Population Fitness of Fabricius (Diptera: Syrphidae) Feeding on Different Species of Aphids.

Fabricius, as one of the most common beneficial predatory insects in agricultural ecosystems, provides pollination and biological control services that help improve crop yield and maintain biodiversity. However, systematic research is needed on the species of aphids used for propagation. To develop highly fit populations of the important insect predator and crop pollinator, , for research and commercial use, further research is needed to develop the most nutritious diet and efficient propagation methods. Here, the fitness of was assessed in the laboratory after larvae were fed an aphid diet of Koch, Sulzer or Matsumura. The larval survival rate on was significantly lower than on and . The developmental duration for larvae (7.6 d) and pupae (6.9 d) was longest on . The pupal emergence rate on (98.0%) was significantly higher than on the other two, and lowest (64.7%) on . On , , and , respectively, the generation time was 24.85 d, 23.12 d and 21.05 d; the value for the intrinsic rate of natural increase was 0.19, 0.20, and 0.21; and the value for the finite rate of increase was 1.21, 1.22, and 1.23. For flight variables, attained the fastest velocity and longest distance and duration on . The diet, thus, provided the shortest generation time, the highest intrinsic rate of natural increase and finite rate of increase, the maximum fecundity and the greatest flight ability. Thus, to improve the survival rate of larvae, or can be used to feed newly hatched larvae, and can be used for second- and third-instar larvae. These results provide a theoretical basis for feeding and optimizing its ecosystem services.