Functional Response and Mutual Interference of Orius albidipennis (Hemiptera: Anthocoridae) on Thrips tabaci Larvae

Abstract

The predatory anthocorid bug Orius albidipennis is an important biological control agent of thrips in vegetable and protected cultivation systems. Laboratory experiments were conducted to evaluate its functional response and mutual interference when feeding on larvae of Thrips tabaci. Predation trials were performed under controlled environmental conditions by exposing different prey densities to individual and group-reared predators to assess consumption rates, handling time, and search efficiency. Results indicated a typical Type II functional response, characterized by a rapid increase in predation rate at low prey densities followed by a gradual plateau at higher densities due to handling time constraints. Estimated parameters revealed high attack efficiency and effective prey consumption, demonstrating strong predatory potential of O. albidipennis against T. tabaci larvae. Mutual interference experiments showed a decline in per capita predation rate with increasing predator density, indicating intraspecific competition and reduced foraging efficiency under crowded conditions. Interference coefficients suggested moderate levels of predator interaction, which may influence field-level biological control efficiency. Feeding activity was significantly affected by prey density, predator density, and environmental conditions, with higher consumption observed at intermediate prey availability. The predator exhibited active searching behavior and rapid prey capture, contributing to effective suppression of thrips populations under laboratory conditions. The findings highlight the importance of understanding both functional response and mutual interference in predicting field performance of biological control agents. Orius albidipennis demonstrates strong potential for integration into thrips management programs, particularly in greenhouse vegetable production systems where T. tabaci is a persistent pest.