Mosquito Fogging Kills Hundreds of Bees
(Beyond Pesticides, August 19, 2015) Local fogging for mosquito control turned tragic for a Palo Alto, California beekeeper who lost hundreds of honey bees from his backyard hives. The beekeeper, who also produces organic honey, now fears his honey is contaminated. The fogging, which occurred last month, was in response to positive tests for West Nile virus in mosquito samples. Many mosquito control pesticides are toxic to honey bees and given the declining populations of pollinators, vector control officials are being asked to carefully consider the risks associated with pesticide spraying.
According to the local NBC affiliate, beekeeper Rondolph Tsien believes he was not given sufficient time to protect his bees from the mosquito fogging and, despite trying to cover his hives with a tarp to protect his bees from drifting pesticides, many were lost.
A mosquito sample tested positive for West Nile virus about one mile from Mr. Tsien’s home, putting his property in the catchment area for fogging. Mr. Tsien worries the surviving bees will produce contaminated honey that can no longer be labeled organic.
A Santa Clara County Vector Control representative stated during an interview that the county uses an “extremely low dose” of pesticides during fogging and are only sprayed “when necessary.” But recent scientific data finds that even extremely low doses of pesticides can negatively impact bee behavior, even causing death. On its information page, the county notes that it uses the insecticide etofenprox (Zenivex), a pyrethroid-ether insecticide in the pyrethroid class that is known to be highly toxic to honey bees. Ground and aerial pyrethroid applications for mosquito control result in in-situ and off-site exposures. Pyrethroids, due to their toxicity to bees, are thought by some researchers to be a major contributor to the significant decline in bee populations after neonicotinoids. In fact, some scientists are finding that honey bees’ olfactory receptor neurons, which are responsible for inter-individual communication, are affected by pyrethroid exposures.
Studies find that sublethal concentrations of the pyrethroids can significantly reduce bee fecundity and decrease the rate at which bees develop to adulthood and reproduce. Several field and laboratory studies using pyrethroids have consistently documented decreases in foraging activity and activity at the hive entrance after exposure. In addition, pyrethroids like etofenprox are suspected endocrine disruptors, have been linked to certain cancers, and are particularly dangerous to aquatic life even at low concentrations.
Mr. Tsien’s concerns about contaminated honey are well founded. A wide array of pesticides has been detected in hives, wax, pollen, and honey. Formal recommendations by the National Organic Standards Board (NOSB) to the National Organic Program in 2010 on organic apiculture state that organic standards should prohibit producers from foraging in areas where there is “a significant risk of contamination by prohibited materials within a 1.8 mile (3 kilometer) radius of the apiary,” in order to avoid risks of honey bee exposure and contamination of honey due to pesticides.
Pesticides like neonicotinoids, a class of insecticides highly toxic to honey bees, have been receiving public attention as a result of their widespread use in agriculture, environmental contamination, and overwhelming scientific evidence of their role in pollinator decline. Neonicotinoids are systemic (moving through the vascular system of the plant and expressed through pollen, nectar and guttation droplets) and persistent.
There are, however, safer and more effective alternatives to pyrethroid-based mosquito control, given that these spray programs are of very limited efficacy. In a study published in theJournal of Agricultural and Environmental Ethics, Cornell University professor of entomology David Pimentel, Ph.D. calculated that less than .0001 percent of ultra low volume (ULV) pesticide sprays reach target insects. Further, along with vulnerable honey bees, people with compromised immune systems, chemically sensitized people, pregnant women, and children with respiratory problems, such as asthma, are particularly vulnerable to these pesticide spray programs and will suffer disproportionately from exposure.
Beyond Pesticides believes the ideal mosquito management strategy comes from an integrated approach that emphasizes education, aggressive removal of standing water sources, larval control, monitoring, and surveillance for both mosquito-borne illness and pesticide-related illness. Control of disease-carrying mosquitoes can be successful when the emphasis is placed on public education and preventive strategies. Individuals can take action by eliminating standing water, introducing mosquito-eating fish, encouraging predators, such as bats, birds, dragonflies and frogs, and using least-toxic larvacides like bacillus thuringiensis israelensis (Bti). Community-based programs should encourage residents to employ these effective techniques, focus on eliminating breeding sites on public lands, and promote monitoring and action levels in order to determine what, where, and when control measures might be needed. Through education of proper cultural controls, and least-toxic and cost effective biological alternatives, the use of hazardous control methods, such as toxic pesticides, can be eliminated.
For more information on safe and effective mosquito management strategies, see Beyond Pesticides’ page on Mosquitoes and Insect Borne Diseases, or contact us at info(at)Beyondpesticides.org.
Let’s BEE Protective and support a shift away from the use of these toxic chemicals by encouraging organic methods and sustainable land management practices in your home, campus, or community.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: NBC Bay Area