Indian River County Extension Service
1028 20th Pl, Suite D
Vero Beach, FL 32960
Daniel F. Culbert, County Extension Director Press Release Date June 30, 2002
Indian River County Agriculture Extension Service
ARE YOUR MEALYBUGS PINK?
There may soon be a new bug in town, and although its soft and pink, it wonít be very cuddly on many of our landscape and house plants. Thereís been a flurry of media attention on a new insect invader from Asia that has recently been discovered in Broward County. Todayís column will introduce you to the Pink Hibiscus Mealybug, and give some details about where it has been and how to look out for it.
Unfortunately, the what to do about it part of the story is being rewritten as you read this column. University of Florida Entomologists are meeting this week with USDA researchers and Florida Department of Agriculture officials to develop the best strategies to deal with this pest. Information for todayís column comes from University of Florida Entomologists Lance Osborne, Catharine Mannion, and Bill Howard.
Lifestyles of the Pink and Puffy
This pest is generally called by the common name, pink hibiscus mealybug (Maconellicoccus hirsutus), even though it attacks many plant species, including citrus. It has also been called pink mealybug and hibiscus mealybug. With the recent find of the Pink Hibiscus Mealybug (PHM) in the Miramar area of Broward county, three exotic mealy bugs have recently found their way into Florida.
Over 275 species of mealybugs are known in the Continental US. Mealy bugs are related to a large complex group of insects, including aphids, whiteflies, and the scale insects. Most of these insects are sapsuckers, and use a straw-like mouth part to feed on the sap of their host plant. In the process of feeding, they can inject plant toxins or diseases.
Adult mealybugs are small (about 1/16 inch 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. In comparison with other mealybugs, there is less wax on the body, stripes are less apparent, and females lack long tails or waxy projections around the edge. Adult males are smaller than females, reddish brown and have one pair of wings and two long waxy "tails." When squashed, a pink to red fluid is observed - that is the identifying feature that distinguishes PHM from other mealybugs.
The pink hibiscus mealybug has a high reproductive rate:
females can deposit up to 600 eggs during their 23 to 30 day life cycle, and up
to 15 generations of PHM per year can be produced. This is why pest populations
can become very large, very fast.
The PHM is believed to be a native of southeast Asia, and has spread to Africa and northern Australia. It may be spread naturally by wind, birds, and other wildlife, or by people moving infested plant material to non-infested areas. Since it arrived in Grenada in 1994, the PHM has moved to Guyana and at least 14 Caribbean islands. The USDA has been working valiantly to keep this pest out of our county for the past 10 years, but because of the wide host range, Pink hibiscus mealybugs are expected to eventually colonize all of Florida and spread north into southern Georgia.
Look for PHM on all parts of plants, but focus in on the more succulent and protected areas of the plant: buds, undersides of leaves, inside the joints between twigs, and even down in the feeder roots in the soil. The PHM sucks juices from its host plant and injects a toxic saliva as it feeds. This feeding habit distorts leaves and fruit, and stunts leaves and terminal growth. Mealybug feeding can kill the plant. One or more of the following symptoms on host plants may be seen:
Crinkled or twisted leaves and shoots
Bunched and unopened leaves
Distorted or bushy shoots, called "Bunchy top"
White fluffy mass on buds, stems, fruit, and roots
Presence of honeydew, black sooty mold, and ants
Unopened flowers which often shrivel and die
Small deformed fruits.
While the PHM does attack Hibiscus, the list of plants that it can infest is very long. UF Entomologists have identifies more than 332 host plants. Here is a short list of some of our local plants that are know to be effected by the PHM:
Fruit trees: Avocado, Banana, Carambola (Star Fruit), Citrus, Grape, Guava, Mango Papaya, Passion Fruit.
Vegetables: Tomato, Peppers, Beans, Cucumber, Pumpkin, Squash, Okra, Lettuce, Cabbage.
Ornamentals: Allamanda, Anthurium, Bougainvillea, Croton, Ficus, Ginger Lily, Heliconia, Hibiscus, Ixora, Lantana, Oleander, Schefflera, Seagrape.
Predators , parasites and pesticides
The best hope for coping with the eventual arrival of this unwanted visitor seems to be the release of predatory and parasitic insects which will keep the numbers to tolerable levels. The successful introduction of these good guys will depend upon the release of and establishment of populations of hungry helpers. And, the use of pesticides in our Florida Yards to control the PHM may also kill these predators and parasites. Bottom Line: at this point, donít spray pesticides for this pest until specific homeowner recommendations are developed.
