By L.M. Diepenbrock
Insect and mite 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 insect and mite biology in relation to tree phenology, plans can be developed to protect fruit and maintain productive citrus trees.
Populations of many of highly problematic pests (Asian citrus psyllids, citrus leafminers and lebbeck mealybugs) generally increase with flush/new growth development, so targeting peak flush periods can help keep their populations from exploding. For early spring applications, be sure to check the label for use in relation to bloom for pollinator protection. The 2020-21 Florida Citrus Production Guide: Asian Citrus Psyllid Table 2 summarizes materials recommended for use during this period. These pests will need to be managed throughout the year, though the extent of management depends on the intended fruit market.
Rust mite and citrus 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 scouting and management recommendations can be found here.
For growers in North Florida, Florida red scale has become problematic. See Danielle Sprague and Xavier Martini’s article in the January 2021 Cold Hardy Citrus Connection for scouting recommendations to time management appropriately. Chemical recommendations can be found in the Soft Bodied Insects Attacking Fruit and Foliage chapter of the production guide.
More information on managing pest in North Florida citrus can be found here.
Thrips can be a challenge, especially for fresh market producers. Flower thrips cause damage during bloom if populations are increasing and 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 orchid thrips can be found here. Recently, chilli thrips have been found in some growing conditions, damaging both leaves and fruit. While we do not have specific management recommendations for this pest in citrus yet, insecticide active ingredients (spinetoram, cyantraniliprole and acetamiprid) that are used to successfully manage this pest in strawberries are also available in citrus.
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 the pest’s biology.
If you need help making your management decisions, consult the 2020-21 Florida Citrus Production Guide and the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) citrus agents.
L.M. Diepenbrock is an assistant professor at the UF/IFAS Citrus Research and Education Center in Lake Alfred.