Photo by Allan Busuulwa, UF/IFAS graduate student
By Lauren Diepenbrock
Pest management is a year-round challenge in Florida citrus. With the warm climate, pests are at the ready as soon as plant resources are available to them. With knowledge of invertebrate biology in relation to tree phenology, growers can develop plans to protect fruit and maintain productive citrus trees.
HIGHLY PROBLEMATIC PESTS
Populations of some highly problematic pests (e.g., Asian citrus psyllid and citrus leafminer) generally increase with flush/new growth development. Therefore, targeting peak flush periods can help keep their populations from exploding.
The first major population increase of lebbeck mealybug generally occurs with initial fruit setting. Damage from feeding at this stage of fruit development will cause high rates of fruit drop. Protecting developing fruit is key to protecting the crop. For early spring applications, be sure to check the label for use in relation to bloom for pollinator protection. These pests will need to be managed throughout the year, though the extent of management depends on the intended fruit market.
RUST MITES
Rust mite damage to fruit can be minimized by targeted management in late spring (April/May), when populations first start to develop. Keeping mite levels low while fruit are in the early stages of development can prevent high levels of damage. Information for rust mite scouting and management recommendations can be found here.
THRIPS
Thrips can be a challenge, especially for fresh market producers. Flower thrips cause damage during bloom if populations are increasing. This pest should be managed prior to bloom to reduce flower abortion. Orchid and greenhouse thrips cause rind blemishing where they feed on developing fruit. Information on scouting and treatment of thrips can be found here.
Chilli thrips have emerged as a management challenge in screenhouse production. Research into their management is ongoing. Preliminary data suggest that managing non-crop hosts including weeds and other flowering trees can reduce the local population and subsequent migration into citrus under protective screen or nurseries.
ROOT WEEVILS
Root weevils are present in various life stages throughout the year. Because the primary damage from root weevils occurs underground, it can be hard to time management actions appropriately. The Citrus Root Weevil chapter of the Florida Citrus Production Guide describes the life cycles of the root weevils that attack citrus and explains management options that take advantage of their biology.
SNAILS
In recent years, Bulimulis bonarienses, commonly referred to as the peanut snail or ghost snail, has been wreaking havoc in citrus groves by clogging irrigation and defoliating young trees within individual protective covers. While University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers are still learning the seasonal activity patterns of this pest and evaluating management options, they have found that abamectin, which is used for several other pests in citrus, can also have impacts on these snails. In product screening assays, Agri-Mek SC (abamectin 8.0%) used at the maximum labeled rate for citrus had a 100% mortality rate if applied during periods of snail activity (i.e., when snails are mobile, exposed or partially exposed from their shells).
If you need help making pest management decisions, consult the Florida Citrus Production Guide and the UF/IFAS citrus agents.
Lauren Diepenbrock is an assistant professor at the UF/IFAS Citrus Research and Education Center in Lake Alfred.
Share this Post
Sponsored Content