Testing for congruence between the oviposition behaviour of leaf-mining insects and the degree of phylogenetic relatedness among either mining species or hosts species: a case study within the mining moth genus Phyllonorycter (Lepidoptera: Gracillariidae)

In leaf-mining insects, the oviposition behaviour is especially critical for the welfare of the future brood, the latter being usually doomed to develop entirely within the host-leaf selected for egg-laying by the ovipositing females. As, moreover, oviposition behaviour in leaf miners depends upon the taxonomic identities of both the mining-insect and the host, one can thus speculate that the patterns of oviposition behaviour of different leaf-mining species could be more or less congruent with either the degree of phylogenetic relatedness of the leaf-mining species themselves or the degree of phylogenetic relatedness of their respective host-species. Here, I test successively these two hypotheses – the “miners phylogenetic relatedness” hypothesis and the “hosts phylogenetic relatedness” hypothesis – by addressing a system insect-plant involving four mining moth species (all four belonging to the genus Phyllonorycter) and the three corresponding host-tree species, all included within the family Betulaceae. It turns out that, for this system at least, neither of the two previous hypotheses is actually supported. Possible reasons for this double rejection are discussed accordingly.