Large tub of 250 cocoons. Adult gall-midges, which can fly, actively search for spider mite colonies and deposit eggs next to the spider mites. It takes one week for the eggs to develop to mature larvae. Once hatched, the larvae will devour large quantities of spider mite. They are active in spring and autumn when light levels are lower and will be active from 15 degrees.
The Feltiella acarisuga is supplied in a tub of cocoons. Adult female midges emerge from the cocoons, mate inside the tub then fly off to lay their eggs amongst spider mite infestations. The treatment is more expensive than Phytoseiulus but if you have a known problem on a sizeable crop then one tub is excellent value as they will establish and breed just from one bottle.
Like most midges they are fine in moist conditions and for that reason the midge is recommended for introducing at the beginning of the season, before the red spider mite gets out of control. However they do need some spider mite to feed on, so they only use early if you know you had a problem last year and you fear that spider mite eggs and young may have overwintered. This control is not recommended for the hot dry conditions of mid summer.