May 12, 2016: The Smart on Pesticides Coalition shares the Bee Informed Partnership (BIP) concerns regarding their latest preliminary results of an annual nationwide survey that “Beekeepers across the United States lost 44 percent of their honey bee colonies during the year spanning April 2015 to April 2016.” As BIP’s project director, Dr. Dennis VanEngelsdorp notes, “We’re now in the second year of high rates of summer loss, which is cause for serious concern.”
The Smart on Pesticides Coalition is however, troubled by BIP’s conclusions regarding causation of continued losses, as stated on the BIP website. While there is agreement that Varroa mite “is closely linked to several damaging viruses causing bee colony losses,” BIP fails to note that neonicotinoid pesticides (neonics) weaken bee immune systems making them more susceptible to infestations such as the Varroa mite and appears to blame the prevalence of the Varroa mite’s impact on beekeeper mismanagement without providing any science that supports their claim.
The Bee Informed Partnership produces a voluntary survey, which asks questions of beekeepers, but does not test why bees died. It involves no testing for pesticides. It is a way to estimate colony losses and asks beekeepers to guess at the causes of their hive mortality. Complete survey results have not been made public, including beekeepers’ answers to survey questions.
Honeybees, as well as other pollinators, are facing four major challenges: pesticides, parasites, diseases, and habitat loss. The Varroa mite is a contributing problem, both as a parasite and a vector for diseases.
Neonicotinoid pesticides exacerbate the other challenges pollinators face. We know neonics weaken the immune systems of honeybees, making them more likely to succumb to diseases carried by Varroa mites and other parasites. Previously benign viruses and parasites causing minor damage, become killers to bees affected by neonics. Neonics at field-relevant doses are found to suppress the immune system that lead to death of honeybees. (De Prisco et.al. 2013). This was also noted earlier in 2010, in the work of Alaux and Pettis (USDA Beltsville Bee lab).
In April 2015, the European Academies Science Advisory Council, referring to the results of Di Prisco et al, concluded “that neonicotinoids cannot be considered as the only ‘cause’ of Colony losses, but they can aggravate the impact of viral pathogens, stably associated with honeybee colonies all over the world.”
Dr. Klaus-Werner Wenzel, a member of the Task Force on Systemic Pesticides, has stated that there is “no scientific evidence that Varroa mite can kill a healthy bee colony”. France had Varroa in every hive in the country from 1968 until 1994 without any instances of mass colony deaths. But the year in which neonics were introduced, Varroa turned from a ‘problem parasite’ to a colony killer.
Removing Varoa mites is not the complete answer. If we are going to break this disturbing trend of pollinator losses we must better protect bees from pesticides, specifically neonicotinoids, and we must encourage habitat renewal.
Beekeepers have been controlling Varroa mites since their arrival in 1986. Even hobbyists are well versed in mite life cycle, behavior, and evolving treatment modes. Blaming backyard beekeepers for not treating mites and infecting “good beekeepers” ignores other known causal factors. It is disturbing that these statements are made without any conclusive scientific data to back up the claim. Furthermore, well-respected studies show the same high mortality in wild bees exposed to neonicotinoids–yet these species are not affected by Varroa mite. Managing mites will not help other pollinators who are also in dramatic decline.
The fact that bees are dying in summer, when they should be thriving, underscores the severity of the problem. There is no question that bees and other pollinators are struggling. And while several factors are at play, exposure to harmful neonicotinoids is something within our control. Maryland legislators have acted responsibly to reduce unnecessary neonicotinoid exposure by passing the Maryland Pollinator Protection Act.
The Smart on Pesticides Maryland coalition, spearheaded by the Maryland Pesticide Education Network, works to protect Marylanders and the natural systems we depend upon from the toxic impacts of pesticides. The coalition includes more than 75 organizations, and institutions representing communities, businesses, health care providers, farmers, environmentalists, Waterkeepers, interfaith congregants as well as environmental justice, public health and wildlife advocates.