Temperature-Dependent Demographic Characteristics and Control Potential of Aphelinus asychis Reared from Sitobion avenae as a Biological Control Agent for Myzus persicae on Chili Peppers.

Sheng Yin Wang,Da Yu Zhang,Bo Li Wang,Tong Xian Liu,Yan Hong Liu,Gai Lan Yan

doi:10.3390/insects11080475

Abstract

Aphelinus asychis, a polyphagous parasitoid, has been widely used as an efficient biological control agent against the aphid Myzus persicae. Aiming to evaluate the influence of temperature on the biological characteristics and control potential of A. asychis for M. persicae, we compared the life table parameters and control potential of A. asychis, which included the developmental time, longevity, fecundity, intrinsic rate of increase (r), and finite killing rate (θ). The results showed that increasing the temperature significantly decreased the developmental time and longevity of A. asychis. The r at 24 (0.2360 d−1) and 28 °C (0.2441 d−1) were significantly greater than those at 20 (0.1848 d−1) and 32 °C (0.1676 d−1). The θ at 24 (0.4495), 28 (0.5414), and 32 °C (0.4312) were also significantly greater than that at 20 °C (0.3140). The relationship between population fitness (r and θ) and temperature followed a unary quadratic function (R2 > 0.95). The temperatures for the expected maximum intrinsic rate of increase (rmax) and the maximum finite killing rate (θmax) were 25.7 and 27.4 °C, respectively. In conclusion, A. asychis could develop and produce progenies within the temperature range of 20–32 °C, and its control efficiency for M. persicae at 24, 28, and 32 °C was greater than that at 20 °C. The most suitable temperature range for controlling M. persicae with A. asychis in the field might be between 25.7 and 27.4 °C.

Highlights

The chili pepper (Capsicum annuum, Solanaceae) is an important vegetable and condiment planted in greenhouses and open-air fields in China [1]
Myzus persicae were reared on chili pepper plants (90 days old), and A. asychis was fed on S. avenae, which fed on winter wheat plants
The winter wheat plant, the chili pepper plant, M. persicae, S. avenae, and A. asychis were reared in a phytotron (photoperiod, 14:10 h (L/D); illumination intensity, 10,000 ± 50 lx; 25 ± 0.5 ◦ C; and 70 ± 10% RH (Relative Humidity)) at Northwest A&F University, Shaanxi, China

Summary

Introduction

The chili pepper (Capsicum annuum, Solanaceae) is an important vegetable and condiment planted in greenhouses and open-air fields in China [1]. The green peach aphid (Myzus persicae) is a sucking pest of more than 400 host plant species covering 40 families, including the chili pepper [2,3]. It is an important vector of more than 100 plant viruses [2]. In the past few decades, the intensive use of chemical insecticides such as carbamate [5], pyrethroid [6], cyclodiene [7], neonicotinoid [8], and many others to control M. persicae has resulted in their development of resistance to these chemicals. Chemical insecticides have tremendous negative impacts on beneficial organisms and the environment [9,10,11]

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Discussion

Conclusion