Evaluation of a philic egg-consumption predatory thrips Scolothrips takahashii for control of the citrus red mite Panonychus citri

Panonychus citri is a major pest mite that is of great economic importance in most citrus orchards in China. Utilizing native predatory natural enemies is one of the useful biological control strategies to maintain pest population below the level where damage occurs for an extended period of time. Although a handful of pesticides and predatory natural enemy species have proven effective on the integrated control of the citrus red mite, they are not hard-hitting tactics for control of the P. citri eggs due to the protection of egg-shell. This study evaluated the potential of a native species of philic egg-consumption predatory thrips, Scolothrips takahashii, for control of P. citri in southwestern Chinese citrus orchards. An age-stage, two sex life table of S. takahashii was constructed, showing this predatory thrips could develop and reproduce successfully when fed on all stages of P. citri. All the functional responses of S. takahashii adult males and females on different stages of P. citri fit the Holling II disc equation, whereas this predatory thrips preferred eggs of P. citri significantly more than their larvae or nymph. Mutual interference results indicated that the searching efficiency and predation rate of S. takahashii decreased significantly with increased predator densities when supplied with sufficient P. citri eggs. Overall, this study indicated the potential of S. takahashii as a biological control agent of P. citri and helped to characterize the role of native predatory thrips in pest mite management.