Abstract
1. The successful establishment of novel plant–insect interactions may depend on the availability of suitable hosts, which itself is influenced by the inherent flexibility of the herbivore for the native plants in its new range. The polyphagous beech leaf mining weevil, Orchestes fagi L., is a recent invader to eastern Canada, and while beech is a primary host, it remains unclear the extent to which it might also utilise co-occurring secondary hosts, as has been observed in its native European range. 2. A combination of field and laboratory feeding trials were used to quantify weevil secondary host use. Based on its expansive native host range in Europe, it was predicted that American beech (Fagus grandifolia Ehrh.), as well as several additional plant species, would be susceptible to weevil damage. 3. Contrary to this prediction, weevil feeding was almost entirely exclusive to beech in both the field and laboratory feeding trials. This result is further supported by field observations that revealed an absence of weevils and eggs on species other than beech. In general, the lack of pre-diapause feeding on any alternate host species represented an extreme departure from feeding habits observed within the native range. 4. Overall, this host-use bottleneck suggests that the adoption of a novel primary host by O. fagi, in this case American beech, may remove the normal requirement for secondary hosts and suggests a significant departure from native feeding habits with possible consequences for related life-history parameters such as overwintering survival and fecundity.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call