This pest has two common names (pink mealybug and hibiscus mealybug), but there is an effort to standardize the common name by calling the pest "pink hibiscus mealybug," even though it attacks many plant species, including citrus.
The pink hibiscus mealybug is expected to attack many Florida crops including citrus, avocado, carambola, fig, guava, mango, soursop, and sugarcane; vegetable crops including asparagus, beans, beets, cabbage, peanuts, pigeon pea, cucumber, lettuce, pepper, pumpkin, and tomato; forest trees, and many species of ornamental plants including Allamanda, Angelica, Anthurium, Bougainvillea, Croton, ginger lily, Heliconia, Ixora, hibiscus, palm, and oleander.
Crop production costs will be increased if growers attempt to manage mealybug populations by pesticide applications. Pesticide applications will disrupt the effective natural enemies of other crop pests, such as mites, scale insects, and whiteflies leading to the application of additional pesticides to control these
pests. These additional pesticide applications can contaminate food, water and farm workers. Around the yard and home, insecticide use may also increase due to damage to ornamental plants, particularly hibiscus.
pink hibiscus mealybugs
Adult mealybugs are small (about 3 mm long) and pink in body color but covered with a waxy secretion. The waxy filaments are short and females are usually obscured by this white mealy wax. When adults are crushed their body fluids are also pink. Adult males are smaller than females, reddish brown and have one pair of wings. Males have two long waxy "tails."
Females die shortly after depositing eggs. Freshly-laid eggs are orange, becoming pink before they hatch. Eggs are found in egg sacs. First instar nymphs (crawlers) of the pink hibiscus mealybug disperse by walking and by wind. Nymphs also can walk considerable distances to find suitable host plants. The life cycle takes about 23 to 30 days. The pink hibiscus mealybug has a high reproductive rate (females can deposit up to 600 eggs) and produces up to 15 generations per year, so pest populations can become very large.
Pink hibiscus mealybug eggs overwinter in bark crevices, leaf scars, under bark, in the soil, tree boles, inside fruit clusters, and inside crumpled leaf clusters.
Pink hibiscus mealybug feeds on the soft tissues of many plant species and injects a toxic saliva that causes curling and contortion of leaves. The entire plant may be stunted and the shoot tips develop a bushy appearance. Buds may not flower and stems may twist. Fruit may also be deformed. The mealybug excretes honeydew which encourages the development of black sooty mold. Very high mealybug populations can kill plants.
The level of feeding damage depends on the vigor of the infested plant; seedling trees and weakened trees are more susceptible. Shoots become twisted with shortened internodes, forming bunchy heads of small bushy leaves at the tips. The curled leaves can resemble viral damage, but this pest is not known to vector any diseases. Heavy infestations of young plants by the pink hibiscus mealybug may stunt their growth.
The mealybug is found on stems, leaves, buds, fruit and roots of many plants. On hibiscus, the mealybug usually infests young twigs, causing deformed terminal growth due to shortening of the internodes, deformed leaves and thickened twigs. In cotton, the growing parts are attacked, resulting in bunchy growth. Plants
are stunted and produce fewer bolls of a smaller size. Boll opening is adversely affected and yield reduction occurs. In grapevines, the mealybug feeds on sprouts after pruning; heavily infested bunches shrivel and drop. In peanut, the mealybug can feed on the underground parts of the roots, pods, and pegs of the plant, resulting in stunted growth and poorly developed pods.
The ladybug Cryptolaemus montrouzieri is known to feed on all stages of the mealybug. This beetle already is established in Florida and also is available commercially. The appropriate release rate for this ladybug is unknown. Predatory ladybugs may provide some suppression of high pest populations, but are not expected to provide adequate control of lower populations because the beetles require large numbers of mealybugs to survive.
Cryptolaemus larvae are covered with a white flocculent secretion and may be confused with pink hibiscus mealybugs but are important predators and should not be destroyed.
The pink hibiscus mealybug is a good candidate for classical biological control. Several effective parasitoids are known in Asia and elsewhere. One parasitoid, Anagyrus kamali, completes a generation in less than half the time required for its host. Anagyrus kamali has been reported to be an outstanding natural enemy in Egypt and Hawaii and is able to dramatically suppress pink hibiscus mealybug populations. This parasitoid has been released on islands in the Caribbean and appears to be providing substantial control already. Pink hibiscus mealybugs parasitized by A. kamali produce "mummies" and have an exit hole where the adult wasp emerges.
parasitized mealybug "mummies"
Several other parasitoid species also are known to attack the pink hibiscus mealybug. These parasitoids will be evaluated for their host specificity and may be released when more is known about their biology.
Classical biological control projects often take several years to conduct. In order to shorten the time it will take to conduct a classical biological control program on the pink hibiscus mealybug, we have made contact with scientists in the native range of these pests for assistance in identifying sites where
natural enemies can be collected and we have obtained permits for importing these natural enemies into quarantine for evaluation. The USDA-APHIS also has agreed to provide starter cultures of parasitoids for evaluation, rearing, and release in Florida. Natural enemy species have been identified for which a
substantial amount of information is available, which means that permission to get these species out of quarantine for mass rearing and release in Florida will be expedited once we know the pest is here in Florida.
If you find this mealybug pest on plants (especially hibiscus) at your home or farm, please send suspect pink hibiscus mealybug specimens to:
Division of Plant
Industry
PO Box 147100
Gainesville, FL 32614-7100
Authors: Marjorie A.
Hoy, University of Florida, Avas Hamon and Ru Nguyen, Division of Plant Industry
Photographs: Dale Meyerdick, USDA-APHIS; Marshall Johnson, University of Hawaii; Lance Osbrne, University of Florida
Project Coordinator: Thomas R. Fasulo, University of Florida
Publication Number: EENY-29
Publication Date: May 1998. Latest revision: September 2006.
Copyright 1998-2006 University of Florida
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Department of Entomology and Nematology
Division of Plant Industry
Electronic Data Information Source
eggs
adult female and immatures
adult male
damage to hibiscus
damage to hibiscus
feeding damage on citrus
adult ladybug beetle
immature ladybug beetle