Distinct behavioural strategies underlying asymmetric mating interactions between invasive and indigenous whiteflies

Knowledge of animal mating strategy may provide insight into the evolution of mating behaviour, speciation, and species competition interactions. Our previous study showed that asymmetric mating interactions between invasive and indigenous species of the worldwide distributed whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) complex contribute to invasion and displacement. Here, we reobserved in detail the video recordings of mating behaviour and behavioural interactions of a previous study and did an integrated analysis on the new data obtained here and some aspects of the data reported earlier. We compared the mating strategies of an invasive whitefly species and an indigenous congeneric competitor from each of two geographic regions, China and Australia. We found that in both regions, females of the invasive species had higher propensity to copulate than those of the indigenous species. In addition, females of the invasive species increased their frequency of copulation in response to increases in courting by males. Compared with males of the indigenous species, those of the invasive species were more likely to court per unit time as well as to interrupt courting pairs, and they also exhibited shorter durations of copulation. In addition, males of the invasive species exhibited post-copulatory guarding behaviour, whereas those of the indigenous species did not. The different mating strategies exhibited by the invasive and indigenous species may be the evolutionary basis of their asymmetric mating interactions. Such differences in mating strategies confer on the invasive whitefly species the capacity to both invade and displace indigenous whitefly competitors.