Country-specific effects of neonicotinoid pesticides on honey bees and wild bees

TLDR

Critics argued that earlier studies did not reflect field‑realistic pesticide levels or environmental conditions. Two studies on different crops and continents confirm that neonicotinoids reduce bee health, with exposure via nontarget pollen decreasing survival and immune responses near corn, and exposure from multiple sources reducing overwintering success and colony reproduction in honeybees and wild bees. Relevant studies are Tsvetkov et al.

Abstract

Damage confirmed Early studies of the impacts of neonicotinoid insecticides on insect pollinators indicated considerable harm. However, lingering criticism was that the studies did not represent field-realistic levels of the chemicals or prevailing environmental conditions. Two studies, conducted on different crops and on two continents, now substantiate that neonicotinoids diminish bee health (see the Perspective by Kerr). Tsvetkov et al. find that bees near corn crops are exposed to neonicotinoids for 3 to 4 months via nontarget pollen, resulting in decreased survival and immune responses, especially when coexposed to a commonly used agrochemical fungicide. Woodcock et al. , in a multicounty experiment on rapeseed in Europe, find that neonicotinoid exposure from several nontarget sources reduces overwintering success and colony reproduction in both honeybees and wild bees. These field results confirm that neonicotinoids negatively affect pollinator health under realistic agricultural conditions. Science , this issue p. 1395 , p. 1393 ; see also p. 1331