Abstract
BackgroundThe 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, whiteflies), beetle and moth larvae, pollen, fungal spores, and even plant tissue. Several species are biological control agents or widespread invasive species (e.g., Harmonia axyridis (Pallas)). Despite the ecological importance of this tribe, relatively little is known about the phylogenetic relationships within it. The generic concepts within the tribe Coccinellini are unstable and do not reflect a natural classification, being largely based on regional revisions. This impedes the phylogenetic study of important traits of Coccinellidae at a global scale (e.g. the evolution of food preferences and biogeography).ResultsWe present the most comprehensive phylogenetic analysis of Coccinellini to date, based on three nuclear and one mitochondrial gene sequences of 38 taxa, which represent all major Coccinellini lineages. The phylogenetic reconstruction supports the monophyly of Coccinellini and its sister group relationship to Chilocorini. Within Coccinellini, three major clades were recovered that do not correspond to any previously recognised divisions, questioning the traditional differentiation between Halyziini, Discotomini, Tytthaspidini, and Singhikaliini. Ancestral state reconstructions of food preferences and morphological characters support the idea of aphidophagy being the ancestral state in Coccinellini. This indicates a transition from putative obligate scale feeders, as seen in the closely related Chilocorini, to more agile general predators.ConclusionsOur results suggest that the classification of Coccinellini has been misled by convergence in morphological traits. The evolutionary history of Coccinellini has been very dynamic in respect to changes in host preferences, involving multiple independent host switches from different insect orders to fungal spores and plants tissues. General predation on ephemeral aphids might have created an opportunity to easily adapt to mixed or specialised diets (e.g. obligate mycophagy, herbivory, predation on various hemipteroids or larvae of leaf beetles (Chrysomelidae)). The generally long-lived adults of Coccinellini can consume pollen and floral nectars, thereby surviving periods of low prey frequency. This capacity might have played a central role in the diversification history of Coccinellini.
Highlights
The tribe Coccinellini is a group of relatively large ladybird beetles that exhibits remarkable morphological and biological diversity
Phylogenetic analyses The ML and Bayesian phylogenetic analyses of the fivefragment multiple sequence alignments (MSAs) resulted in identical topologies (Fig. 3, ML topology, log likelihood −55,518.302879 and Additional file 7: Fig. S2, the result from the Bayesian analysis)
The ML analysis of the degeneracy-coded five-fragment MSA resulted in a similar topology with 21 of 49 edges at least moderately supported (Additional file 8: Fig. S3)
Summary
The tribe Coccinellini is a group of relatively large ladybird beetles that exhibits remarkable morphological and biological diversity. The generic concepts within the tribe Coccinellini are unstable and do not reflect a natural classification, being largely based on regional revisions This impedes the phylogenetic study of important traits of Coccinellidae at a global scale (e.g. the evolution of food preferences and biogeography). Most of the traditional classifications of Coccinellidae [8,9,10] recognize six or seven subfamilies (i.e., Chilocorinae, Coccidulinae, Coccinellinae, Epilachninae, Scymninae, Sticholotidinae, and sometimes Ortaliinae, each with numerous tribes) The foundation of this system was developed by Sasaji [11, 12] based on comparative morphological analyses of adults and larvae from species of the Palaearctic Region, mostly Japan. Based on results of phylogenetic analyses of molecular data and a combination of molecular and morphological data from Coccinellidae, Ślipiński and Tomaszewska [18] and Seago et al [17] formalized the taxonomic status of Coccinellini as a tribe within the broadly defined Coccinellinae
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
