The predatory mite Amblyseius andersoni eats many differentpest mites such as spider mite, gall mite, and russet mite. Main target pests are red spider mite (Tetranychus urticae), European red mite (Panonychus ulmi), apple rust mite (Aculus schlechtendali) and boxwood bud mite (Eriophyes canestrinii). Spider mites are present on a large number of host plants where they can cause a lot of damage resulting in discoloration of the leaves and formation of webs. Besides the aesthetic damage, spider mites also cause growth inhibition. Gall and russet mites are minuscule and barely visible with a regular magnifier lens. Russet mites cause a brown discoloration of the leaves and gall mites cause malformations. When noticing the damages, the pest mites are already present in large numbers.
A. andersoni does not only feed on harmful mites, but also on thrips, pollen, honeydew and fungi.

Typhlodromus (Amblyseius) potentillae or Amblyseius (Euseius) andersoni are the different names used to indicate this predatory mite. It is an indigenous species in Southern and Western Europe and is naturally present in several biotopes such as vineyards and orchards. The predatory mites become active at 6 °C - 8 °C, as most spider mites do. By introducing A. andersoni early it is not necessary to wait until the pest appear spontaneously to control it. Because A. andersoni is a polyphageous mite, it easily finds an alternative food source to maintain itself compared to predatory mites that prefer just one prey. Another advantage is that they can survive even in absence of prey and still prevent any possible outbreak. When the pest has been eradicated, A. andersoni-predatory mites can starve for a while, but still form a threat to other preys. When the prey of other predatory mites is gone their population immediately decreases considerably.

Biobest delivers A. andersoni in the following formulations:

Andersoni-System: The predatory mites are delivered per 10.000 pieces in practical 1 liter tubes. The composition of the carrier consists of bran and vermiculite. Depending on the crop and pest level disperse at least 20 to a maximum of 100 predatory mites per m².

Andersoni-Breeding-System: The predatory mites are released in the crop by means of breeding waterproof sachets. Each sachet contains a minimum of 250 A. andersoni predatory mites in a carrier of bran and mites as a food source. Over a period of several weeks thousands of predatory mites will progressively emerge from only one sachet via the pre-punched hole and graduallly spread throughout the crop. There is no need to open sachet. Hang 1 sachet every 2 meters in a row of plants. If necessary, repeat introduction after 6 weeks to maintain a continous presence of A. andersoni in the crop. NOTE: Introduction of Phytoseiulus persimilis in hot spots is a favorable addition.

The ideal storage temperature is 13 °C - 14 °C. At this temperature the mites stay in optimal condition for at least one week. It is nevertheless recommended to release them in the crop within 18 hours. Lower storage temperatures can have a negative influence on the conservation of A. andersoni.

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