Female mate preference in an invasive phytopathogen vector: how learning may influence mate choice and fecundity in D iaphorina citri

Abstract In some arthropods, females learn in the context of reproduction to refine their mate choices and avoid males displaying traits associated with impotency. Previous studies have shown that males of the Asian citrus psyllid, D iaphorina citri K uwayama ( H emiptera: P syllidae), associate female odor with copulatory rewards. However, it is unclear whether females similarly learn about male traits. We compared mate choice in females previously mated to either blue or orange males and found that females may associate male color with reproductive success, and avoided blue males after previous experience. Orange males mated more frequently than blue males and appeared to be more sexually aggressive in their mating attempts. In addition, females mated to orange males laid approximately twice as many eggs as those mated to blue males. We dissected male psyllids and measured the size of their reproductive organs to determine whether abdominal color was associated with reproductive development. Our morphometric analysis indicated that blue males may not be physiologically immature compared with orange males. Rather, blue males displayed larger testes and seminal vesicles than orange males, suggesting that differences in reproductive output may be behavioral in nature. Based on our data, we suggest that females learn about the appearance and mating behaviors of blue and orange males from early mating experiences, and subsequently avoid blue males in future matings. Although the roles of blue males within a population are unclear, it is possible that blue morphs may specialize in other functions such as dispersal.