Abstract
The majority of herbivorous insects are specialized in host use. Even among insects that use many hosts, local specialization is common with a single host plant often being used in any given locality. Here, we establish such a pattern for the European swallowtail butterfly, Papilio machaon. We sampled larvae on five different natural hosts at eight sites in Sweden, each locality showing local monophagy. We ask what is the underlying reason for this pattern, (1) local genetic adaptation with each population being genetically adapted to the local host, (2) Hopkins' host selection principle with adult females retaining a memory of the larval host and preferring to oviposit on that plant, or (3) the preference/performance hypothesis which posits that females should oviposit on the local plant(s) on which larval fitness is highest. Allozyme analysis supported a relatively low level of population structuring, and oviposition preference tests showed that females from all sites had similar preference rankings of the five host plants. Hence, there was no support for local genetic adaptation or Hopkins' host selection principle. Instead, the results are consistent with the preference/performance hypothesis with local monophagy probably being implemented by a preference ranking of plants in accordance with larval performance. (Less)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.