Preferences and functional response of Coccinellidae to Bemisia tabaci (Hemiptera: Aleyrodidae)

An exploration study found that 4 out of 11 predominant predator species of Bemisia tabaci in Indonesia belong to Order Coleoptera, family Coccinellidae, i.e., Menochilus sexmaculatus, Coccinella transversalis, Verania lineata, and Curinus coeruleus. The current study was conducted to further determine the most effective predator species among those coccinellids. The evaluation included three consecutive assays, i.e., predation, preference, and functional response assay. The experiments were conducted in 2019 under controlled conditions in West Java. Predation assay using B. tabaci as the prey showed that M. sexmaculatus, C. transversalis, and V. lineata had comparable predation capacity to consume 46-48 nymphs d-1 or 9 adults d-1, and the V. lineata preference to B. tabaci was higher compared to other predators. Further logistic regression analysis (linear coefficient P1 =-0.1006, X2 = 34.99) showed that V. lineata had type II functional response characteristics. The analysis using the Hollings disc equation for type II functional response (R2 = 0.9239) suggested that the searching rate (a) and the handling time (Th) of V. lineata to B. tabaci nymphs were 0.3522 h-1 and 0.151 h, respectively. These results indicate that V. lineata could be considered in pest management strategies and effectively regulate populations of B. tabaci in Indonesia.