Life History and Predatory Behavior of Euborellia annulata (Dermaptera: Anisolabididae) on Papaya Mealybug (Paracoccus marginatus)

Abstract

This paper reports the life history of Euborellia annulata (Fabricius) and its predatory behavior against the papaya mealybug, Paracoccus marginatus Williams and Granara de Willink, under laboratory conditions (25 ± 2°C and 70 ± 5% RH). 10 2nd generation adult pairs of E. annulata were allowed to mate, oviposit, and complete their development while feeding exclusively on P. marginatus. The setup was arranged in a Completely Randomized Design (CRD) with three biological replicates. Results indicate that mating to oviposition occurred after a short pre-oviposition period of 5.46 days, while egg incubation was completed approximately 6-8 days. E. annulata underwent four nymphal instars before reaching adulthood. The first lasted 7.20 days, while the second instar lasted 5.73 days. Third required 8.07 days before transitioning to the fourth and final nymphal stage. The fourth exhibited the longest developmental duration of 9.20 days. Adults were characterized by a smooth, glossy black exoskeleton. Sexual dimorphism was evident through differences in cercal morphology. Predation involved prey assessment and repeated attempts at attack before successful capture and consumption. An individual earwig required 30–40 minutes to consume a single mealybug nymph. This, however, suggests relatively high prey-handling costs which might be associated with overcoming the waxy defenses of P. marginatus. Although the predator readily accepted and consumed the mealybug, prolonged handling time may constrain its maximum predation rate under high pest densities. Further studies are needed to evaluate the functional response, habitat overlap with arboreal pests, and field-level efficacy within integrated pest management programs.