Abstract: 【Aim】 The camphor sawfly, Mesoneura rufonota, is an important defoliator of the camphor tree Cinnamonum campora. The reproduction strategy of this insect includes gamogenesis and parthenogenesis. This study aims to clarify the biological significance of parthenogenesis in the life history of the camphor sawfly. 【Methods】 The differences in female reproductive fitness of M. rufonota including female adult longevity, fecundity and egg hatching rate and offspring life history traits including the duration of various developmental stages, mortality, sex ratio and fecundity of offspring between parthenogenesis and gamogenesis at the constant temperature of25℃were determined and analyzed. 【Results】 The female adult longevity of M. rufonota was longer for parthenogenesis than for gamogenesis, while the fecundity and egg hatching rate were similar between the two reproduction modes. There were no differences in the duration and mortality of various developmental stages and the fecundity of female offspring between parthenogenesis and gamogenesis. However, significant difference was found in the sex ratio of the offspring between parthenogenesis and gamogenesis, being displayed by that parthenogenesis resulted in male-biased sex ratio, while gamogenesis resulted in female-biased sex ratio. 【Conclusion】 The parthenogenesis of the camphor sawfly prolongs the longevity of female adult, which has been confirmed as arrhenotoky. These results showed that parthenogenesis of the camphor sawfly not only makes it possible to establish population, but also can provide a large number of males to offset the insufficient male individuals in gamogenesis.

Key words: Mesoneura rufonota, parthenogenesis, gamogenesis, reproductive fitness, developmental duration, sex ratio