Pesticides are one of the main reasons for pollinator decline. A recent study in Finland was designed to establish the pesticide exposure of honeybees under field-realistic conditions, when pesticides were used according to EU legislation.
Experiments were conducted in turnip rape, oilseed rape, and caraway fields in southern Finland during 2019 and 2020. The pesticides used contained the active substances lambda-cyhalothrin (2019), esfenvalerate (2020), and tau-fluvalinate (2020). The researchers collected pollen using pollen traps in the hives before the first and immediately after every pesticide treatment, and collected nectar from the honey after pesticide treatment in 2020.
The researchers tested the honeybee-collected nectar and pollen for over 100 pesticides, and found pesticide levels below the oral acute toxicity for honeybees. They conclude that EU Regulation protected the honeybees from acute lethal doses during the study period, although stated that sublethal effects on colony survival and development could not be ruled out.
The researchers recommend constant monitoring of pesticide exposure of honeybees and wild pollinators to ensure that pesticide legislation and implementation successfully protects pollinators.
Read the full paper:
Kaila, L., Ketola, J., Toivonen, M., Loukola, O., Hakala,K., Raiskio, S., Hurme T. & Jalli, M. (2022) Pesticide residues in honeybee-collected pollen: does the EU regulation protect honeybees from pesticides? Environmental Science and Pollution Research 29, 18225–18244. https://doi.org/10.1007/s11356-021-16947-z