| The cricket species Velarifictorus ornatus displays distinct wing dimorphism-individuals are either micropterous with much degenerate wings or macropterous with fully developed wings. Wing morph has been demonstrated to significantly affect reproduction of female v.ornatus, but whether it influences reproduction of male v. ornatus is still unclear. In order to find out any reproductive advantages of short-winged (SW) males over long-winged (LW) males, fertilization success of these two morphs of males was compared in this study. In addition, mating choice of females over SW and LW males was investigated, and effects of artifical removal of wings and vocal organs on mating choice of females were examinated, so as to illustrate female preference for SW males over LW males and mechanism underlying this phenomenon. The results are as follows:1. Sexual maturation time, mating frequency, and fertilization success of spermatophores after sequential mating in LW and SW adult males of V. ornatus were investigated. The results showed that SW males sexually matured earlier and produced heavier spermatophores during the early stage than LW males. Additionally, within a 24-h mating period, SW males mated more often and produced significantly heavier spermatophores than LW males (t-test, P<0.05 in both cases). A detailed comparison of spermatophore mass in each mating revealed that spermatophore weight decreased gradually with the increase of mating times, and SW produced heavier spermatophore than LW males in each mating (t-test, P<0.05) matings, and data were not analyzed thereafter because of limited samples). Female crickets were able to mate many times, which improved fertilization success but not significantly affected egg production of females. It seems that multiple mating may increase sperm numbers or sperm viability in spermatheca of females, increasing insemination rate of eggs. These results indicated that SW males invested more energy in reproduction than LW males, and this effort resulted in a higher fertilization success for SW males, increasing its reproductive output.2. When one SW male and one LW male were hold together to compete for one SW female, copulation success of SW males was 67.57%, which was significantly higher than that of LW counterpart (P<0.5). In addition, female preference for SW males did not changed by female morphs, male mating expericence and age. When hindwings of LW males were artifically removed, females chose SW males to copulate at a probability of 58.14%, which was not significantly different from that of their LW counterpart (P>0.05). When SW males were artifically removed a half of scraper, they obtained 68.57% successful copulations against intact LW male rivals. However, if scraper was totally removed from SW males, females chose less SW males than intact LW males to copulate. When both of LW and SW male were sound disabled, mating probability did not changed significantly between morphs (50% for each morph). It is suggested that the SW males have significant mating competitive advantage; dealation will improve the mating competitive ability of LW males, and sound of the male play an important role in courtship with female. Therefore, there is a trade-off between flight capability and reproduction in male V. ornatus, e.g. SW males are not able to fly, but have stronger mating competitive ability, while LW males reduce mating competitive ability in order to develop flight apparatus. |
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