Amblyseius Cucumeris

Cucumeris is the preferred predator for thrips control. They are tan colored mites found on the underside of leaves along the viens or inside mature flowers.These mites are most effective at preventing thrips and spider mites build-up when applied early in the growing season at the first sign of thrips. 

Neoseiulus cucumeris is a predatory mite used to suppress immature thrips, two-spotted spider mites, cyclamen (or strawberry) mites (Phytonemus pallidus), broad mites (Polyphagotarsonemus latus) and mites of the genus Schizotetranychus in ornamental, fruit and market garden crops.

Life Cycle

A complete life cycle takes 10-12 days.

• 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. They hatch in about 3 days.
• Newly hatched larvae do not feed until they moult 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.

NATURAL CONTROL OF THRIPS

The life cycle of Cucumeris begins with small white eggs that can be seen attached to leaf hairs along veins on the lower leaf surface. At 68 degrees F eggs hatch in about 3 days into nonfeeding larvae that molt to nymphs after about 2 days. The 2 nymphal stages which last 7 days, as well as the adult stage which lasts up to 30 days feed on immature stages of thrips. The adult female can lay up to 35 eggs in her lifetime. Adults can eat an average of 1 thrips per day and also feed on two-spotted mites and their eggs.

A. cucumeris works best at 54 to 86-F and 70 to 80% relative humidity. The mite is generally located on the underside of leaves along veins or inside flowers. Both nymphal and adult stages feed on western flower thrips. Adults feed on 1 thrips per day. However, they only attack young (1st instar) western flower thrips. This is because large thrips strike the predatory mite with their abdomens. In addition, thrips excrete a wet substance that covers predatory mites, the mites then spend time cleaning themselves instead of attacking thrips. The mite will also feed on pollen and two spotted spider mite eggs. A. cucumeris will enter into a resting stage (diapause) in late fall in response to short daylengths and low temperatures 

Establishment of Cucumeris requires 3-4 weeks, so they should be applied before thrip problems develop. Because cucumeris feed on immature thrip stages a decrease in adult thrip populations will not occur for about 3 weeks.

One method of releasing A. cucumeris into greenhouses or interiorscapes is by lightly shaking them onto plants from containers, which have between 10,000 to 25,000 predatory mites mixed with bran and vermiculite. It is beneficial to lightly mist the plants before release, so the mites do not fall off. Another method involves placing slow-release sachet bags, containing approximately 300 mites, among the crop. Mites will emerge from these bags and migrate directly into the crop. These bags last approximately 3 to 4 weeks sometimes longer. 

A. cucumeris is most effective when plant leaves are touching and thrips numbers are low. The success of this mite depends on the availability of alternative food sources such as pollen, and moderate to high relative humidities. Plants with hairy leaves can reduce the performance of A. cucumeris, because it is harder for the mite to move around on the plant. In addition, low relative humidities can severely affect egg hatch, as drier air will cause the small eggs to desiccate.