Other Pesticides Found to Affect Bee Health
“Crop pollination exposes honey bees to pesticides which alters their susceptibility to the gut pathogen Nosema ceranae,” released in PLOS ONE this week is what beekeepers have suspected. The researchers found high fungicide loads in pollen along with thirty-five different pesticides. The six researchers involved in this study are diverse, from the USDA and universities across the U.S., providing valuable information to the discussion on pesticides, fungicides, and bee health. Their research showed an “increased probability of Nosema infection in bees that consumed pollen with a higher fungicide load.” This research further examines the real-world experiences of managed honey bees, and the effects of pesticide mixtures on bee health.
The researchers worked with beekeepers who were providing crop pollination services in California, Pennsylvania, Maine, New Jersey, and Delaware. Pollen was collected from hives pollinating seven major crops: pumpkin, watermelon, cucumber, cranberry (early and late season) blueberry, and almonds. The pollen was analyzed to determine field- relevant pesticide exposure, and how the pesticides affected bees’ susceptibility to Nosema ceranae. Pollen samples contained an average of nine different pesticides, with a high of twenty-one pesticides.
Pollen collected was not always from the crop the bees were to pollinate, yet all of the pollen contained pesticides. Even honey bees able to find wild flowers or weeds bordering agriculture, found pesticides in those plants as well. “The maximum pesticide concentration in any single pollen sample exceeded the median lethal dose (LD50, the dose required to kill half a population within 24 or 48 h) for esfenvalerate and phosmet.” The research found the presence of two specific fungicides in pollen—chlorothalonil and pyraclostrobin were significantly correlated with a higher rate of Nosema infection among bees fed that pollen.
“Nosema infection was more than twice as likely to occur in honeybees that consumed pollen containing fungicides,” noted the researchers. Pyraclostrobin actually increased the risk of being infected by Nosema three-fold. The research concluded pesticide applications in the agricultural fields affect not only the crops, but any nearby weeds and “non-crops” contaminated by drift on which bees may forage.
This is the first study to examine the effects of “real-world pollen-pesticide blends on honey bee health.” Beekeepers have been expressing concerns about fungicide impacts on their bees for years, and are pleased the research is being done.
The National Pollinator Defense Fund (NPDF) is appreciative of this research, and encourages additional research based on these findings. The NPDF agrees with the USDA and university researchers in advocating for “testing more broadly than the insecticides that are the targets of most current research;” for testing of sub-lethal effects of pesticides; working to understand the modes of action of pesticides; “looking at additive and synergistic effects between multiple pesticides;” examining the lethal and sub-lethal effects of fungicides on honey bees; and, researching the “pesticide-pesticide and pesticide-disease synergistic effects.”
This research is an important step in examining the effects upon the health of bees and other pollinators from the many, and varied pesticides used throughout agriculture. The real-world experiences of beekeepers and their bees should continue to be a focus of research efforts. As an indicator species, bee health is key to an affordable and sustainable food supply. Understanding how insecticides and fungicides interact, and impact honey bees is vital to maintaining healthy and vibrant agriculture.
NPDF Supports Oregon’s Review of Dinotefuran
The National Pollinator Defense Fund applauds the actions of the Oregon Dept. of Agriculture in their review of pesticides after bumble bees were killed from the use of Safari. This loss of native pollinators is not an isolated case; it was just a very public and highly visible incident. Thousands of dead bumble bees in a parking lot brought attention to the misuse of pesticides that happens throughout the U.S. in backyards, parks, farms, and cities. The loss of pollinators, managed and native, due to a misuse of pesticides is constant in farms and fields: the remains of the bees however, are not as physically visible across 400 acres, as they are in a paved parking lot.
The Oregon Dept. of Agriculture was correct in reviewing the use of this pesticide. If the product can be used safely, sparingly, and according to the label then it can be utilized per its purpose: protection from damaging pests. The key in the evaluation of this pesticide is “using the product per the label.” Sadly, a misuse of pesticides is caused by users not reading the label, as well as the label not clarifying the risks of the pesticide, especially if mixed with fungicides or herbicides. In this case the label clearly stated, “This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area.”
The National Pollinator Defense Fund supports the Oregon Dept. of Agriculture’s review of eighteen pesticides with the active ingredient dinotefuran in order to determine safe guidelines for use, that the product is used sparingly, is not applied to blooming plants, and is the last alternative to control a plant damaging pest.
Bees in the picture
Post your photos of pollinators on the FACEBOOK page of the National Pollinator Defense Fund. Look at blooming plants in your yard, or at commercial landscape displays, community garden, city park, and farm, and share with us your photos of pollinators from your community. Share with us how bees and other pollinators are working to help make your community beautiful.
MILES TO GO–Keeping Them Alive, Getting Them There and Back
A two day conference on every aspect of Migratory Beekeeping
Oct. 5-6, 2013
Presented by Bee Culture: The Magazine of American Beekeeping
If you move bees for a living, are going to or are thinking about it, you will not find the information, demonstrations and discussions offered at this gathering at any meeting, anywhere, ever.
To register, call Kim Flottum at 330-725-6677 ext. 3214 M – F 8 – 5, or email Kim@BeeCulture.com. With “Miles” in the subject line. Or call Amanda Shaffer at 330-725-6677 ext. 3255 T – F same hours. AShaffer@BeeCulture.com., same subject. Or, fill out the registration form that is attached and return it with a check made out to Bee Culture to the address listed on the form.