Gall midge feltiella acarisuga fights many varieties of spider mites. The winged adult is able to detect colonies of spider mites over large distances. The larvae of feltiella can consume large quantities of spider mites and eggs, up to as many as five times the quantities consumed by phytoseiulus. The adult is a 2 mm. long, reddish brown midge with long legs. The shiny, translucent eggs are oblong shaped with a diameter of approximately 0.25 mm. The larvae grow from 0.2 mm. to 2 mm. and are visible in spider mite colonies.
Life cycle and relative effectiveness
A gall midge larvae needs large quantities of food to develop. The larvae are immobile, hence the adult lays its eggs primary in places with sufficient food supplies. Within one or two days the eggs hatch and the larvae, approximately 0.2 mm in size, starts their search for spider mites. Various stages are consumed. Unlike aphidoletes, feltiella pupates on the leaf. The white cocoons are visible along the veins of the leaves. Within seven days, depending on the climatic conditions, the adult will emerge. Feltiella is an indigenous insect that often occurs spontaneously in greenhouses during summertime.
Application and dose
A gall midge can be used in many different crops, especially in those where phytoseiulus is less effective. Usually a combination of feltiella and phytoseiulus is the best option. After all, the eggs of feltiella are only deposited in colonies. Light infestations are therefore uncomfortable for feltiella. During application avoid direct sunlight on the buckets and place them in (developing) spider mite colonies. Leave them in position for at least seven days. Light infestations: introduce two or three buckets per hectare every week. Heavy infestations: introduce seven to eight buckers per hectare every week
Storage and handling
Feltiella supplied in buckets, containing 250 pupae. Use as quickly as possible. Maximum storage time of two days at a temperature between 8°C – 10°C.