Sept. 17, 2007

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PORT ARANSAS – The pink hibiscus mealybug – which may be of concern to Texas, citrus and ornamental industries – has been found near Port Aransas.

"This mealybug is a potentially serious pest of many ornamental and agricultural crops," said Dr. Carlos Bogran, Texas Cooperative Extension entomologist.

First discovered in the U.S. in Florida in 2002, the pink hibiscus mealybug has also been found in California and Louisiana.

It feeds by sucking plant sap from more than 300 species in 74 plant families, Bogran said.

The total value of ornamentals in Texas was $9.8 billion in 2005 – the latest figures available – placing the state third in the nation behind California and Florida, said Marco Palma, Extension economist. That includes the growers, retailers and landscapers, he said. Grower sales alone were $1.3 billion.

The Texas commercial citrus production of fruit (not juice) was valued at $74 million in 2006 and averaged $81.3 million over the last two seasons, Palma said. Texas is the third largest citrus producing state behind Florida and California.

Pink hibiscus mealybug adults and nymphs look much like other mealybug species but have some distinguishing characteristics that help in identification, Bogran said.

Female adults have no wings and are covered with white wax, and adult males are winged and have two long, waxy tails, he explained.

Females may deposit eggs in waxy ovisacs (egg masses), and young nymph- crawlers emerge to find new feeding sites, especially in tender new plant growth, he said.

Most other mealybugs have a fringe of wax filaments that surrounds their body, he said.

"They disperse in wind currents, by crawling from plant to plant, or by movement of infested plant material or even when stuck on clothing," Bogran said.

Pink hibiscus mealybug infestations can also be distinguished from other species in other ways: Feeding causes new leaves to curl; young stems stop elongating and become thick, giving a ‘bunchy-top' appearance, he said.

Colonies and egg masses are protected by wax accumulations, making the control of the pink hibiscus mealybug with contact insecticides difficult, he said.

"Systemic insecticides may provide some control but are not always effective because eggs and young crawlers can escape exposure," he said.

"Insecticides are also toxic to natural enemies that help to keep populations under control. Long term management of this pest will rely on biological control; two species of parasitic wasps have proven effective in Florida and will also be released in Texas," he said.

Anyone who suspects a pink hibiscus infestation can go to the Extension Bookstore site at http://tcebookstore.org (click on Insects and then Crops) and download publication E-454, he said. Another source of information is the University of Florida Web site at http://mrec.ifas.ufl.edu/LSO/PinkMealybug.htm , he added.

Dr. Boris Castro, an entomologist at the Texas A&M University System Agricultural Research and Extension Center at Weslaco, said although the insect has not been detected in the Lower Rio Grande Valley, it is important to remain vigilant.

"We're asking nurseries, wholesalers, retailers and homeowners to be on the lookout for symptoms of the pink hibiscus mealybug, especially on new plant growth. The earlier we spot any new populations here, the better our chances of managing populations by releasing natural enemies," he said.

If scouting and reporting is lax, then the pest could pose a risk to the landscape plants as well as the nursery and bedding plant industry in East Texas, said Dr. Scott Ludwig, Extension integrated pest management specialist.

In the four counties Ludwig serves - Cherokee, Van Zandt, Smith and Henderson - annual wholesale receipts are about $300 million, Ludwig said.

If the pink hibiscus mealybug is found, Bogran said, avoid broad spectrum insecticides that may negatively affect beneficial insects, released or naturally occurring.

"Insecticidal soaps and horticultural oils are the best options when applications are needed, he said.

If necessary, prune off the most heavily infested (damaged) plants or plant parts, place in sealed bags and dispose of them, Bogran said.

"Avoid moving infested plants or plant material as it helps the spread of the pest to unaffected areas," he said.

Pink hibiscus mealybug colonies may be guarded by ants which feed on the honeydew and may protect them from their natural enemies.

"Fire ant control may be necessary for the success of any pest control," he said.

The Texas Department of Agriculture is working to release beneficial insects in the areas where infestations are confirmed, he said.

Ludwig emphasized that if homeowners suspect they have a mealybug infestation, it is to everyone's benefit, including their own, that they report it. The Texas Department of Agriculture will supply the beneficial insect control. They may or may not cut down the infested plants, he said. The release of the beneficial insects could save the homeowners' and neighbors' landscape plants.

"The main thing is that we have good biocontrol agents for this pest," Ludwig said. "Over 90 percent of control is typically achieved when the agents have been released in other areas. I don't see there being any negative impact on a homeowner for turning in a suspect infection. They're (the Texas Department of Agriculture) just going to confirm the infestation and work with homeowners to manage it."