Biological Pest Control and Integrated Pest Management

Andersoni for Spider Mite Control

Amblyseius andersoni adultsThis predatory mite is beige in color and less than 1 mm in size. Amblyseius andersoni is a predatory mite that is a good biological control and natural enemy of many types of small arthropod prey like spider mites and pollen. It is widely reported as a predator of twospotted spider mites on heavily infested plants and fruit crops such as apples, peaches, grapes, and raspberries.This predatory mite eats many different mite species. They control spider mite, gall mite, and russet mite. The main target pests are spider mites (Tetranychus spp.), European (or citrus) red mite (Panonychus spp.), and Eriophyid mites, including the tomato rust (or russet) mite Aculops lycopersici.

Lifestyle

Adult female mites lay single eggs onto leaf hairs, and these eggs hatch after 2-3 days into larvae. All mobile stages are predatory, and they will feed on spider mite eggs, juveniles, and even adult spider mites. As temperatures decrease and days become shorter, in early autumn, these beneficial insects will enter into a diapause so they can successfully survive winter conditions. They are reported to become active again as early as January, but that depends on temperatures and the available of food like spider mites.

Benefits

Amblyseius andersoni can be used indoors and outdoors on a wide range of ornamental plants and other host plants. They are natural enemies of spider mites and other mite pests and can treat them without the use of chemical control. They have a wide temperature tolerance of 43ºF – 104ºF. Amblyseius andersoni is reported to be one of the first predatory mites to invade fruit crops after insecticide treatments are reduced. These mites can also survive on young larvae of thrips, flower pollen, sugary excretions from pests, and fungi, so they can be introduced before the prey like spider mites are present. 

They are available in loose shaker tubes and breeding sachets. The sachets are resistant to water so the breeding population of mites remain in good condition. The sachets can provide a release of mites over several weeks.

Drawbacks

Amblyseius andersoni is intended as a preventative treatment for spider mites and other pest mite infestations. It is best used before pest populations have reached high levels.

Scouting

Uninfested and damage/webbing-free new growth is a good sign. So, is empty webbing in interiorscapes and some greenhouses, or is webbing missing outdoors (if it was there, to begin with)? Unless your scouting is really top-notch, you’ll probably miss most of the predators present on the leaves. However, if you see some agile-looking mites running quickly across the leaf’s undersurface, they are probably predators.

Advisories

For best results, apply the A. andersoni when the number of pests like spider mites is low. The mites will then be able to feed on small colonies of mites and prevent them from growing and causing major spider mite damage. It is better to use A. andersoni together with other specialized predatory agents. Avoid exposing the sachets to direct sunlight.

Usages

This predator works well on spider mites, both inside protected crops and outside in ornamental crops, fruit trees, horticulture, nurseries, and seedbeds.

Release rates

Sachets: use one per every 6-10 Sq. feet of canopyShaker tube: 2 to 5 predator mites per square feet

In trees: 1 sachet/tree

Purchase