What are some routes through which bees can be exposed to pesticides?

Bees can be exposed to pesticides primarily through runoff and pollen. When pesticides are applied to agricultural fields, they can be washed into nearby environments through water runoff, particularly during rain events. This runoff can carry residues that can affect bees if they venture into those areas. Furthermore, many plants also absorb these pesticides and then produce pollen containing pesticide residues. Bees foraging for nectar and pollen from contaminated plants are directly exposed to these harmful chemicals, which can adversely affect their health and the overall ecosystem.

Soil absorption and evaporation also play roles in pesticide dynamics, but they do not directly expose bees to pesticides in the same manner. Soil absorption relates more to the lasting residues of chemicals in the soil itself, and while it can have secondary effects, it does not provide a direct route of exposure for bees. Similarly, evaporation might influence the dispersion of volatile pesticides but does not translate into a significant pathway for bee exposure compared to runoff and contaminated pollen. Thus, focusing on the impact of runoff and pollen gives a clearer understanding of how pesticide exposure occurs in bee populations.