Whiteflies Provide Honeydew to Camponotus ants Without Receiving Reciprocal Favor

Abstract

The notion that tending ants provide protection to honeydew-producing hemipterans is widely accepted. Nevertheless, there have been debates about whether or not this protection can always disrupt the biological control of hemipterans. Although various hemipteran species interact with tending ants, most studies have focused on the mutualism between ants and aphids. Woolly whitefly Aleurothrixus floccosus (Maskell) is an important pest of citrus whose nymphs are frequently tended by ants such as Camponotus. However, it is unknown whether or not ants in this genus can disrupt biological control of woolly whitefly by protecting this pest’s nymphs from natural enemies. We investigated the impact of Camponotus ants on the biological control of woolly whitefly in the field by excluding or allowing the access of ants to whitefly nymph colonies in different tangerine trees. Furthermore, in a laboratory study we also assessed the behavior of Camponotus ants in response to woolly whitefly’s common predator cues (visual and scent). In summary, this field-laboratory study suggests that there is no mutualism between tending Camponotus ants and the whitefly A. floccosus; rather it indicates commensalism as an alternative interaction. Interactions as this may provide more benefits for the host plant, whereby Camponotus ants can reduce sooty mold by removing honeydew from the leaves and favor pest biological control by leaving the whiteflies unprotected.