A 3-Year Study of the Impact of Imidacloprid-Treated Hardwoods on Pollinator Health in Worchester County, Massachusetts
2012 Annual Report
1a.Objectives (from AD-416):
Determine the expression rates in nectar and pollen of imidacloprid in three tree species and the potential impacts of pesticide residues on pollinators.
1b.Approach (from AD-416):
APHIS is proposing to treat multiple species of hardwoods located in and around Worcester County, Massachusetts, with imidacloprid (IMI) to help eradicate the invasive Asian longhorned beetle (ALB). The treatment of these trees (by injection and soil application) should result in translocation of IMI throughout the tree and could result in the potential expression of IMI in nectar and pollen. USDA-ARS is proposing to monitor the movement of IMI to pollen and nectar and evaluate the potential effects on honeybees and other non-target species over a three year period.
In FY12, the movement of the neonicotinoid insecticide imidacloprid was monitored in hardwood trees in New York and Massachusetts, as part of the Asian Longhorned Beetle control program. Leaf, pollen and bee samples were collected from 16 sites in NY and 8 sites in MA to monitor for the movement of imidacloprid in hardwood trees. Exposure levels to bees were documented in pollen in the NY study and three years of data are being prepared for publication on exposure routes in hardwood trees. The pesticide levels seen in pollen in NY were well below the threshold thought to have effects on adult honey bees. Leaves held the highest concentrations of the pesticide, followed by whole flowers; and finally pollen had detectable but low levels. Colony level exposure and or impacts will continue to be monitored in MA for 2 more years while the three-year study in NY has been completed.