Aphids & ants, Dominica

October 2008. A question about controlling root aphids on vegetables that are being attended by ants. Attempts to control the ants have failed, so what can be done? Specifically, it was asked whether instead of concentrating on reducing the ant population, it would be better to reduce the population of aphids. Any treatment must not be damaging to the environment.

A supplementary question asked about people’s experiences with parasitic nematodes (so far not approved for importation into Dominica).

A member suggested the use of spinosad which is registered for ant control and is an organic product. It has been found to be an excellent option for control of some thrips and caterpillar pests as well. There is information on ant control using spinosad at http://msucares.com/insects/fireants/organic.html.

It was still thought best to target the ants, because the ants will also be feeding on other food sources besides the honeydew secretions from the aphids. Aphid, mealybug and soft scale control should begin with ant control. Once the ants are controlled, natural predators and parasites will deal with these sap sucking insects.