Research objectives and content
Importance of secondary compounds as chemical defences against herbivores is widely admitted. However less is known out the mechanisms of this anti-herbivore activity. The aim of this project is studying behavioural consequences of secondary compounds on insect herbivores and its natural enemies. We will do it by using interactions between mountain birch (Betula pubesencs) and its herbivores, a well-known system in Subartic area. The most innovative points of this proposal are related to the use of crude extracts and individual purified compounds in order to compare roles of different molecules against herbivores. The proposed experiments will also elucidate questions of evolution of herbivore resistance in mountain birch at intra-specific level. Evolution of herbivory interactions by natural selection required the existence of variation at this level. Variation between plant individuals on composition of secondary compounds has been proved for mountain birch, and there are hints that this variation has a genetic basis. However, the question of resistance is further complicated by the possibility that behavioural responses of individual herbivore species, the subject of the proposal.
Training content (objective, benefit and expected impact)
Results of behavioural tests will indicate which of the natural components of leaf composition are effective to deter/attract, disperse and/or increased defoliation in mountain birches. This will contribute to elucidate the role of plant secondary compounds in determining the actual level of damage to individual trees -both via toxicity of the compounds and deterrence- an incompletely known question in spite of its obvious theoretical and practical importance.
Links with industry / industrial relevance (22)