The potential for parasite spill-back from commercial bumblebee colonies: a neglected threat to wild bees?

Unlabelled: Commercially-reared bumblebee colonies provide pollination services to numerous crop species globally. These colonies may harbour parasites which can spill-over to wild bee species. However, the potential for parasites to spread from wild to commercial bumblebees, which could then lead to parasite spill-back, is poorly understood.

Agrochemicals interact synergistically to increase bee mortality.

Global concern over widely documented declines in pollinators has led to the identification of anthropogenic stressors that, individually, are detrimental to bee populations. Synergistic interactions between these stressors could substantially amplify the environmental effect of these stressors and could therefore have important implications for policy decisions that aim to improve the health of pollinators. Here, to quantitatively assess the scale of this threat, we conducted a meta-analysis of 356 interaction effect sizes from 90 studies in which bees were exposed to combinations of agrochemicals, nutritional stressors and/or parasites.

Varietal and seasonal differences in the effects of commercial bumblebees on fruit quality in strawberry crops.

Both wild and managed pollinators significantly contribute to global food production by providing pollination services to crops. Colonies of commercially-reared honey bees and bumblebees are two of the largest groups of managed pollinators. Bumblebees in particular are increasingly used on soft fruit crops, such as strawberry, an economically important crop globally.

Bumblebee olfactory learning affected by task allocation but not by a trypanosome parasite.

Parasites can induce behavioural changes in their host organisms. Several parasite species are known to infect bumblebees, an important group of pollinators. Task allocation within bumblebee colonies can also cause differences in behaviour.

The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project.

The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.

Global effects of land use on local terrestrial biodiversity.

Human activities, especially conversion and degradation of habitats, are causing global biodiversity declines. How local ecological assemblages are responding is less clear--a concern given their importance for many ecosystem functions and services. We analysed a terrestrial assemblage database of unprecedented geographic and taxonomic coverage to quantify local biodiversity responses to land use and related changes.