Mitigating Pollinator Decline in Minnesota

PROJECT OVERVIEW
A class of insecticides known as systemic neonicotinyl insecticides have been identified as a potential factor in recently observed declines in pollinators - the beneficial insects that carry pollen from plant to plant - including the phenomenon amongst honeybees known as Colony Collapse Disorder. But only preliminary investigation into this potential link has been completed to date. This appropriation is enabling the University of Minnesota's Department of Entomology to conduct additional research needed to determine what impacts systemic neonicotinyl insecticides may be having on the health, behavior, and mortality of honeybees and other pollinators. Findings could be used to help mitigate pollinator decline and identify alternative approaches for managing pest insects.

OVERALL PROJECT OUTCOME AND RESULTS
The commonly used systemic neonicotinyl class of insecticides (imidacloprid, thiamethoxam, clothianidin, and dinotefuran) is implicated in bee decline since insecticide residues accumulate in pollen and nectar. These residues can kill foraging bees and decrease pollination, seeds, and fruits of native plants and crops.

Neonicotinyls are applied in numerous methods (seeds, soil drenches, and tree trunk injections). Of the 442 million acres of U.S. cropland, 143 acres are treated with over 2 million pounds of neonicotinyl insecticides. In Minnesota in 2009, 46,766 pounds of imidacloprid and 19,347 pounds of clothianidin were applied.

These research objectives were to understand the effects of imidacloprid residues on bee health. This research found that a standard, label rate of imidacloprid applied to soil of potted plants produced imidacloprid residues of 1973 ppb in mint and 1568 ppb in milkweed flowers. A residue in flowers of 185 ppb imidacloprid kills a bee.

Research on greenhouse colonies of bumblebees showed that 20-100 ppb imidacloprid or clothianidin provided in sugar syrup for 11 weeks increased queen mortality and decreased consumption, sugar syrup storage, colony weight, and male production. Consequently, 20 ppb had detrimental effects on bumblebees and will reduce pollination of native plants. Research on field colonies of honey bees showed that only 33% of the imidacloprid was stored in colony cells. At 200 ppb there was less brood, fewer returning foragers, and higher amounts of distorted wing virus, which can cause colony death.

This research demonstrated that applications of imidacloprid and clothianidin insecticides to soil result in high residues in nectar and pollen that will kill bees. Studies on bees showed how colonies died from these insecticides.

An 11 part website for outreach education in Minnesota on pollinator conservation was developed.

PROJECT RESULTS USE AND DISSEMINATION
The purpose of the research was to supply data to protect pollinators to ensure future seeds and fruits for wildlife and people. These research data are very important to groups trying to understand the impact of systemic, neonicotinyl insecticides on bee colonies and individual foragers. These data are used by bee keepers, advocacy groups, state agencies, and the US EPA for discussion on whether neonicotinyl insecticides are affecting bee health and whether their use needs to be restricted. In June 2013 The European Union's Food Safety Authority (EFSA) has restricted the use of neonicotinyl insecticides for 2 years on all flowering plants that bees utilize. The reports and discussion are on the LCCMR sponsored "Pollinator Conservation" website. This is a remarkable proactive decision to ensure the safety of pollinators.

An 11 part website on bee pollinator conservation was developed for outreach education in Minnesota. The website contains research results, manuscripts, workshop, bulletin on insecticides and bees, bulletin on pollinator conservation, and poster on bee plants. We will produce 4 manuscripts from these data and 3 are already in final form and available on the website.

These research data have been requested by groups that need to understand more about the risk of neonicotinyl insecticides to bees: US EPA, Center for Food Safety, PANNA (Pesticide Action Network), Xerces Society for Invertebrate Conservation, Washington State Department of Agriculture, Pesticide Research Institute, MN Honey Producers, Boulder County Bee Keepers, and Colorado State Beekeepers. The lab was interviewed by TV and radio many times: MN Public Radio (3), Harvest Public Media, Iowa Public Radio, WCCO, Kare 11 News, KSTP, Pioneer Press, Star Tribune, and the Minnesota State Fair. Krischik has provided her research results to the US EPA twice: an online slide show webinar to EPA scientists and a visit to UM by the US EPA Administrator for the Office of Chemical Safety and Pollution Prevention (OCSPP). Krischik's expertise from this research has made her a reviewer for 2 white papers from the Xerces Society of Invertebrate Conservation and another from the Friends of the Earth as well as peer reviewer on related scientific manuscripts.