D3470: Functional response of Aphidius colemani (Hymenoptera: Braconidae) on the green peach aphid under different carbon dioxide concentrations

In this study, we investigated the functional response of aphid parasitoid, Aphidius colemani Viereck (Hymenoptera: Braconidae), on the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae). Three carbon dioxide concentrations (400, 600, and 1000 ppm) and seven host densities (2, 4, 8, 16, 32, 64, and 128) were used during a 24-h period. At each CO₂ concentration, 2-128 third-instar nymphs of M. persicae were exposed to individual wasp. A type III functional response for A. colemani was fit separately for each CO₂ concentration. The estimated handling time (Th) under elevated CO₂ (600 ppm and 1000 ppm, 0.015 and 0.014 day) was shorter than that under ambient CO₂ (400 ppm, 0.017 day). The proportion of aphids that were parasitized showed the similar characteristic curve under three CO₂ concentrations. The highest parasitized rates for A. colemani were 0.57, 0.61, and 0.70 at 16, 32, and 32 aphid density under 400, 600, and 1000ppm, respectively. Although handling time of A. colemani was influenced by elevated CO₂ concentrations, the attack rate was not changed much. A. colemani maybe more effective for biological control of the green peach aphid under elevated carbon dioxide concentrations.

Acknowledgements: This research was supported by the research program of RDA (PJ01606002)