Group-reared life table analysis reveals sugar supplementation improves fitness of parasitic wasp (Hymenoptera: Aphididae)

The nutritional status of the parasitic wasp Aphidius gifuensis Ashmead (Hymenoptera: Aphididae) is a critical factor affecting its physiological activities, which are key to mass reproduction and field application. In this study, we constructed an age-stage, two-sex life table under a group-rearing conditions by feeding adult A. gifuensis with 5% (w/v) solutions of honey, fructose, glucose, or sucrose. The results showed that fructose, sucrose, and glucose significantly extended the longevity of male A. gifuensis compared to the water control. However, fructose, sucrose, and glucose had no significant impact on the longevity of female A. gifuensis. Sugar-fed parasitoid wasps had significantly shorter mean generation time compared with control, with parasitoids fed with glucose having the shortest mean generation time. The order of intrinsic rate of increase (rm) by treatment was Sucrose (0.4140), Glucose (0.4039), Honey (0.3911), Fructose (0.3903), and Water (0.3679). The rm were significantly higher in the glucose and sucrose treatments than in the water control. Additionally, the peaks of age-stage-specific reproductive value (vxj) by treatment were: Sucrose (190.15), Glucose (154.56), Honey (147.64), Fructose (139.41), and Water (104.05). Fructose, glucose, and sucrose treatments significantly increased female fecundity compared to the control, with sucrose-fed females showing the highest fecundity among the sugar treatments. These results demonstrate that sugar supplementation positively affects the reproduction of A. gifuensis. Both sucrose and glucose resulted in significantly higher rm values in adult, highlighting their effectiveness as nutritional supplements. Considering the lower cost of sucrose compared to glucose, sucrose is recommended as a dietary supplement for adults in mass production and field applications.