Bee flower choices altered by exposure to pesticides

http://www.eurekalert.org/pub_releases/2016-03/uog-bfc031116.php

Public Release: 14-Mar-2016
Bee flower choices altered by exposure to pesticides
University of Guelph

Low levels of pesticides can impact the foraging behaviour of bumblebees on wildflowers, changing their floral preferences and hindering their ability to learn the skills needed to extract nectar and pollen, according to a study co-authored by a University of Guelph professor.

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Bees and other insects pollinate many of the world's important food crops and wild plants, raising serious concerns about the impacts of reported global pollinator declines for food security and biodiversity.

The researchers found that bumblebees exposed to a realistic level of a neonicotinoid insecticide (thiamethoxam) collected more pollen but took longer to do so than control bees. Pesticide-exposed bees also chose to forage from different flowers than control bees.

"Bees rely on learning to locate flowers, track their profitability and work out how best to efficiently extract nectar and pollen," said environmental sciences professor Nigel Raine, the Rebanks Family Chair in Pollinator Conservation at U of G and senior author of the paper.

"If exposure to low levels of pesticide affects their ability to learn, bees may struggle to collect food and impair the essential pollination services they provide to both crops and wild plants."

Previous studies have found that exposure to neonicotinoid pesticides can cause changes in the brain, more specifically in the areas associated with learning and memory in honeybees.

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