Molecular phylogeny reveals food plasticity in the evolution of true ladybird beetles
The tribe Coccinellini is a group of relatively large ladybird beetles that exhibits remarkable morphological and biological diversity. Many species are aphidophagous, feeding as larvae and adults on aphids, but some species also feed on other hemipterous insects (i.e., heteropterans, psyllids, and whiteflies), beetle and moth larvae, pollen, fungal spores, and even plant tissue. Several species are biological control agents or widespread invasive species. Despite the ecological importance of this tribe, relatively little is known about the phylogenetic relationships within it.
Oldřich Nedvěd at the Department of Zoology, Faculty of Science and the Biology Center of the Academy of Sciences of the Czech Republic has become a member of the international scientific team that has produced the most complete phylogenetic analysis of the Coccinellini tribe to date. In their analysis, based on three nuclear and one mitochondrial genes, they included a total of 38 ladybird species representing all major groups. From the phylogenetic analysis, they inferred which characters of these ladybirds are ancestral, and which originated later in the evolutionary history of the tribe Coccinellini.
The results of the phylogenetic analysis show that the earliest members of the tribe were predators, feeding on aphids. The predatory way of life seems to make it easy for ladybirds to specialize on a different diet, in extreme cases, to eat mushrooms or plants. Adult ladybirds that feed on aphids can survive unfavorable periods by eating pollen or nectar from plant flowers. Scientists also found that the original taxonomic classification of true ladybirds was heavily influenced by the morphological similarity of species that are not, in fact, closely related.
Escalona, H. E., Zwick, A., Li, H. S., Li, J., Wang, X., Pang, H.,Hartley, D., Jermiin, L.S., Nedvěd, O., Misof, B., Niehuis, O., Ślipiński, A., & Tomaszewska, W. (2017). Molecular phylogeny reveals food plasticity in the evolution of true ladybird beetles (Coleoptera: Coccinellidae: Coccinellini). BMC Evolutionary Biology, 17(1), 151. https://bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-017-1002-3