat plants and butterfly eggs and larvae. And when the refuge managers started spraying the plants with herbicides, they noticed the butterfly populations were dropping even more, says Stark.
The study, funded by the Fish and Wildlife Service and published in the journal Environmental Pollution, is one of the first to document the effects of herbicides on butterflies. Several studies have shown herbicides can adversely affect animal life, even though they are designed to kill plants.
Each of the three herbicides in the Stark study operate differently, leading the researchers to think butterflies are being affected by inert ingredients or an effect on the butterflies' food source.
Washington State University
Farming Today - Suppliers and Technology
Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.
World breakthrough on salt-tolerant wheat
Adelaide, Australia (SPX) Mar 13, 2012
A team of Australian scientists has bred salt tolerance into a variety of durum wheat that shows improved grain yield by 25% on salty soils. Using 'non-GM' crop breeding techniques, scientists from CSIRO Plant Industry have introduced a salt-tolerant gene into a commercial durum wheat, with spectacular results shown in field tests. Researchers at the University of Adelaide's Waite Research ... read more
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2012 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement|