Effects of delayed mating on the fecundity, fertility and longevity of females of diamondback moth, Plutella xylostella

The effects of delayed mating on the copulation duration, female fertility, fecundity, egg fertility, longevity and the number days alive after mating of females of diamondback moth （DBM）, Plutella xylostella, were studied. When male mating was delayed, the female fertility, fecundity, egg fertility, longevity and number days alive after mating of DBM decreased, and there was a negative correlation between the age of the moth with those variables except copulation duration. When female mating was delayed, the female fertility, fecundity, percent egg fertility and number days alive after mating of DBM also decreased, but the longevity increased, which also showed a negative relationship between the age of the moth with the variables except copulation duration and longevity. When both males and females delayed mating, the female fertility and fecundity decreased; egg fertility was affected marginally, and the longevity of females increased. The moth age was negatively correlated with those variables.

Age-specific mortality and fecundity of a spider mite under diet restriction and delayed mating

Numerous experimental life-history studies on aging are mainly baised on two classical models—fruit fly Drosophila melanogaster(Meigen)and nematode Caenorhab-ditis elegans(Maupas)—with relatively little attention given to other organisms with different life-history characters.Two-spotted spider mite Tetranychus urticae Koch(Acari:Tetranychidae)differs from many other arthropods in that the females continue their growth in the early adult stage and can reproduce sexually and asexually.In this study,the influences of dietary restriction and delayed mating on the aging patterns of the spider mite were examined with the prevailing survival and reproduction trade-off hypothesis of aging being tested.Significant sex-specific responses of the spider mites were found.The females showed longevity extension on diet restriction(fasting for 2 days in every 4 days)compared with their counterparts being fed ad libitum,and after delayed mating for 9 days,while the males displayed a decrease in lifespan when experiencing diet restriction but were not significantly influenced by delayed mating.Path analysis was used to investigate the relationship between mite survival and reproduction traits,including longevity,female lifetime reproduction,age at first reproduction,early reproductive efforts and late reproductive efforts,yielding no evidence for trade-offs between these life-history traits.The additive effects of dietary restriction and delayed mating in lifespan extension of female spider mites were confirmed,proving that diet restriction is a robust anti-aging intervention,and that later onset of reproduction can prolong adult lifespan in females.