Description
Amblyseius cucumeris is a species of predatory mite that feeds on immature stages of thrips. It also feeds on pollen, two-spotted spider mites and other species of pest mites. Cucumeris adults are pear-shaped, tan colored mites, less than .5mm long. Eggs are round, transparent and .14mm in diameter.
Target Pest
Western Flower Thrips (Frankliniella occidentalis), Onion Thrips (Thrips tabaci), Cyclamen Mites, Bamboo Mites and Broad Mites.
Life Cycle
A complete life cycle takes 10-12 days at 68F. Amblyseius cucumeris populations have somewhat more females than males (64% females).
Females lay 1-3 eggs per day for an average of 35 eggs over their lifetime. Eggs are laid on leaf hairs along the veins on the lower surface of leaves, and hatch in about 3 days. Newly hatched larvae do not feed until they molt at 2 days old. They feed for another 7 days before becoming adults. Adults live for up to 30 days and eat an average of 1 thrips/day.
Although in northern climates, outdoor populations of Amblyseius cucumeris diapause in response to short days, the Amblyseius cucumeris now sold for greenhouse use are non-diapausing strains and may be used year round.
Use in Biological Control
Amblyseius cucumeris is mainly used to control Western Flower Thrips in greenhouse vegetable and flower crops. For more information see our Thrips Tech Sheet). Optimum conditions are 68-77F with relative humidity 66-70%.
Monitoring Tips
Use a 10-15 X hand lens to inspect for mites, which are most often found along veins on the underside of leaves or inside mature flowers.
Product Information
Amblyseius cucumeris adults and immatures are shipped mixed with a bran carrier. They are available in two types of packaging.
- Bulk cartons, containing 10,000 - 50,000 predators. The contents are gently shaken onto leaves throughout the greenhouse or planced on the rock wool block or growing media in contact with the plant stem. Upon receipt active predators should be visible at the top of the container at room temperature.
- Slow release sachets, containing approximately 1/8 cup (30ml) of carrier with predators and a food source. The bags act as miniature breeding units and are hung on plants throughout the greenhouse. Over four weeks, each bag can produce over 1,000 predators under good conditions.
Introduction Rates
Relatively high introduction rates are required because thrips can reproduce nearly twice as fast as A. cucumeris and A. cucumeris only feeds on immature thrips, not adults.
General Introduction Rates
- 10-100 A. cucumeris/plant, weekly, as needed.
Using the Bulk Product
- Greenhouse peppers-10 A. cucumeris /plant. One introduction is sufficient early in the growing season if pollen is available as an alternate food source.
- Greenhouse cucumbers - 25 A. cucumeris/plant by placing a small pile of media touching the base of the stem as soon as they are planted in the greenhouse. On larger plants use 50-100 A. cucumeris /plant, weekly, until the percentage of leaves with predators is greater than that with thrips.
- Greenhouse tomatoes - 25 A. cucumeris/plant, weekly for two weeks, when thrips are detected.
Using Slow Release Sachets
- Greenhouse cucumbers - 1 sachet/plant in infested areas.
- Interior plantscapes - 1 sachet/large plant
Hang sachets within 10 inches of the growing point on greenhouse crops, ensuring good contact with the stem and leaves. Sachets should not be exposed to direct sunlight or overhead watering. Do not tear open pre-punched bags as they will become too dry.
Establishment of Amblyseius cucumeris requires 4-8 weeks, so it should be applied before thrips problems develop. Because A. cucumeris feed only on immature thrips stages, a decrease in future adult thrips populations will not occur for about 3 weeks. Adult thrips have a long life cycle (+30 days) so adults will continue to cause damage and adults should be controlled by releases of Orius or by using sticky traps.
For Best Results
Where P. persimilis is being used for control of spider mite, avoid heavy applications of A. cucumeris. A. cucumeris feeds on spider mite eggs, which may limit the food supply for immature P. persimilis and reduce their effectiveness.
Use A. cucumeris along with other thrips predators such as Orius on flowering plant and Stratiolaelaps to control thrips pupae in the growth media.
Using Chemicals
Some insecticides and fungicides can be used with A. cucumeris. Contact Sound Horticulture for more information. Use of any water-based sprays with spreader stickers will kill some predators and wash them off the leaves.
There are no selective pesticides that will kill thrips and not harm A. cucumeris, however, insecticidal soap sprays may be used in hot spots and will not leave harmful residues.