By Robin Koestoyo

FORT PIERCE, Fla.— Florida citrus and nursery growers need to develop proactive management plans for Lebbeck mealybug, an invasive pest that can cost the fruit and ornamental industry thousands of dollars in damages to fruit trees and landscaping plants.

A team of research scientists is working to prevent such scenarios with an early diagnostic kit to identify the invasive mealybug on trees and nursery plants. The insect is hard to detect and identify during its early life stage because it is so tiny that it is often concealed in small crevices in plants.

“Mealybugs are among the most common regulatory pests in the United States, especially in Florida,” said Nicole Quinn, assistant professor and research entomologist at the UF/IFAS Indian River Research and Education Center (IRREC) in Fort Pierce, Florida.

Quinn and a research team of mealybug experts won a grant from the Florida Nursery, Growers & Landscape Association to share their kit with nursery stakeholders and distribute the kits to nursery owners, managers, and growers. Quinn, Lance Osborne, an entomologist at the UF/IFAS Mid-Florida Research and Education Center in Apopka, Florida, and Muhammad “Zee” Ahmed, a research entomologist with the United States Department of Agriculture Agricultural Research (USDA-ARS) Horticultural Research Laboratory in Fort Pierce, work with a sense of urgency to teach agriculturalists how to use them in the fields and greenhouses.

“I applaud the researchers in their work to develop the Lebbeck mealybug diagnostic kit so rapidly,” said Ronald D. Cave, director of IRREC and Quinn’s immediate supervisor. “The team of entomologists has forgone efforts to seek a patent on the kit to prioritize immediate needs for the industry they serve and Florida’s economy.”

Quinn said, “Florida is vulnerable to invasive species, and we want to give the growers this tool before we have a problem that impacts the ability of our growers to export their fruit.”

The Lebbeck mealybug (Nipaecoccus viridis) is easy to miss when young. In citrus groves, a sign of an infestation is deformed fruit, often leading to high levels of fruit drop. “The diagnostic kit will help growers distinguish between the Lebbeck mealybug and other mealybugs, such as citrus mealybug, coconut mealybug, long-tailed mealybug, Madeira mealybug, papaya mealybug, pink hibiscus mealybug, solanum mealybug, and solenopsis mealybug,” Ahmed said. The Lebbeck mealybug is native to Southeast Asia, where it is called the spherical mealybug. “In ornamental plants such as oleander and jatropha, its heavy infestations are associated with leaf distortions, crinkling, and discoloration due to excessive feeding and reproduction,” said Ahmed. “In addition, it excretes sticky honeydew leading to the growth of black sooty mold on the leaf surfaces, which reduces the plant photosynthesis, growth, and ultimately its aesthetic values in the landscape,” Ahmed said.

“We have found a reagent that reacts with the mealybug and positively identifies a Lebbeck mealybug when it turns green,” said Ahmed. “The kit includes a dropper bottle with a reagent inside and a fabric that looks similar to a paper towel.”

The team will teach nursery growers to scout for the purplish-red young “crawler” mealybugs, crush them on a piece of kit paper, and then apply the dropper solution to the crushed mealybug body when placed on the kit paper.

“If the crushed body of a mealybug turns green—it’s a Lebbeck mealybug,” said Ahmed.

Ahmed developed the diagnostic kit along with a co-author, Lily Deeter, in an article published in the Journal of Applied Entomology and is collaborating with Quinn, Osborne, Christina Dorado, a research chemist with the USDA-ARS Horticultural Research Laboratory in Fort Pierce, and Lauren Diepenbrock, assistant professor and research entomologist at the UF/IFAS Citrus Research & Education Center (CREC), Lake Alfred to enhance the scope of this kit.

“Mealybug species are almost impossible to differentiate at the crawler stage in the field,” said Ahmed. “The diagnostic kit will be the first in the world to identify the Lebbeck mealybug in the field so that growers can distinguish it from other common mealybugs during pest scouting,” said Ahmed.

Osborne, an expert in integrated pest management, recommends producers get the kit, test new materials before planting them into their larger crops area and destroy the new Lebbeck mealybug-infested plants.

“This is important to ornamental growers because it allows them to identify and manage infested plant materials. If producers can identify the mealybug, they can dispose of the infested plants without having to quarantine their entire field or crop,” Osborne said.

Quinn said invasive plants and insects are prevalent in Florida. But, scientists, citizen scientists, and gardeners are becoming increasingly aware of invasive plants and insects and how to manage them. The increased awareness powers more community-wide pest management strategies and public interest to join the fight against invasive species.

“Growers, gardeners, and others who move plant material from one location to another can help prevent Lebbeck mealybug spread and infestation by being aware of what is in their plants,” said Quinn. “We can all play an important role in protecting Florida’s landscapes from invasive species,” said Quinn.

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The mission of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) is to develop knowledge relevant to agricultural, human, and natural resources and to make that knowledge available to sustain and enhance the quality of human life. With more than a dozen research facilities, 67 county Extension offices, and award-winning students and faculty in the U.F. College of Agricultural and Life Sciences, UF/IFAS brings science-based solutions to the state’s agricultural and natural resources industries, and all Florida residents.

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