Pollinators: Threats to Pollinators

Biology

Pollinators are threatened by a multitude of factors including habitat degradation and fragmentation, decline of flower-rich plant communities, the spread of pathogens, pesticide use and climate change. Of these threats, habitat degradation and pesticide use are probably the most damaging to pollinator communities. Conversion of natural habitats into extensive agricultural enterprises and residential/commercial development is the prime cause for the serious declines in pollinator populations currently occurring worldwide. The ongoing and increased use of pesticides in agricultural and urban areas has both direct and indirect effects on pollinators. Insecticides often have a direct killing effect on pollinators but even when not directly toxic can still suppress populations by having chronic deleterious effects on population parameters like development, reproduction and movement. For example, neonicotinoid insecticides although reasonably safe to vertebrates, can reduce longevity, egg production, foraging efficiency and overall viability of pollinators, even when not directly exposed. Evidence is mounting that small but biologically significant concentrations of neonicotinoids accumulate in flower nectar and pollen, routinely exposing pollinators to these mobile and long-lived insecticides.