   Bark Beetles and Pesticides - March 26, 2003 Jeff Schalau, County Director, Agent, Agriculture & Natural Resources Arizona Cooperative Extension, Yavapai County As recent climatic events unfolded, bark beetles and the mortality caused their activity has become an increasing concern. In responding to the educational needs of northern Arizona residents, I have offered several educational seminars and provided information on the Internet. Yet, much of my time and energy is spent trying to correct misinformation related to pesticides and their use to "control" or protect trees from bark beetles. As an educator for the University of Arizona, I utilize peer-reviewed, research-based information and the Federal and State laws/regulations that govern the use of pesticides. The information below is what I use to disseminate the best available science to the public. No pesticide may be sold in the United States until the U.S. Environmental Protection Agency (EPA) has reviewed the manufacturer's application for registration and determined that the use of the product will not present an unreasonable risk to humans or the environment. Only after the EPA has reviewed the labeling and registered the product can a pesticide product be sold. According to the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), it is illegal to use a pesticide in any way not permitted by the labeling. A pesticide may be used only on the plants, animals, or sites named in the Directions for Use. You may not use higher dosages, higher concentrations, or more frequent applications. A person may apply a pesticide against any target pest not listed on the labeling if the application is to a plant, animal, or site that is listed under Directions for Use. There are no pesticides labeled or proven effective for killing bark beetles that have already colonized ponderosa pine, pinyon pine, Arizona cypress, Leyland cypress, or juniper trees. This includes microinjection insecticides. Furthermore, beware of companies that claim their organic treatment or fertilizer will prevent attack by bark beetles. Note: I would be happy to review any peer-reviewed, scientific research that indicates otherwise. Three pesticides are labeled for prevention of colonization by Ips and Dendroctonus bark beetle species. These pesticides contain the active ingredients are carbaryl (trade name Sevin SL) or permethrin (trade names Astro and Dragnet). These active ingredients are present in several other trade name pesticides. However, these other products are not formulated or registered for use on bark beetles. The pesticides recommended above coat the bark and act as a stomach poison to beetles that chew into the bark where it is coated. Note: pesticide labels are legally binding documents and all pesticides must be applied in compliance with product label directions. Scientists at the University of Arizona, Northern Arizona University, and the US Forest Service Rocky Mountain Research Station have reviewed the information presented above. New research projects are being initiated to test other products and their effect on bark beetles. New research must be scientifically designed, conducted in an un-biased manner, statistically valid, and peer-reviewed. This is the scientific method of generating new knowledge. If it does not pass these tests, then it is anecdotal evidence and cannot be relied upon. I encourage readers to learn more about northern Arizona bark beetles. I will share any new information that becomes available. For more information about bark beetles, visit the Forest Health page on the Yavapai County Cooperative Extension web site at: cals.arizona.edu/yavapai/. Naming of companies or products is neither meant to imply endorsement by the author nor criticism of similar companies or products not mentioned. The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at mgardener@verdeonline.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://cals.arizona.edu/yavapai/anr/hort/byg/. |