Several good guys are being proposed to put the bite on PHM. One is a very small parasitic wasp (Anagyrus kamali) that lays an egg inside the mealybug adult. The egg hatches into a maggot, feeds inside the PHM and kills the pest. After pupating, the adult parasite chews an exit hole in the empty shell of the PHM and emerges. One females wasp can take care of 40-60 mealybugs in 15 days. The adult also pierces the mealybug shell and feeds on the pestís body fluids.
The wasp does not sting people and feeds only on mealybugs. The USDA has reported a 94 percent reduction in pink hibiscus mealybugs in the year and a half since these wasps were introduced in St. Kitts and more than an 80 percent reduction in only four months in Puerto Rico.
Another good guy is the redheaded ladybird beetle (Cryptolaemus montrouzieri), whose larvae is sometimes called the mealybug destroyer. A voracious feeder on mealybugs, this predaceous beetle is capable of eating 3,000-5,000 mealybugs during its lifetime. Because of their heavy wax coating, the larvae of this beetle are often mistaken for large mealybugs. But, these beetles can interfere with the parasitic wasp because the beetles will also feed on parasitized mealybugs. This is another reason why the local pest management strategies are not yet clear.
How you can help
If you travel outside the country, make sure that all plants, fruits, and vegetables brought into the United States, particularly from Central America and the Caribbean, are properly inspected and cleared at U.S. ports of entry. This will slow the spread of this pest.
Monitor your landscape, fruit and vegetable plants for signs of this insect. Look at any new plants before you bring them into your landscape. Be on the lookout for white fluffy masses on buds, stems, fruit, and roots.
Because pesticides cannot easily penetrate the heavy wax layers on the PHM, many pesticides will be ineffective against this mealybug. Donít spray until recommendations are developed.
Report suspected pink hibiscus mealybug infestations to our Extension office; our staff will be able to give you contact information for Florida Department of Agriculture or USDA staff directly. We will be able to assist in PHM identification and offer management strategies as they become available.
Our office can provide you with Internet links or copies of several fact sheets about the Pink Hibiscus Mealybug from University, State and Federal sources. In the mean time, be on the lookout and bring suspected samples fully enclosed in containers to our office if you suspect it is on your plants. As soon as we receive recommendations on how to best manage this pest, we will pass it along through this paper and on our County Extension website, .
If you need additional information on pests in your Florida Yard, our office holds Master Gardener Clinic hours at the Extension office (1028 20th Place, Suite D, Vero Beach) every weekday morning and most afternoons, Wednesday morning at the North County Library in Sebastian, and the first Saturday of the month at the Environmental Learning Center. Our phone number is 770-5030, and you can e-mail us at Indian@mail.ifas.ufl.edu
Pink Hibiscus Mealybug references
Eversole, Chris. "SEARCH FOR PEST TURNS UP DANGEROUS COUSIN, UF RESEARCHER SAYS." UF News Release, March 24, 1999.http://www.napa.ufl.edu/99news/papaya.htm
Hoy, Marjorie A., Hamon, Avas and Nguyen, Ru. Pink hibiscus mealybug (Feature Creatures Fact Sheet). Gainesville: UF/IFAS, May 1998 EENY-29.http://creatures.ifas.ufl.edu/orn/mealybug/mealybug.htm
Miller, Douglass Surveying for PHM: Distinguishing Field Characters Identifying Life Stages. (Extracted from: USDA-APHIS Pink Hibiscus Mealybug Project Manual). Washington: Systematic Entomology Laboratory, USDA, ARShttp://www.mrec.ifas.ufl.edu/lso/mealybug/Pages%20from%20phm.pdf
Osborne, Lance Photos of various mealybug including the Pink Hibiscus Mealybug. (Insect and Mite Update) Apopka: UF/IFAS Mid Florida REC, June 2002. http://www.mrec.ifas.ufl.edu/lso/Mealybugs.htm
Pink Hibiscus Mealybug, Maconellicoccus hirsutus (Green.) FDACS/DPI Pest Alert fact sheet, June 18, 1999 http://doacs.state.fl.us/~pi/enpp/ento/pink.htm
Watch Out for the Pink Hibiscus Mealybug. USDA APHIS Program Aid No. 1606.http://www.bugwood.org/factsheets/mealybug.html
University of Georgia Entomology & Forest Resources Library : The Bugwood Network January 18, 2000. http://www.bugwood.org/factsheets/mealybug.html