Molecular phylogeny and evolutionary habitat transition of the flower bugs (Heteroptera: Anthocoridae).

We performed a molecular phylogenetic study of the Anthocoridae, the flower bugs, based on maximum likelihood, maximum parsimony, and Bayesian analyses of ∼ 3000 base pairs (bp) of DNA sequence from the mitochondrial 16S rRNA and nuclear 18S rRNA and 28S rRNA genes for 44 taxa. Our phylogenetic analyses indicates that (i) the tribe Cardiastethini (Dufouriellini) could be a paraphyletic group, as the genera Amphiareus and Dysepicritus are not included in the tribe; (ii) the main subgroups, Oriini and Anthocorini, are monophyletic within Anthocoridae; (iii) three tribes of Blaptostethini, Xylocorini, and Scolopini are separated from the main anthocorid clade which is composed of Anthocorini, Cardiastethini, and Oriini, suggesting that Anthocoridae could not be monophyletic. We compared our molecular phylogeny to previous hypotheses of evolutionary relationships within Cimicoidea based on different anthocorid classification systems using alternative hypothesis tests (Kishino-Hasegawa and Shimodaira-Hasegawa tests). BayesTraits were used to examine the ancestral character states inferring historical habitat patterns of the Anthocoridae. Reconstruction of the ancestral habitat patterns of the Anthocoridae suggests that dead plants may have served as an important habitat for the common ancestor of anthocorids. The biological events such as diversification of angiosperms and anthocorid prey might have provided anthocorids with more habitat options, such as living plants; thereafter, Anthocorini and Amphiareus appeared to have evolved increasingly specialized habitat relationships.