Sperm dynamics and cryptic male choice in tephritid flies

Variance in female quality can result in males discriminating females either through precopulatory or via postcopulatory choice. Male cryptic choice can be exhibited through copulation duration and strategic ejaculation. Female quality can also affect sperm storage distribution. Here, we studied sperm allocation in three tephritid flies with contrasting life histories and multiple sperm storage organs, Anastrepha ludens (MX flies), Anastrepha obliqua (WI flies) and Anastrepha spatulata (AS flies). In addition, for MX flies, we assessed the effect of female potential fecundity, size and diet on sperm allocation and the effect of female age on sperm storage distribution. Sperm distribution during copulation differed between species, which may be explained by their oviposition strategies. MX males mating with more fecund and younger females had shorter copulation durations. Female quality also influenced sperm storage patterns, as well-fed females stored more sperm in long-term sperm storage organs such as the ventral receptacle compared to malnourished females. Detailed studies on how female quality affects sperm transfer and sperm storage asymmetry will further our understanding on cryptic male choice.