Functional Response, Interference, and Predation Efficiency of Diomus guilavoguii (Coleoptera: Coccinellidae) on Paracoccus marginatus (Hemiptera: Pseudococcidae)

Paracoccus marginatus (Hemiptera: Pseudococcidae) poses a significant threat to over 200 plant species, severely impacting agricultural productivity. Diomus guilavoguii (Coleoptera: Coccinellidae) is a natural predator of P. marginatus. To develop an effective and environmentally friendly management strategy against P. marginatus, this study investigates the predation relationship between D. guilavoguii and P. marginatus by focusing on functional response and mutual interference under controlled laboratory conditions (Petri dishes). The results indicated that D. guilavoguii exhibits a type II functional response toward P. marginatus, with adults of D. guilavoguii demonstrating superior efficiency in preying upon P. marginatus (the theoretical daily maximum predation rate for female adults of D. guilavoguii on young mealybugs is 416.667). However, a decrease in the predators’ search effect was observed with increasing prey density. Additionally, interspecific interference competition intensified as the number of predators increased, resulting in reduced predation efficiency. Consequently, D. guilavoguii shows promise biological control agent for the management of P. marginatus under laboratory conditions, although further studies in greenhouse and field environments are required to validate its potential in practical pest management.