| Age of female and male were a major determinant in shaping the fecundity functions of insects. The age of mating individuals is apparently a key factor in reproduction with effects on their sexual performance and progeny production. It is widely held that females should prefer to mate with older males in species where males provide only sperm to females, because viability selection leads to older males of higher genotype quality than younger males. However, some have argued that males of young and intermediate ages are better mates, as they have the highest breeding value for fitness and are less prone to deleterious mutations.Harmonia axyridis (Pallas) is subordinated to Coleoptera,Coccinellidae. It is one of important predatory natural enemies in agriculture and forestry systems. The ladybird preys on many pests. Due to oviposition duration, large number of eggs laid, large appetite, high fecundity, adaptability, many generations and long adult longevity, Harmonia axyridis(Palias) is a kind of important predators on extractive industry. It is widely used in biological control, with good development prospects. In this study, to evaluate age as a variant factor, experiments were designed to determine its influence on reproductive performance of Harmonia axyridis. In order to test available genetic mating and reproduction age guidance. The results were as follows:1. Females began mating at Ten-day-old. Five-day-old male elytra and hardened after maturation, but sexual function is not complete, it still has low sperm viability, and prone to fertilization failure. Ten-day-old male sexual development has been completed and has strong features. Females developed slowly than males, Five-day-old female elytra is not hard, Ten-day-old female develop post-mature.2. Five-day-old male of Harmonia axyridis started mating with 10d younger female. However, females do not lay eggs after mating. Ten-day-old male mated with Ten-day-old female or older female, spawning and hatching.3. Mating duration was found to be dependent on the age of mating partners. With the increase of female age, mating during was more and more long. And that maximum mating duration occurred 22.0 and 21.0 days after emergence in males and females. Then, With the increase of female age, mating during was more and more short. When 20d female mated with 20d male, there was a maximum mating duration, 222.16±1.42min. Mating shaking time followed a similar pathway with mating duration. It is possibly due to the increased intensity of the older male's urge to mate or to prolonged or multiple sperm transfer due to prolonged mate deprivation.4. Age have a regulating role in fecundity of female. Fecundity was significantly dependent on female age with 20 day-old mated female exhibiting maximum fecundity. When 20d female mated with 20d male, there was a maximum fecundity, 2126.30±69.31 eggs.5. Age does affect the viability of eggs. As the eggs sired by 30 day-old males mated with female were more viable than those sired by younger males, is 84.85±1.32 %.6. Age also affect the longevity of female. The longest longevity of female is 73.80±1.98day and the shortest longevity of female is 73.80±1.98d.7. Trends of mating duration were found similar to those of fecundity and egg viability with maximum mating duration coinciding with high fecundity and egg viability. This suggests that prolonged matings may result in deposition of increased quantity of sperm, which are stored in the spermathecae by the females to fertilize the ova during non-mating conditions and may result in increased lifetime fertility.8. Adults of Harmonia axyridis 20d intermediate age are best mates and can produce best reproductive performance. |
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