The organization of individual organisms into societies is one of the major transitions in evolution. Within social insects it has resulted in division of labour among casts and in construction of elaborate nests. In some insect groups some species have lost or never evolved the ability to build nests and instead invade and parasitize on the nests constructed by other species (hosts). In some systems the hosts are killed and in other they are manipulated to become slaves. As in many other insect-insect interactions, chemical signals are known or can be assumed to play an important role for the ability of the parasite to invade the host. The invading individuals avoid attacks by either being odour-free or by chemical mimicry.
This project aims to reveal what chemical cues are involved in the evolution of nest parasitism and defence. The goal is to achieve an integrated, interdisciplinary understanding of the chemical, physiological and evolutionary principles that have shaped chemical communication across insect societies of different evolutionary and ecological history. In particular, we will focus on adaptations and interactions in host-parasite systems within gall-inducing thrips, a group of relatively recent evolutionary origin. This will enable us to generalise about importance of chemical communication in the evolution of such systems.
Our model system consists of the host trees (Acacia spp.), the gall inducers (Kladothrips spp.) and their kleptoparasites (Koptothrips spp.), living in the dry outback of Australia.
Picture: Australian outback with Acacia trees. Photo: Olle Anderbrant.
Picture: Kladothrips intermedius with anal droplet. Photo: Monica De Facci
Eric Hallberg and Rita Wallén (Lund University)
Swedish Research Council (VR) 2007-2011
Kungl. Fysiografiska Sällskapet (2008, 2010)