Shape-dependent leaf manipulation in the leaf rolling weevil Phymatapoderus pavens (Coleoptera: Attelabidae)

Abstract

Abstract Plant leaves are utilized by various shelter-building insects. Some insects are constrained in their host plant use by the difficulty in modifying leaves into shelters, while others may cope through different construction methods. Here, we show that the leaf-rolling weevil Phymatapoderus pavens (Coleoptera, Attelabidae) constructs two types of leaf rolⅼ on Boehmeria silvestrii (Urticaceae) according to the shape of the leaf. Female weevils make leaf rolls using the whole leaf when the leaf is small and weakly lobed, whereas they use only one of the lateral lobes when the leaf is large and deeply lobed. Both types were found within a population and each functioned as a site for the growth of offspring. Weevils bite the leaf veins differently when constructing each of these leaf rolls, suggesting that the leaf roll type is determined before the leaf is rolled. Compared with another leaf-rolling weevil species, Apoderus praecellens (Coleoptera, Attelabidae), which makes leaf rolls on similarly lobed leaves of Isodon umbrosus var. hakusanensis (Lamiaceae), P. pavens utilizes a wider range of leaf shapes because these weevils are able to construct leaf rolls on the lateral lobes of the leaves. Differences in leaf-rolling behaviour, leaf venation pattern, and the relative size of weevils and leaves are factors affecting the results.