Traumatic insemination (TI), an extraordinary copulation strategy, is most prevalent in cimicoid true bugs (Insecta: Hemiptera) among invertebrates including insects. Here, we resolved the evolutionary history of TI and the females’ adaptations by conducting molecular phylogenetic analyses and comparative studies based on the phylgenetic relationships. We found a sister group relationship of Curaliidae + Lasiochilidae, which are the only groups among Cimicoidea not likely engaged in TI. Divergence time estimates revealed that TI is a behavior of antiquity that first evolved in the Early Jurassic 188Mya (95% highest posterior density = 157 – 221). Furthermore, ancestral character state reconstructions indicated that TI evolved only once from standard insemination in Cimicoidea. The results revealed that only TI is correlated with PS among the biological traits, and that evolutionary acquisition of PS was driven by selection of TI. Additionally, we found that not only are the three types of PS homoplastic to each other, but also that each of types could not be a homologous feature despite of same terminology, which suggests convergent evolution of the females’ morphology have occurred as females were adapting to TI.

Investigating the molecular clock, the ancestral character states, and the correlated evolution of discrete binary traits on phylogenetic trees, we studied the evolutionary history of the family Anthocoreidae, using ~3000bp of the mitochondrial 16S rRNA and nuclear 18S rRNA and 28S rRNA genes for 44 taxa. The BEAST and BayesTraits were used to examine the divergence times, cladogenesis, and historical habitat patterns. The correlated evolution of discrete characters was tested by reversible-jump Markov chain Monte Carlo. Our results suggest that (i) the ancestral habitat patterns of dead plants may have served as an important rule for the stem group of anthocorids; (ii) the radiation of angiosperms and the prey insect in the mid-Cretaceous might have provided anthocorids with more habitat options; and (iii) the transition of habitats played an important role for the change of ovipositor patterns in the family Anthocoreidae.

The flower bugs (Heteroptera: Anthocoridae) is usually known as biological control agents against various kinds of agricultural pests such as aphids, mites, thrips and so on. Since the classification of the family Anthocoridae has been controversial, the molecular phylogenetic study was conducted with 44 species including 6 outgroup taxa. Three genes, a total of 3277 bp of sequence data (nuclear 18S rDNA: 2022bp, 28S rDNA: 755bp, and mitochondrial 16S rDNA: 498bp), were analyzed using ML (maximum likelihood) and Bayesian methods, excluding MP (maximum parsimony) as the incongruence length difference (ILD) test has very low (0.001) P-values on all partition tests. Our results support the rank and monophyly of the family Lasiochilidae which was exclusively separated from the main clade of Anthocoridae proposed by Schuh and Stys (1991), and indicate the monophyletic relationships among tribes and genera within the family Anthocoridae. According to our results, the genus Amphiareus should be out of the tribe Dufourini and treated as the tribe level and The three genera, Blaptostethus, Scoloposcelis and Xylocoris should be placed to the family Lyctocoridae. We also propose the evolutionary theory of Anthocoridae based on their habitats, hunting behavior and the molecular phylogenetic results.