04
Apr
Pesticides Kill Dragonflies and Reduce Biodiversity in Rice Paddies
(Beyond Pesticides, April 4, 2016) Pesticides widely used in rice paddies in Japan are harming dragonflies. The study, conducted by researchers at Japan’s National Institute for Environmental Studies, finds that the insecticide fipronil significantly reduces the population of adult dragonflies, more so than any other pesticide treatment.
The study, titled Fipronil application on rice paddy fields reduces densities of common skimmer and scarlet skimmer and published in the journal Scientific Reports, investigated the impact of neonicotinoids, which have been linked to bee die-offs around the world, and chlorantraniliprole, which, like neonicotinoids and fipronil, is a systemic pesticide that is taken up by the plant and subsequently expressed in pollen, nectar, and guttation droplets. Plankton species were adversely affected by clothianidin, a neonicotinoid, and chlorantraniliprole, but they recovered after concentrations of the chemicals decreased.
Koichi Goka, Ph.D., a senior researcher at the institute, said nymphs living near the soil are particularly vulnerable to toxic chemicals, according to The Asahi Shimbun. “The density of insecticidal components in the water drops quickly after they are dissolved,” Goka said. “But such components long remain in the soil. Nymphs at the bottom of water could have been affected.”
Dr. Goka is calling for more testing in outdoor facilities to assess the risks of agricultural chemicals.
Dragonflies and other pollinators are under constant threat from the widespread use of pesticides. A study published in March 2016 found over 50 different types of pesticides in honey bees, including neonicotinoids, pyrethroids, and fipronil, while investigating over 70 honey bee poisoning events. A 2013 study published in the Proceedings of the National Academy of Sciences found that pesticide use has sharply reduced the regional biodiversity of stream invertebrates, such as mayflies and dragonflies, thus posing a long-term threat to important ecosystems.
Plan to attend Cultivating Community and Environmental Health, the 34th National Pesticide Forum, April 15-16, 2016 in Portland, ME to discuss pollinators and other local and national environmental concerns. Jonathan Lundgren, Ph.D., a senior USDA entomologist will join other top scientists and leaders who have stood up to protect human and environmental health, despite facing industry backlash and scientific suppression. Dr. Lundgren’s research on the harm that neonicotinoids pose to monarch butterflies reflects a growing scientific consensus that these chemicals present significant risks to declining pollinator populations. Registration, which includes access to all sessions as well as organic food and beverages, is $45 for grassroots activists, and $25 for students. Register online today.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Sources: The Asahi Shimbun
