Molecular phylogenetics of Neotropical chrysomeline beetles: Evidence for a constrained history of host plant use

AO_SCPLOWBSTRACTC_SCPLOWThis study reconstructs the phylogeny of an expansive set of Neotropical leaf beetles in the subfamily Chrysomelinae. From 33 species in the genus Platyphora Gistel, and an additional 37 species representing 16 beetle genera, five genes, three nuclear, and two mitochondrial, were sequenced and used to obtain a well-supported molecular phylogeny using both Bayesian and Maximum Likelihood. The subtribes Chrysomelina and Doryphorina (sensu Daccordi 1982) were monophyletic, while the genus Platyphora was polyphyletic. The genus Leptinotarsa Chevrolat is confirmed to be distinct from Stilodes Chevrolat. Host plant family was recorded for both adults and larvae using direct observations where possible. Ancestral host plant use was reconstructed using Bayesian trait analyses. A complicated history of host plant switches among a restricted set of plant families is revealed: In the paraphyletic Platyphora, one clade that includes Proseicela and Leptinotarsa had two switches from Asclepiadiodeae to Solanaceae, one switch to Moraceae, and one switch to Malpighiaceae, another Platyphora clade had switches between Asteraceae and Rauvolfioideae, and from Rauvolfioideae to Asclepiadiodeae, with other members of the same clade feeding on Boraginaceae and Convolvulaceae. All species included in the clade containing Tritaenia and Stilodes fed on Malpighiaceae, and all species included in the Cosmogramma and Calligrapha clade fed on Malvaceae.