New Knowledge on Lebbeck Mealybug Can Aid Control

Lebbeck mealybug populations are not tied to flush production, entomologist Lauren Diepenbrock reported recently. The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) assistant professor also noted:

• The majority of the lebbeck mealybug population is in the juvenile stage, which is highly susceptible to most pesticides throughout the year.
• A systemic chemistry applied prior to fruit set can protect developing fruit.

Diepenbrock sampled lebbeck mealybug populations in commercial citrus groves in Central Florida. Analysis of the seasonal trapping data provided easily observable trends. Based on these trends, she offers the following initial recommendations:

First, mealybug populations are not tied to flush cycles, so their management cannot be planned around peaks in flush production.

Second, the pest population is more likely tied to climatic variables than citrus tree phenology. She added that the availability of resources like food and shelter always support insect populations. “Both of these are readily available in groves,” Diepenbrock noted. “However, without true winter periods in Florida, timing populations to temperature is not clear-cut. We see populations growing during fruit set, which is also the time at which fruit are most vulnerable to damage from their feeding. While not quantified, growers that have known populations of lebbeck mealybug and who apply Movento prior to fruit set have reported less fruit drop and visible damage from the mealybug.”

The lebbeck mealybug population is largely composed of crawlers and immatures throughout the year, Diepenbrock noted. “These two life stages are susceptible to most chemistries and even many adjuvants, suggesting that chemistries applied for other pests including Asian citrus psyllid, citrus leafminer, diaprepes and rust mites throughout the remainder of the fruit production period should reduce the overall impact of lebbeck mealybug by reducing the number surviving to reproductive maturity. This strategy should work for juice production; however, increased management will be required for fresh fruit production.”

Source: UF/IFAS