Figure 1.

Phylogeny of the Cimicomorpha (Heteroptera). Taxa in bold are those which practice TI, while numbers indicate characters associated with TI. (a) Intragenital TI: in the Prostemmatinae the male inserts his genitalia into female genital opening and punctures the wall of the genital tract with a sharp process on the aedeagus (the acus). (b) Extragenital TI: in these taxa TI is extragenital (i.e. the male pierces the female body wall with his genitalia, never entering her genital tract). (c) Paramere and aedeagus coupled: the Plokiophilidae and Lyctocoridae puncture the female with an acus, while in the Anthocoridae, Polyctenidae, Cimicidae as well as the mirid genus Coridromius, the male's left paramere is coupled with the aedeagus, forming a scythe-like piercing intromittent organ. Adapted from Schuh & Štys 1991.