Association between ants (Hymenoptera: Formicidae) and the vine mealybug (Hemiptera: Pseudococcidae) in table-grape...

The vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) is a key pest of grapevine in the Mediterranean Basin. Some honeydew collecting ant species are known to increase mealybug populations in other grape-growing regions. However, there is scarce information on either the ant species present in Mediterranean vineyards or their impact on mealybugs. We conducted a study in four commercial vineyards in Eastern Spain in order to i) identify the ant species foraging on the vine canopies, ii) study the association among ant activity, vine mealybug abundance and fruit damage, and iii) test a novel method for ant management, distracting ants from guarding vine mealybugs by providing sugar dispensers.

We recorded three ant species native to the Mediterranean foraging on the vine canopies: Lasius grandis (Forel), Pheidole pallidula (Nylander) and Plagiolepis schmitzii (Forel). The mean percentage of damaged fruits per vine was positively correlated with the number of vine mealybugs captured in traps placed at the trunk. We detected a positive but weak relationship between ant activity, vine mealybug abundance and fruit damage. The provisioning of sugar dispensers reduced the number of ants foraging on the vines by 23.4% although this reduction was not statistically significant. Vine mealybug abundance was significantly reduced (72%) after sugar provisioning.

Our results suggest that the ant species native to vineyards in eastern Spain induce population increases of the vine mealybug. Moreover, the provisioning of sugars can be a valuable tool for ant management and mealybug control. © 2017 Society of Chemical Industry.