Anderline aa

Amblyseius andersoni

Spider mites and Rust / Russet mites

Product guide 

Product description

Amblyseius andersoni is a predatory mite that can be used in the control of a range of mite pests. This predatory mite is ideal for vegetables, hardy ornamentals and fruit crops, controlling red or two-spotted spider mite, fruit-tree red spider mite, and russet mites.

It is active at lower temperatures than other predatory mites, which means that it can be introduced much earlier in the growing season than some other predators. It is available in the Mini sachet with a hook or the water-resistant Gemini sachet that will tolerate irrigation or rain, so can be used in outdoor crops and over-head irrigated protected crops. Packed as 100 Gemini sachets per box, 200 Mini sachets per box or as loose material in bottles, tubes or bags containing 10,000, 25,000 or 125,000 predatory mites.

Predatory mite

  • Treats many types of spider mite and other mite pests
  • For protected or outdoor crops
  • Long lasting Controlled Release Sachet (CRS) maintains protection
  • Ideal for fruit trees and soft fruit crops
  • Ideal for deciduous hardy ornamentals
  • Tolerant of temperatures 6ºC-40ºC 

Used for

Pests Crops
Broad Mite and Cyclamen Mite (Polyphagotarsonemus latus and Phytonemus pallidus)  Aubergine
Spider Mite Two Spot or Red - (Tetranychus urticae and Tetranychus cinnabarinus) Blueberries
Tomato Russet/Rust mite (Aculops lycopersici/ Eriophyidae) Cucumber
Cut Flowers
Ornamental pot plants
* Trials at East Malling in the UK indicate control of Raspberry Leaf and Bud mite. Strawberry
* Trials in California USA indicate good control of Lewis Mite  Eotetranychus lewisi  in  strawberries Tomato

General Information

Amblyseius andersoni occurs naturally throughout Europe, including the UK and the Netherlands, and in North America. It is primarily found in areas of grape and apple production, but also in soft fruit, peaches, deciduous ornamentals and conifers.

They prey on spider mites of various species, but also feed on Thrips and russet mites. They may enter diapause in late summer, but are active from early in the season, as well as tolerating high temperatures, provided the atmosphere is suitably humid.

Instructions for use

Gemini sachets:
Lift each sachet from the box, pinch the join so that the printed face is outwards and drop the sachet over the crop wire, branch or leaf stalk.

Mini sachets:

  • Hang from crop wire or plan
  • Do not hang adjacent to heating pipes
  • Duration of sachet activity is 6 weeks, though longer-lasting control may be evident if the mites establish in the crop

Gemini sachets:

Use at one per 2 - 4 metres of crop row.

Mini sachets:

Use at one per 2 metres of crop row.

Shaker Tube:

  • 1 litre containing 25,000 mites
  • Shake small quantities of Anderline onto the crop near to flowers
  • Introduce Anderline early in the crop/pest cycle to protect against pest build up

    Storage and transport

    • Keep out of direct sunlight
    • Transport and store at 10-15ºC
    • Use within 18 hours of receipt

    Anderline aa is a product containing the predatory mite Amblyseius andersoni Phytoseiidae, Acari, which is widespread in Europe and North America. It is a predator of various species of phytophagous mite, including Tetranychus spp, Panonychus spp and Eriophyidae.

    It is supplied as units of 25,000 mites in our patented Gemini sachets. A box holds 100 sachets, each containing a breeding colony of 250 predators at the time of packing. The sachet formulation ensures that mites continue to breed, and are released onto the crop, over a period of several weeks.

    Gemini sachets are water resistant, and can be used in crops with overhead irrigation, or those grown outside.

    This is the only predatory mite for spider mite control which is available in a controlled release formulation. Anderline aa is also available as loose material in bulk bags or cardboard tubes.


    General information

    How does it work?

    Amblyseius andersoni is a predatory mite which feeds on many types of small arthropod prey and pollen. It is widely reported in the literature as a predator of spider mites on fruit crops such as apples, peaches, grapes and raspberries. Recent research at WUR (PPO) in the Netherlands identified A. andersoni as a promising predator for use on ornamental plants grown for gardens.

    Adult female mites lay single eggs onto leaf hairs, and these eggs hatch after 2-3 days to give larvae. As with other mites in the same family, these moult to produce protonymphs and then deutonymphs as they grow. All mobile stages are predatory, and will feed on eggs, juveniles and adults of spider mites. They are also able to feed on Eriophyid mites, commonly known as Rust or Russet Mites, which are tiny, worm like mites which can cause major damage on some crops.

    As days become shorter and temperatures decrease in early autumn the mites will enter diapause, a state in which they can successfully survive winter conditions. They are reported to become active again as early as January, but this will be dependent upon ambient temperature and food availability.

    Amblyseius andersoni can be produced in a bran-based medium using stored product mites as food. Until recently, only Amblyseius cucumeris had been reared in this way, and only Amblyseius cucumeris had been sold in sachets as a Controlled Release System (CRS). This system essentially places a breeding colony of predators onto the plant, even before the target pest is present. This breeding colony is contained within a small paper sachet, which is carefully designed to maintain that colony in good condition. Predatory mites continue to emerge from the sachets over a period of several weeks, and in much higher numbers than can be achieved by a single release of a loose product.

    A. andersoni now joins A. cucumeris as a CRS product, and is ideal for preventive control of spider mites on a number of crops. It is available in our unique Gemini sachets. This is the first spider mite predator to become available in a controlled release formulation.

