Predatory Efficiency and Functional Response of Hippodamia tredecimpunctata (Coleoptera: Coccinellidae) on Sitobion avenae at Different Temperatures

Abstract

Hippodamia tredecimpunctata (Coleoptera: Coccinellidae) is an important predatory ladybird beetle widely recognized for its role in the biological control of aphid pests in cereal agroecosystems. Sitobion avenae, commonly known as the grain aphid, is a major pest of wheat and other cereal crops, causing economic losses through direct sap feeding and transmission of plant pathogens. Understanding the predatory efficiency and functional response of H. tredecimpunctata under different temperature conditions is essential for optimizing its use in integrated pest management programs. The present study was conducted to evaluate the predatory capacity and functional response of H. tredecimpunctata feeding on S. avenae at different temperature regimes under controlled laboratory conditions. Various prey densities of S. avenae were offered to predator larvae and adults at different constant temperatures, and data on prey consumption, feeding behavior, developmental performance, and searching efficiency were recorded and analyzed. The results demonstrated that temperature significantly influenced the predatory efficiency and functional response of H. tredecimpunctata. Predation rates increased with rising prey density up to a threshold level, after which consumption stabilized, indicating a typical Type II functional response. Moderate temperature conditions promoted the highest feeding activity, prey searching efficiency, and predator performance, whereas extremely low or high temperatures reduced predation efficiency and feeding behavior. Both larval and adult stages exhibited strong predatory potential against S. avenae, although adults generally consumed a greater number of aphids compared with immature stages. Increased prey availability also enhanced predator activity and survival. The findings highlight the significant potential of H. tredecimpunctata as a biological control agent against cereal aphids under suitable environmental conditions. Understanding the temperature-dependent predatory behavior and functional response of this predator provides valuable information for improving biological control strategies and supporting sustainable aphid management in cereal production systems.