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PESTICIDE BRIEFS (4/3/02) CONTENTS:
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CAN CLOPYRALID CONTAMINATE COMPOST?
 Due to the escalating costs of defending fenamiphos relative to its limited use, Bayer has requested voluntary cancellation of all uses of fenamiphos effective May 31, 2005. On this date Bayer will stop manufacture, sale, and distribution of fenamiphos. However, dealers will be able to continue to sell and users use the respective Nemacur products as long as they remain in the channels of trade, without limitation. On February 12, 2002, EPA announced a voluntary decision by industry to move consumer use of treated lumber products away from a variety of pressure-treated wood that contains arsenic by December 31, 2003, in favor of new alternative wood preservatives. This transition affects virtually all residential uses of wood treated with chromated copper arsenate, also known as CCA, including wood used in play-structures, decks, picnic tables, landscaping timbers, residential fencing, patios and walkways/boardwalks. By January 2004, EPA will not allow CCA products for any of these residential uses. This decision will facilitate the voluntary transition to new alternative wood preservatives that do not contain arsenic in both the manufacturing and retail sectors. Although EPA has not concluded that there is unreasonable risk to the public from these products, they do believe that any reduction in exposure to arsenic is desirable. For questions & answers on CCA treated wood, go to: http://www.epa.gov/pesticides/citizens/cca_transition.htm EPA has published a proposed rule to revoke 72 tolerances for residues of the insecticides methyl parathion and ethyl parathion. The 72 tolerances are proposed for revocation because there are no registered uses for methyl parathion or ethyl parathion on these commodities. All uses of ethyl parathion have been canceled. There are 25 remaining crop uses for methyl parathion; the 29 tolerances associated with these uses are not proposed for revocation. The notice lists the tolerances proposed for revocation and is available on EPA's web site at: http://www.epa.gov/fedrgstr/EPA-PEST/2002/February/Day-06/p2513.htm Comments on these proposed tolerance revocations will be accepted until April 8, 2002, and must be submitted as described in the Federal Register notice, identified by docket number OPP-301195. If EPA receives a request to retain a tolerance, they will publish a notice regarding data that must be submitted to demonstrate that the current safety standard is met and the schedule for submission of the data. EPA believes that affected commodities should have cleared channels of trade before the proposed effective dates of these tolerance revocations. Commodities containing pesticide residues not covered by a tolerance are considered to be adulterated and are subject to seizure. A tolerance must meet the current safety standard established under the Food Quality Protection Act if it is to be retained. (See http//:www.epa.gov/pesticides/tolerance for status and other information on tolerance reassessment.) RETURN TO TOP EPA has issued the interim risk management decision documents for the organophosphate pesticide acephate. Acephate is an insecticide currently registered for use on a variety of field, fruit, and vegetable crops (e.g., cotton, tobacco, cranberries, mint, sod); on ornamental plants both in greenhouses and outdoors (e.g., nonbearing fruit trees,Christmas trees, and cut flowers); on golf courses; and in food-handling establishments, hospitals, hotels and other public areas for pest control. Based on risk assessments conducted on this pesticide, EPA has concluded that acephate does not pose risk concerns in food or drinking water. By eliminating indoor residential uses and all turf uses except golf courses and sod farms, the aggregate risk from acephate fits in its own risk cup. Other risk mitigation measures will be implemented to reduce worker and ecological risks below levels of concern for reregistration. For example, for certain uses, some application methods will be eliminated and application rates will be lowered. Labeling to protect honeybees will be required, as will labeling to reduce potential spray drift. Details of these and other risk mitigation actions are found in the full interim risk management decision document. Further mitigation of acephate uses may be necessary to reduce risks from methamidophos residues that result from acephate applications, since acephate forms methamidophos as a breakdown product. Once the methamidophos IRED is complete, EPA will determine whether the methamidophos exposure resulting from acephate use poses risk concerns. Any potential further mitigation will be discussed at the time the methamidophos IRED is released. EPA is currently completing the cumulative
risk assessment for the organophosphorus pesticides and will complete the
