Functional Response of Chrysoperla carnea (Neuroptera: Chrysopidae) to Bemisia tabaci Nymphs at Different Temperatures

Abstract

The predatory lacewing Chrysoperla carnea (Neuroptera: Chrysopidae) is an important biological control agent widely used against whitefly pests in agricultural ecosystems. Temperature significantly influences predator–prey interactions and determines the efficiency of natural enemies under field conditions. The present study evaluated the functional response of C. carnea to Bemisia tabaci nymphs at different temperature regimes under controlled laboratory conditions. Predation experiments were conducted by exposing predator larvae to varying densities of B. tabaci nymphs across different temperature levels, and prey consumption rates were recorded over fixed time intervals. Functional response models were analyzed to determine the predatory behavior and feeding efficiency of C. carnea under changing thermal conditions. The results indicated that temperature had a significant effect on prey consumption, attack rate, and handling time of the predator. Predation rates increased with rising temperatures up to an optimum level, after which feeding efficiency declined under higher thermal conditions. The predator exhibited a Type II functional response at all tested temperatures, characterized by a rapid increase in prey consumption followed by a plateau at higher prey densities. Shorter handling times and increased attack efficiency were observed at moderate temperatures favorable for predator activity and metabolism. Conversely, low and excessively high temperatures reduced predator performance and prey utilization efficiency. The findings demonstrate the strong influence of environmental temperature on the biological control potential of C. carnea against B. tabaci populations. This study provides valuable information for optimizing the use of predatory lacewings in integrated pest management programs and improving biological control effectiveness in protected and open-field crop production systems.