Efficacy of two methodologies to exclude ants from citrus canopies

Abstract: Ants have a positive effect on populations of California red scale, Aonidiellaaurantii (Maskell), in citrus. Previous studies have shown that the presence of Argentine ant,Linepithema humile (Mayr), as well as the complex of native Mediterranean ant species,Pheidole pallidula (Nylander) and Lasius grandis Forel, increase the densities of A. aurantiiat harvest. Sticky barriers have been successfully used to exclude these ant species fromcitrus canopies. However, this method is too laborious to be applied on large areas. In thisstudy, the efficacy of an insecticidal paint based on chlorpyrifos and pyriproxyfen in a microencapsulatedformulation (Inesfly IGR FITO©) to exclude ants was evaluated. Its efficacywas compared to sticky barriers (Tangle-Trap® Insect Trap Coating, Tanglefoot). Our fieldresults, showed that a single application of Inesfly IGR FITO© in April excluded L. humile,L. grandis and P. pallidula from citrus canopies along the season. Furthermore, the exclusionof L. grandis and P. pallidula significantly reduced the percentage of downgraded fruit bypresence of A. aurantii.