Most citrus tree problems in home gardens can be solved by pruning the trees to allow better air flow and by controlling ants. Ants collect the honeydew produced by Asian citrus psyllid nymphs, mealybugs and cottony cushion scale to feed their colonies (Figure 1). To protect this honeydew food source, ants guard the pest insects from natural predators and parasites that help control pest populations.
To improve biological control, home gardeners should keep ants out of trees and shrubs by banding the trunks with sticky substances such as Tanglefoot or by using ant baits. Young trunks should be protected from possible injury by wrapping the trunk with a collar of duct tape or fabric tree wrap and coating this with the sticky material. The sticky material must be checked every week or two and stirred with a stick to prevent the material from becoming covered with debris that ants can cross. Branches must be pruned to prevent ants from using them to gain access to the tree. Placing ant stakes or liquid baits at the base of the tree is an effective way and less labor intensive way to control ants.