The latest Arizona Vegetable Integrated Pest Management Update from the University of Arizona (UA) Cooperative Extension in Yuma, Ariz., released Sept. 21, 2011.

Insecticide pre-mixtures and insect management

By John Palumbo, UA Research Scientist and Extension Specialist

Insecticide pre-mixed products are currently available for the management of insect pests on desert vegetable and melon crops. These products offer growers and pest control advisers (PCAs) the convenience of two different active ingredients in the same formulated product.

Examples of pre-mixtures include Durivo, Vetica, and Brigadier. These pre-mix products contain combinations of active ingredients that PCAs have been using for many years (e.g., thiamethoxam, bifenthrin), as well as active ingredients recently registered (e.g., chlorantraniliprole and flubendiamide). In some cases, the pre-mixed products are available at reduced prices relative to tank mixing two individual products.

Users should consider which active ingredients are included in the ‘in-can’ mixtures, and at what rates these active ingredients are applied relative to the pre-mixed formulation. This is important.

First, the rates used for the pre-mixture should be within the recommended rates of the individual active ingredients necessary to control a particular insect(s). This may force PCAs to use high rates of the pre-mixture to achieve adequate control of multiple pests. Traditionally, this has been achieved through tank mixtures of two or more products; each at the recommended rates.

Second, although the active ingredients found in pre-mixes are of different chemical classes, one or both of the active ingredients may be the same as other products currently used in the same field.

PCAs should be careful not to inadvertently expose insect populations to the same chemical class (mode of action) by making repeated applications with products with the same mode of action. This is how insecticide resistance quickly develops.

To avoid this, be aware of the active ingredients in all products applied. For example, the pre-mixtures Durivo, Voliam Xpress, Voliam Flexi, and Vetica contain active ingredients with the same mode of action as Coragen and Synapse.

For more information on pre-mixtures, the active ingredients, and rate equivalencies, review this document: Insecticide Pre-Mixtures for AZ Vegetables and Melons.

Contact Palumbo: (928) 782-3836 or jpalumbo@ag.arizona.edu.