Individual study: Impacts of Argentine ants on mealybugs and their natural enemies in California's coastal vineyards
Daane K.M., Sime K.R., Fallon J. & Cooper M.L. (2007) Impacts of Argentine ants on mealybugs and their natural enemies in California's coastal vineyards. Ecological Entomology, 32, 583-596
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Exclude ants that protect pests
A randomised, replicated, controlled study in 1998-1999 in California, USA (Daane et al. 2007) found greater parasitism of mealybugs Pseudococcus spp. by parasitoid wasps (Encyrtidae) in grapevines Vitis vinifera with vs. grapevines without ant barriers (21-68% vs. 10-11% parasitised, respectively) in the Central Coast region. There was no effect in the North Coast region (0.00-0.02% vs. 0.004-0.005%). Fewer mealybug destroyers Cryptolaemus montrouzieri (introduced before the study) occurred in vines with vs. without ant barriers (0.07-0.09 vs. 0.29-0.31 mealybug destroyers/vine) in the Central Coast. The same effect occurred in the North Coast in 1999 but not 1998. Lacewing (Chrysopidae) numbers were unaffected in both regions (0.08-0.24 vs. 0.05-0.20 lacewings/vine). Fewer obscure mealybugs Pseudococcus viburni occurred in vines with vs. without ant barriers in the Central Coast (12-59 vs. 129-303 mealybugs/vine, respectively) and grape mealybugs Pseudococcus maritimus were similarly affected in the North Coast (6-28 vs. 54-69 mealybugs). Fewer Argentine ants Linepithema humile occurred in vines with barriers (0.0-0.9 ants/2 minutes/vine) vs. vines without barriers (25-39 ants). Barriers were made by stripping bark from vine trunks and covering the exposed wood with duct tape coated in Tanglefoot Pest Barrier (re-applied when necessary). Three vineyards across two regions were studied, with six replicates/site.