Correlated evolution of biology and morphology of related organs of insects is an intriguing yet poorly understood topic. Gigantic member of phytophagan, the subfamily Cerambycinae provide us a unique opportunity to understand the topic because they have wide range of host plants, oviposition strategies and various forms of ovipositors. The evolutionary pathway of these traits is totally unknown because no robust internal phylogeny has been studied. Here we construct a multilocus phylogeny of Cerambycinae (134 taxa, 9 gene regions, 5211bp) focusing on wide range of oviposition strategies, host plant and ovipositor length. Ancestral state reconstruction analyses show that shortened ovipositor in Cerambycinae evolved at least four times independently; host plant use evolved from stressed hosts to dead and living host, broad leaved trees to conifer and herbaceus plants. Continuous mapping of ancestral state reconstruction shows extremely shortened ovipositor evolved independently at least four times. The correlated evolution test revealed the only correlation is between the ovipositor length and the oviposition strategy. This study unveiled the complex evolutionary history of ovipositor, oviposition strategy, host plant usage and their correlation within Cerambycinae for the first time.

Evolutionary relationship between ovipositior and oviposition behaviour in insect is an intriguing yet poorly understood topic. Gigantic member of phytophagan, the subfamily Cerambycinae provide us a unique opportunity to understand the topic because they have diversified but specialized host plants, oviposition strategies and ovipositors. The evolutionary pathway of these traits is totally unknown because no robust internal phylogeny of Cerambycinae has been studied. Here we construct a multi-locus phylogeny of Cerambycinae (134 taxa, 9 gene regions, 5211bp) focusing on wide range of oviposition site, host plant and ovipositor length. Ancestral state reconstruction analyses show some general trends in cerambycine evolution: i) host plant use evolved from stressed broad leaved trees to conifers and herbaceus plants; ii) oviposition site evolved from bark crevice to wood fissure or plant surface; iii) extremely shortened and elongated ovipositor independently evolved at least four times, respectively. Correlated evolution test show that ovipositor length and oviposition strategy evolved with very strong correlation, while any of other two traits did. This study unveils the complex evolutionary history of ovipositor, oviposition site, host plant use and their correlation within Cerambycinae for the first time.