Data from: Cover crops dismantle keystone ant/aphid mutualisms to enhance insect pest suppression and weed biocontrol

Cover crops are multifunctional tools that mitigate environmental impacts
of agriculture, enhance resilience to weather extremes, and suppress weeds
and arthropod pests. Cover crops provide non-crop food and habitat
resources that attract natural enemies of pests, but their outcomes for
pest management are less clear in regions where keystone mutualisms
between red imported fire ants and aphids dominate. Here, we manipulate
ant exclusion treatments and cover crop that vary in food/habitat
resources treatments (living mulches and terminated cover crops), and
examine responses of ants, aphids, and other herbivores and predators in a
cotton agroecosystem. Living mulches reduced both ants and aphids in the
crop canopy by 97% and 93%, respectively, relative to bare soil
treatments, and terminated cover crops reduced them as well by a lesser
degree (~50%). Non-aphid herbivores occurred in low densities system-wide,
and increased in living mulches, while native predators had variable
responses to cover crops and ant exclusion. Cover crops had no effect on
prey removal in the crop canopy, but living mulches tripled rates of weed
seed biocontrol relative to bare soils. Cover crops elicited a shift in
fire ant foraging from cotton foliage downward to the soil-surface,
preventing competitive exclusion by keystone ant/aphid mutualists that
dominate crop monocultures. Cover crops altered the system-wide impacts of
fire ants: reducing ecosystem disservices (i.e. aphid tending), and
enhancing ecosystem services (i.e. weed seed biocontrol). These results
provide incentives for cover crop adoption as a regenerative practice in
large-scale commercial agriculture.