In a joint report released by USDA and the U.S. Environmental Protection Agency last week, several possible causes of the national decline in honeybees were outlined, including habitat loss, poor diet, diseases, parasites and pesticide exposure. Research so far points to a combination of these factors that may be responsible for the 30% decline in honeybees annually since 2006.
Bees through their role in pollination are considered to be directly or indirectly responsible for about every third bite of food we eat, according to USDA. Crops that are predominantly pollinated by honeybees have an estimated value of more than $215 billion annually worldwide.
Matt O'Neal, an ISU associate professor of entomology, and Erin Hodgson, assistant professor and ISU Extension entomologist, say seed treatment insecticides are used to protect the germinating seed from pests. By taking some precautions, farmers can help minimize bee exposure to these insecticides.
Farmers can take some steps to help minimize bee exposure to these insecticides
The ISU entomologists advise farmers to clean the seed treatment residues from planting equipment away from fields and minimize the off-site dust movement from treated seeds. By taking these precautions, farmers could help minimize bee exposure to a class of insecticides, called neonicotinoids, which some studies have identified as a particular concern.
Using the recommended rate of lubricants that aid the flow of seed through planters is another way to minimize exposure to bees, as well as being aware of wind speed and direction around flowering plants when applying pesticides, say the ISU entomologists.
Alerting local beekeepers of upcoming pesticide applications is an important practice. The Iowa Department of Agriculture and Land Stewardship maintains an Iowa Sensitive Crops Directory that includes the locations of hives.
Alerting local beekeepers before you make pesticide applications, and growing perennial plants around edges of fields, are two other steps you can take
O'Neal says farmers can encourage bee populations by growing native perennial plants around agricultural fields to improve foraging habitat. He includes specific recommendations in a recent ISU publication by the Leopold Center for Sustainable Agriculture.~~~PAGE_BREAK_HERE~~~
Hodgson and O'Neal have written an article about bee health recommendations, and that article appears in the ISU Integrated Crop Management Newsletter.
European Union announces restriction on use of neonicotinoid insecticides
In addition to the USDA/EPA report on the health of honeybees in the United States, another item in the news recently has been the announcement by the European Union regarding the EU's restriction on the use of neonicotinoid insecticides.
"These events share a similar theme of preventing a widespread decline in pollinator abundance," says Matt O'Neal. What do these events mean for the on-going efforts to conserve pollinators and for the future of insecticide product registration in the United States? O'Neal and ISU colleague Erin Hodgson offer the following perspective.
* Neonicotinoid insecticides banned in Europe. On April 29, 2013, the EU voted to restrict the use of neonicotinoid insecticides (specifically clothianidin, imidacloprid and thiamethoxam) beginning December 2013. Globally, these insecticides are used in a variety of agricultural and landscape settings, including the production of field crops, fruits, vegetables and home gardens. Many neonicotinoids are systemic, capable of moving through the plant. Because they are used to combat a wide variety of pests, there is the risk that non-target insects, like pollinators, can be exposed to them.
As noted by scientists in the EU, it is not clear the extent to which the widespread use of neonicotinoids is responsible for declines in pollinator health, abundance and diversity. As many news agencies have reported, the goal of this two-year restriction is to allow time for additional studies and data to be assessed, while potentially allowing for improvements in pollinator abundance.
* What does this mean for U.S. farmers? While these two events—the EU restriction on the use of neonicotinoiods and the USDA/EPA report— share a similar theme, there are also some differences. One is that the EU ruling is addressing a decline in all pollinators, not just honey- bees, notes O'Neal. Although honeybees are currently the most important pollinator of crops, many other species are used. Second, the EU is focused on restricting neonicotinoids, while the EPA report on Colony Collapse Disorder had an emphasis on all pesticides and other possible contributing factors.~~~PAGE_BREAK_HERE~~~
As more is learned about the impact of any insecticide on honeybees, and potentially pollinators in general, there may be future restrictions to how neonicotinoids, or any pesticide, can be used in the U.S. Every pesticide has to go through a regular, ongoing registration process with the EPA. Neonicotinoids are under close scrutiny by the public, and the upcoming labeled use could change to protect pollinators.
* Best management practices for landowners. Although there are many factors that can negatively affect pollinators (specifically honeybees), there are some practices that landowners can adopt to help conserve them. Here's a summary of the ISU entomologists' recommendations:
* Diversify the landscape around agricultural areas to improve foraging habitat. Include a variety of perennial, flowering plants. This could be native plants commonly found in Iowa prairies.
* Use the recommended rate of seed lubricant for proper planting.
* Be aware of wind speed and direction, especially near flowering plants.
* Do not clean plant equipment/hoppers near fields.
* Minimize off-site dust movement from treated seeds.
* Alert local beekeepers of upcoming foliar pesticide applications using the Sensitive Crops directory. This directory is provided by the Iowa Department of Agriculture.
* Target pesticide applications to minimize exposure by reducing drift potential and only applying products when necessary.
* Avoid spraying during daylight, especially morning hours. Bees visit flowers during the day. Spraying at dusk can reduce the potential of exposure.