Ants are common in vineyards and include both pests and beneficial species. Of the pest ants, Argentine ants (Linepithema humile) are the most common and problematic in coastal California. They establish mutualistic relationships with sap-feeding insects; protecting these insects from natural enemies while feeding on honeydew, a sugary food source. This renders biological control less effective. Targeting Argentine ants (often with bait) is therefore key to integrated control programs for sap-feeding insects, such as aphids and mealybugs.
More information: UCIPM: Ants
Left: Argentine ants carrying ant larvae
Information adapted from materials by UCIPM, UCCE Napa, Bettiga et al. 2013. Grape Pest Management. Third edition. University of California, Agriculture and Natural Resources, Richmond, CA, USA.
Video: Malcolm Hobbs