Evaluation of potential natural enemies of hibiscus mealybug, Nipaecoccus viridis (Hemiptera: Pseudococcidae) in Florida citrus

Abstract

Abstract Hibiscus mealybug Nipaecoccus viridis (Newstead; Hemiptera: Pseudococcidae) is a newly established pest in Florida citrus. In its native range, hibiscus mealybug is controlled by a suite of natural enemies. However, the potential predator population for this pest in Florida is currently unknown. Identifying and promoting natural enemies that prey on hibiscus mealybug in the newly established region are key to achieving sustainable management of this pest. We evaluated commercially available predators and field-collected predators for the ability to consume juvenile life stages of hibiscus mealybug. Additionally, we evaluated an augmentative release of Cryptolaemus montrouzieri (Mulsant; Coleoptera: Coccinelidae) inside of a citrus under protective screen (CUPS) production system to control a hibiscus mealybug infestation. In no-choice assays, we found that the commercially available predator Cr. montrouzieri consumed all juvenile stages of hibiscus mealybug, and another, Chrysoperla carnea (Stephens; Neuroptera: Chrysopidae), was able to consume eggs but showed a clear preference for nymphs. Other commercially available predators did not consume any juvenile life stage of hibiscus mealybug. Two field-collected predators consumed both nymphs and ovisacs at high rates in no-choice tests: Euborellia annulipes Lucas (Dermapter: Anisolabididae) and Ceraeochrysa sp. (Neuroptera: Chrysopidae). Moreover, ten species of natural enemies were identified from mealybug clusters sampled from the fields among which two predators, Fragosa sp. (Diptera: Syrphidae) and Anatrachyntis badia (Hodges; Lepidoptera: Cosmopterigidae), and two parasitoids, Anagyrus dactylopii (Howard; Hymenoptera: Encyrtidae) and Aprostocetus sp. (Hymenoptera: Eulophidae) were found in high abundance. In the augmentative release, we found a reduction in pest population after the release of Cr. montrouzieri. However, without additional resources to maintain the predator, hibiscus mealybug population increased once the beetle population died. Our results indicate that Cr. montrouzieri is an effective commercially available predator of hibiscus mealybug and that several naturally occurring predators and parasitoids prey on hibiscus mealybug in Florida citrus.