Beware of “Bee-Friendly” Plants

A pilot study conducted by Friends of the Earth-US and Pesticide Research Institute found that garden plants sold at top retailers contained neonicotinoid pesticides toxic to bees.

Findings include:

• Neonicotinoid residues were detected in seven out of thirteen samples (54 percent) of commercial nursery plants. In the samples with detections, concentrations raged from 11 to 1,500 micrograms per kilogram (ug/kg or parts per billion) of plant material.

• The percentage of contaminated plants and their neonicotinoid concentrations suggest that this problem is widespread, and that many home gardens have likely become a source of exposure for bees.

• For the samples with positive detections, adverse effects on bees and other pollinators are possible, ranging from sublethal effects on navigation, fertility, and immune function to bee death.

This pilot study points to the need for further studies in order to provide a statistical picture of the scope of nursery plant contamination with neonicotinoid insecticides. Larger sample sizes with sufficient plant material to directly measure pollen and nectar concentrations of neonicotinoids in plants treated with both foliar and soil applications would help to clarify some of the questions raised by this preliminary work. Additional studies that measure the distribution of neonicotinoid pesticides in different plant parts over time for different pesticides, plants and soil types are also necessary to enable prediction of pesticide concentations in pollen and nectar.

For more information, please visit the Friends of the Earth’s BeeAction campaign webpage.