Marrone Bio Innovations, Inc. (MBI), has received EPA approval to delete the bee toxicity warning statement from its Grandevo Bioinsecticide label following a review. The removal of the toxicity statement is supported by third-party field evaluations that show Grandevo has no increased mortality or detrimental effects to honeybees.
The study was conducted in central North Carolina during the summer of 2012. The month-long hive study compared the mortality rates of Grandevo versus a known toxic pesticide reference treatment and a water treatment control.
Grandevo, a cross-spectrum bioinsecticide, is shown to be effective in controlling chewing and sucking insects, as well as mites. It works through oral toxicity, reduced reproduction, and repellency. While tested extensively to understand its effects on non-target organisms, including lab studies with bees, prior to its EPA registration in 2012, Grandevo was not required to be field tested with honeybees.
“With the growing concern about the hazards many insecticides pose to bees and bee colonies, it was extremely important to do this field study. We can now reassure growers that Grandevo will not harm honeybees and can provide critically needed pest control throughout the growing season, including when bees are active,” Dr. Tim Johnson, global head of product development with MBI, explains.
The study began with Grandevo being applied on buckwheat pre-bloom and seven days later at full bloom during bee flight. The Grandevo maximum label rate of three pounds per acre was applied. Bee mortality was not statistically different between the water treatment control group (30 bees per colony) and the Grandevo-treated group (24.1 bees/colony) measured seven days after the initial application of Grandevo. At the same time, the known toxic pesticide treatment mortality rate was 1,808 bees per colony.
Marrone Bio Innovations is currently updating Grandevo state registrations with the revised environmental hazards statement.
For more information on the Grandevo field trial in North Carolina, visit the Marrone Bio Innovations website.