Grant: Strategic Projects - Group

Forests are an enormous economic resource in Canada and France. Not only do they represent an immediately exploitable resource, they are renewable and sustainable. Today we find our forests under the unprecedented twin threats of climate change and species invasions due to large-scale movement of people and products across the planet. Our project focuses on extensive insect invasions due to the global seed trade. Insect seed parasites destroy conifer seed crops and are essentially invisible within seed lots shipped internationally. Parasites also serve as vectors for pathogens, as well as facilitating the establishment of other pests. Our ability to predict the influence of insects and diseases on future landscapes depends on how well we understand the relationship between immobile trees and highly mobile insects. Tree seed insects damage forests and plantations in Canada and France, affecting native species of plants as well as the animals that depend on them. The success of seed insects is due to their ability to bypass barriers in the developing plant ovule. If we wish to manage seed insects, we need to know how the insect parasite hijacks its seed host, then moves through a species into other ones, and finally, how it then moves across a landscape. To tackle these international problems caused by global seed exchange we have assembled a team of Franco-Canadian experts in Megastigmus-conifer seed interactions including those specialized in plant and animal reproduction, forest pest surveys, entomology and modeling. We will focus on chalcid wasps in the genus Megastigmus (Hymenoptera; Torymidae), which are highly invasive and damaging species. M. spermotrophus is found on Douglas-fir. We will use transcriptomic and next-generation sequencing approaches to unveil mechanisms of control of the plant by the insect. We will characterize the microbes associated with Megastigmus, e.g. symbionts and potential pathogens. We will study insect and tree phenologies to decipher how diverse Megastigmus species are able to infest a broad range of tree species. This information, coupled with in-depth study of phylogenetic relationships of the chalcids, will be used to develop models of future invasion.