A few tiny heroes may help fight Florida's long-running battle against citrus greening disease. Researchers with the UF Institute of Food and Agricultural Sciences (UF/IFAS) have found three commercially available insect species that devour the eggs of the Asian citrus psyllid, the pest responsible for spreading Huanglongbing (HLB), the disease that has severely damaged the state's citrus groves for two decades.
For growers who have watched orchards wither and yields collapse, the discovery feels like a rare bright spot. These natural predators could become a new line of defense in a fight that has stretched on for years and cost billions. This is particularly true for organic growers who have limited options to control the psyllid, said Xavier Martini, a UF/IFAS associate professor of entomology.
© UF Institute of Food and Agricultural Sciences (UF/IFAS)Lacewing larvae eating ACP eggs. Photos: Romain Exilien
Those who grow citrus at home also might deploy the predatory bugs to battle psyllids.
Researchers need to see how these bugs perform outside the lab in real-world conditions. In the past, scientists have tested the ability of predatory bugs to eat nymph and adult psyllids. This was the first experiment on psyllid eggs, Martini said.
Romain Exilien, a post-doctoral researcher at the North Florida Research and Education Center (NFREC), led the new study, supported with funding from the USDA National Institute of Food and Agriculture.
The research shows three of the four predatory bugs eat psyllid eggs at high rates.
© UF Institute of Food and Agricultural Sciences (UF/IFAS)Mealybug destroyer searching ACP eggs.
Scientists studied the minute pirate bug, the green lacewing larva, a ladybeetle named mealybug destroyer and the predatory mite Ambly swirskii. All except Ambly swirskii significantly reduced the egg numbers.
Over two days, minute pirate bugs consumed 67 eggs, whereas lacewing larvae ate 111 and mealybug destroyer 153. At 93 and 97 percent, green lacewing and mealybug destroyer ate the most eggs.
"Homeowners are the main target here," said Martini, who serves as Exilien's supervisor at NFREC. "I am confident that our lab experiment will transfer pretty well to a single tree in a garden with minimal to no insecticide spray. Homeowners are interested in biological control of all bugs, but particularly psyllids."
© UF Institute of Food and Agricultural Sciences (UF/IFAS)Minute pirate bug eating ACP eggs.
Jawwad Qureshi, an associate professor of entomology at the Southwest Florida Research and Education Center and a co-author on the current study, said growers will appreciate these findings.
"The findings on their egg consumption are encouraging," Qureshi said. "These findings indicate that targeting Asian citrus psyllid eggs with lacewings or mealybug destroyers may substantially enhance sustainable psyllid management and support long-term HLB mitigation in citrus groves."
For more information:
Brad Buck
UF/IFAS
Tel: +1 (656) 347-8422
[email protected]
www.ifas.ufl.edu