reregistration decision for acephate after consideration of cumulative
risks. The Federal Register notice announcing the availability of
this decision can be found on EPA's web site at: http://www.epa.gov/fedrgstr/EPA-PEST/2002/January/Day-30/p2238.htm
The following information was sent from EPA to all Pesticide Coordinators in the Region Regarding Insecticide Applications on Mixed Stands of Alfalfa: In the summer of 2001 the Vermont Department of Agriculture and several other states became involved in investigating possible misuse of insecticides for armyworm control on pastures. These investigations brought to light a number of questions regarding the applicability of label terms to the sites where applications had been made to mixed stands of alfalfa. For example, insecticides were used on alfalfa, for which they were labeled, and on grasses, for which they were not. EPA's response was that each component of a pasture crop does need to have a tolerance and be identified on the label as a use site. Thus, application of a product registered for alfalfa only to a mixed stand of alfalfa/clover/grass would be a use inconsistent with the label, irrespective of the percentage of the stand consisting of alfalfa. EPA recognizes that only a few products registered only for alfalfa currently include the appropriate label instruction: "Apply only to fields planted to pure stands of alfalfa". EPA plans to notify and require registrants of products labeled for use on alfalfa to clarify their labels by incorporating the above limitation when there is only an alfalfa tolerance. At the same time EPA plans to encourage registrants to petition for a crop group tolerance for grasses that would cover all the forage grasses. However, since this will not happen in time for this use season and we will likely see alfalfa weevil and other pest damage in mixed stands, it will be important to only use products labeled for mixed stands. The only insecticides with tolerances and a labels on alfalfa/clover/grass mixtures that may be effective against alfalfa weevil and other pests include carbaryl (Sevin 80S, Sevin XLR), and malathion. Lannate only has a label for Bermudagrass pastures. By Dewey M. Caron, University of Delaware The honey bee industry has been very negatively
impacted by a varroa mite which transferred relatively recently from an
Asian species of Apis to the managed western bee Apis mellifera. The A.
mellifera host-parasite is not a "good" one as the varroa mite is
responsible for causing loss of entire colonies, probably by facilitating
entry of pathogens into the honey bee body as it feeds on both adult and
larval hemolymph after puncturing the exoskeleton. Colony losses were especially
heavy (50% range) in the winters of 1995-1996 and 2000-2001. My early survey
analysis indicates this past winter losses were about 20%.
With appearance of the mite in the U.S.
in 1987, beekeepers quickly adopted miticide treatment with use of the
pyrethroid fluvalinate to protect colonies. Treatment using hive strip
inserts (Apistan) was relatively cheap and convenient, although commercial
beekeepers purchased Mavrik and doctored their colonies in this unregistered
manner. Wellmark Industries put out ads about the dangers of misuse of
Apistan (not following directions, leaving strips in too long, reuse of
strips, etc) after hearing of such practices and to warn about resistance
development. Fluvalinate resistance began to appear in Europe eight
years ago and in the U.S. about four years ago when Bayer began to market
their livestock organophosphate coumaphos under Section 18 formulated in
convenient strips as Checkmite+.
This spring Richard Hack, Product Manager
of Bayer Corporation (the manufacturers of Checkmite+ strips) sent this
communication to beekeepers regarding illegal use of Checkmite+:
"I am writing to inform you of concerns communicated to us by state and federal regulatory agencies regarding beekeepers not following label directions with the use of Checkmite+ Bee Hive Pest Control Strips. Bayer Corp and beekeepers have worked together to request and obtain Section 18 Emergency Exemptions. Such registration provides beekeepers with an effective treatment for hives infested with varroa mites and /or African hive beetles.In our regional MAARC (Mid-Atlantic Apiculture Research and Extension Consortium) newsletter BeeAware [I will be glad to send copy to any who request it] I printed his letter and included the following postscript: Comments from Dewey Caron - We do not recommend colony treatment with the organophosphate Checkmite+ unless monitoring reveals high mite levels and Apistan resistance has been demonstrated in your bees. Our MAAREC IPM approach is to apply various non-chemical mite suppression methods during the season and to check colony levels in late summer (August) to determine if colony and/or apiary treatment with a miticide is warranted. Rechecking mite levels post-treatment is also advisable. |
