Mixture of neonicotinoid and fungicide affects foraging activity of honeybees.

The use of plant protection products (PPPs) is a major factor contributing to global insect decline. We here use the honeybee (Apis mellifera) as a model to study combined effects of the last neonicotinoid in the EU (acetamiprid) and different fungicides on live-long foraging flights using radio frequency identification. The mixture of the sterol-biosynthesis-inhibiting fungicide difenoconazole and the insecticide acetamiprid significantly reduced the number of foraging trips per day compared to the control and each PPP alone, while a mixture of the insecticide with the non-sterol-biosynthesis inhibiting fungicide boscalid/dimoxystrobin did not affect behaviour.

The neonicotinoid acetamiprid reduces larval and adult survival in honeybees (Apis mellifera) and interacts with a fungicide mixture.

Plant protection products (PPPs), which are frequently used in agriculture, can be major stressors for honeybees. They have been found abundantly in the beehive, particularly in pollen. Few studies have analysed effects on honeybee larvae, and little is known about effects of insecticide-fungicide-mixtures, although this is a highly realistic exposure scenario.

Bumblebees are resilient to neonicotinoid-fungicide combinations.

Bumblebees are among the most important wild bees for pollination of crops and securing wildflower diversity. However, their abundance and diversity have been on a steady decrease in the last decades. One of the most important factors leading to their decline is the frequent use of plant protection products (PPPs) in agriculture, which spread into forests and natural reserves.