Grant: CCI Applied Research and Development Grants

The alfalfa leafcutting bee (Megachile rotundata Fab.) is the most intensively managed solitary bee in the world and is a vital pollinator of several valuable seed crops in North America. Each year, over 4 billion alfalfa leafcutting bees are responsible for pollinating alfalfa seed and hybrid canola seed fields in Canada and the USA. However, there is a critical lack of research on how the health, fitness, and pollination services of alfalfa leafcutting bees are affected by disease and pest pressures. In an era where the honey bee is failing to keep up with rapidly expanding pollinator-dependent cropland, it is imperative to invest in research focused on the sustainable management of other crop pollinators. Although there is limited evidence of inter-species transmission between crop pollinators, several honey bee viruses have been detected in leafcutting bees. However, the influence of pathogens on leafcutting bee reproduction and pollinator performance are poorly understood. Further research is required to understand how pathogens are transmitted among leafcutting bees and their influence on bee health and reproduction. There is also a pressing need to develop sustainable control options for existing pests of leafcutting bees. One of the most prevalent pests plaguing the industry is Pteromalus venustus, a small wasp that parasitizes leafcutting bees in the larval stage and causes serious bee mortality and economic loss. Research on Pterolmaus wasps has mostly focused on its use as a biocontrol insect for pests that damage stored seed products. Little is known on the ecology and mechanisms of control when the host insect is a valuable crop pollinator. Currently, leafcutting bee managers have very limited control options for P. venustus, due registered product restrictions and a limited understanding of this parasite and the modes of action of control products. Thus, the main objectives of our research is to improve leafcutting bee health, through an investigation of emerging and known pathogens and the development of sustainable and effective pest control options.