    Gemini sachets are a patented development of Syngenta Bioline. Each sachet consists of a pair of compartments containing breeding colonies of predatory mites. The key advantages of this sachet design are:

    • It is resistant to water, and so maintains the breeding population in good condition
    • It is suitable for use in outdoor crops
    • Predatory mites are released onto the crop over several weeks, and can be introduced before the prey is present
    • Release rates are higher than can be achieved with other spider mite predators, such as Phytoseiulus persimilis and Amblyseius californicus


    Amblyseius andersoni has also been tested as a predator of Eriophyid mites, including the Tomato Rust Mite Aculops lycopersici. In tests against this pest, A. andersoni has shown an ability to spread over the tomato plants and to breed on a diet of Aculops lycopersici. Initial trials in Switzerland, using rates of 100 A. andersoni per plant as a single release of loose product, confirmed this interest. The sachet formulation releases much larger numbers of mites over several weeks. In commercial trials using sachets, growers have reported that the damage caused by Aculops was markedly reduced, that infested plants remained healthy, and that the spread of infestation was reduced or prevented.

    When and where should you use it?

    Apply the sachets to any convenient location on the plant, such as a leaf petiole, twig or small branch. In crops grown against supports, or trained along wires, the sachets can be placed on these structures, but should always be shaded from direct sunlight.

    In tomato crops, where the product is used against Aculops lycopersici, place the sachets as high as possible on the plant. There are two reasons for doing this:-

    • The lower leaves of tomato plants are routinely removed, and with them so are sachets placed low on the plant. Placing the sachets as high as possible maintains them on the plant for longer.
    • Aculops lycopersici form large populations which move up the stem of the plant as a rust-coloured mass. Some mites will be found up to 20 cms ahead of this ‘wave-front’. Placing the sachets above this mass will allow the predators to feed on the advancing mites before they cause damage: placing sachets lower down means that the predators are approaching this mass from below, and are only able to remove pest mites after the damage has been caused.


    How should you use it?

    For best results, apply the sachets when pest mite numbers are low. The predatory mites will then be able to feed on small colonies of pest mites and prevent them growing and causing major damage. Curative use has also been successful on some crops such as cucumbers and some species of hardy ornamental plants.

    Individual Gemini sachets are packed flat into boxes in units of 100. To use the sachets, pick each sachet up with a finger and thumb at the central line. The twin compartments of the sachet should hang down from this central line, forming an inverted ‘V’ shape. Make sure that the printed face of the sachet is facing outwards, and that the un-printed face, on which the emergence holes are situated, is facing inwards. This ensures that water cannot enter the sachet.

    Alternatively for indoor crops Anderline aa is also available in Mini Sachets with a hook attached. They should be introduced at 2 metre spacing along the crop row.

    When should you not use it?

    Anderline is intended as a preventive treatment for spider mite and other mite pests, which is best used before pest populations have reached high levels. If pest mite populations are very high, and major damage is visible on the crop, use an alternative treatment such as an acaricide prior to the introduction of Anderline.

    What will it do?

    Used as directed, Anderline will control or limit spider mite populations and significantly reduce pest damage. On some crops no other treatment is necessary. In other crops the additional use of Phytoseiulus persimilis or acaricides to control pest mite outbreaks may be necessary.

    What will it not do, and what are the control options?

    Amblyseius andersoni will not give control of whitefly, thrips or aphids. It is a predatory mite which is intended for control of mite pests.

    Where pest populations are high at the time of release, control may be slow to occur and damage to the crop will continue. In such cases it is preferable to reduce the initial pest populations with a local application of an acaricide such as Vertimec®, Dynamec® or Avid® (abamectin). Predators can be released within one week except in very low light levels, when degradation of surface residues of the acaricide is slower.

    Small pest populations will always be present around the area of visible damage, and spot treatments with acaricides or predatory mites may miss these. Always introduce sachets to areas surrounding those with obvious damage, as well as to visibly infested areas.

    For outbreaks of spider mite in situations where acaricides are not acceptable, use high rate applications of the predatory mite Phytoseiulus persimilis or Amblyseius californicus. The predatory beetle Stethorus punctillum may also be available in some countries.

    Anderline aa has been developed for use on hardy ornamental plants and fruit crops. The range of hardy ornamental plants is very large, and leaf structure is very variable, with some such as Buddleia davidii having softly hairy leaves, whilst others such as Choysia ternata have glossy, aromatic leaves. It is not possible to test the performance of the product on all possible species and varieties, or in all growing conditions.
    Chemical compatibility

    Amblyseius andersoni is reported to be one of the first predatory mites to invade fruit crops after insecticide treatments are reduced. Strains which are resistant to pyrethroid insecticides are reported from Italy.

    The strain which is in commercial use is not specifically selected for resistance, so always use caution when applying crop protection products. The structure of the sachet will protect the colony of mites from many treatments, so even if mites on the foliage are killed, fresh mites will emerge from the sachets to replace these.

      How to use Anderline aa (Amblyseius andersoni)

      • Keep the product in the shade until use
      • Open the box of sachets in the crop
      • Lift each sachet out by the centre ‘hinge’ and allow the compartments to hang
        down to form a tent, with the printed side uppermost
      • Place each sachet over a leaf petiole or crop wire
      • The weight of the two compartments will hold the sachet in place



      • Use as soon as possible after receipt
      • Keep at 10°C - 15°C until ready to use
      • Do not refrigerate