Main predators of insect pests: screening and evaluation through comprehensive indices

Area of Science:

• Ecology
• Entomology
• Integrated Pest Management

Background:

• Predatory natural enemies are crucial for integrated pest management (IPM).
• Field-based screening and evaluation of key insect pest predators are underdeveloped.
• This study focuses on evaluating common spider species as predators of Ectropis obliqua in Chinese tea plantations.

Purpose of the Study:

• To screen and evaluate the predation efficacy of nine common spider species against the pest Ectropis obliqua.
• To identify the most effective spider predators for biological control in tea plantations.
• To establish comprehensive indices for predator evaluation in IPM.

Main Methods:

• Assessing spider species dominance and phenological overlap with E. obliqua.
• Utilizing targeted real-time quantitative polymerase chain reaction (qPCR) to detect E. obliqua DNA in spider guts.
• Estimating predation rates and numbers using DNA fragment detection and residual pest counts.

Main Results:

• Only four of the nine tested spider species preyed on E. obliqua.
• Neoscona mellotteei demonstrated the highest predatory potential, followed by Xysticus ephippiatus, Evarcha albaria, and Coleosoma octomaculatum.
• Predation efficacy was ranked using the Z-score method based on DNA analysis and gut content.

Conclusions:

• Neoscona mellotteei is identified as a promising biological control agent for E. obliqua in IPM strategies.
• A preliminary framework for screening and evaluating natural predators using comprehensive indices has been developed.
• This research contributes to advancing field-based predator assessment for sustainable pest management.