(Beyond Pesticides, May 6, 2009) The U.S. Environmental Protection Agency (EPA), in consultation with the U.S. Fish and Wildlife Service (USFWS), is imposing use restrictions for the insecticide methoxyfenozide on cranberries in Wisconsin because of its potential effect on the Karner Blue butterfly. The Karner Blue butterfly is a federally listed endangered species. It remains to be seen whether, short of a ban, the complex and difficult to enforce restrictions on use and application methods will adequately protect the endangered species.
The limitations for methoxyfenozide are contained in a series of county-specific Endangered Species Protection Bulletins (Bulletins) as part of EPA’s Endangered Species Protection Program (ESPP). EPA entered into consultation with USFWS after determining that use of methoxyfenozide on cranberries in Wisconsin may affect the listed Karner Blue butterfly. USFWS recommended a number of use limitations that, when implemented, should result in use that is not likely to adversely affect the Karner Blue butterfly, according to the bulletin. Limitations include not applying the pesticide within the designated pesticide use limitation area, ground applications- only which must be made using a drift retardant and nozzles, and when the wind speed is between 2-10 mph. These limitations are effective within specific areas of several Wisconsin counties: Adams; Burnett; Chippewa; Clark; Eau Claire; Green Lake; Jackson; Juneau; Marquette; Monroe; Polk; Portage; Waupaca; Waushara; and Wood.
In addition to the bulletins that contain instructions for protection of the Karner blue in Wisconsin, EPA also released bulletins for six counties in Michigan (Allegan, Monroe, Montcalm, Muskegon, Newaygo, and Oceana) for protection of the Karner Blue butterfly, and for Door County, WI, for protection of the endangered Hines emerald dragonfly. These additional bulletins however, were not the result of consultation with USFWS; rather they simply implement current methoxyfenozide label restrictions. More information on the limitations is contained in a series of county-specific Endangered Species Protection Bulletins – Bulletins Live! online system that are available on EPA’s Web site at: www.epa.gov/espp/bulletins.htm or by calling 1-800-447-3813. The bulletin system became available for use beginning May 2009. The limitations for the Karner Blue butterfly are contained in the first enforceable endangered species protection bulletin.
In April, the Karner Blue butterfly hatches from eggs that were laid the previous year. About mid-May, caterpillars pupate and adult butterflies emerge from their cocoon-like chrysalis by the end of May or in early June. These adults mate and lay eggs which develop into a second generation of adult butterflies in July. This second generation of adults lay eggs that will hatch the following spring. The butterfly is most widespread in Wisconsin, and can be found in portions of Indiana, Michigan, Minnesota, New Hampshire, New York, and Ohio.
Habitat loss and degradation is a major threat to the butterfly, but the widespread use of pesticides during the spring and summer also impacts their populations. Most insecticides like commonly used pyrethroids (eg permethrin), tubefenozide and diflubenzuron kill many non-target species of moth and butterflies. Genetically engineered plants, including those incorporated with Bacillus thuringiensis (Bt) have adversely affected the Karner Blue butterfly and others like the Monarch butterfly.
Methoxyfenozide is a diacylhydrazine insecticide that mimics the action of the molting hormone of lepidopterous (moths, butterflies) larvae. When ingested, larvae undergo an incomplete and premature molt, which ultimately results in their death. It is used on various agricultural commodities including fruits, vegetables and cotton. It is also associated with hematological effects, liver toxicity and impacts on the thyroid and adrenal glands (endocrine disruption) in laboratory studies. It is very persistent in the environment (half-life ranged from 336 to 1100 days) and can leach to groundwater.
Endangered species continue to be threatened over the continued use of pesticides. However, advocates argue that limitations do not go far enough to protect endangered species. EPA’s lack of enforcement capability, along with a flawed assessment process and pesticide exemption provisions ensure that these vulnerable species continue to be at risk. In 2008, Beyond Pesticides, along with the Natural Resources Defense Council (NRDC)and other environmental and farmworker groups, filed a lawsuit with EPA asking the agency to take immediate action to remedy continuing violations of the Endangered Species Act (ESA) with its continued registration of the pesticides methamidophos, methidathion, oxydemeton-methyl, and ethoprop, which affect threatened and endangered species. Separate lawsuits have also been filed with the USFWS over pesticide use on National Wildlife Refuges, as well as against the National Marine Fisheries Service (NMFS) over the failure to protect salmon and steelhead from pesticides in the Pacific Northwest. In this case, the NMFS found that three pesticides — carbaryl, carbofuran, and methomyl – jeopardize the existence of protected salmon and steelhead, and mitigation measures, including buffer zones for aerial spraying and prohibition of spraying when wind speeds are greater than 10mph, were recommended. The pesticides chlorpyrifos, diazinon, and malathion were previously identified as being a threat to salmon and steelhead as well.
For more information on pesticides and endangered species visit EPA.
Source: EPA Bulletin