Cooler weather ideal for mites

Univ. of Md. Extension entomologist Stanton Gill reports that cooler spring weather has helped broad mites and cyclamen mites to flourish. He said he sees most of the damage from these mites during April and May. Once temperatures in the greenhouse start to heat up the damage caused by the mites is reduced.
Gill said the small size of these makes it difficult to detect them before their feeding damage is evident on the plants. The mites hide in dark, moist areas within tender buds or deep within the flower.
Cyclamen mites have a broad host range and feed on cyclamen, dahlia, gloxinia, ivy, snapdragons, vinca, chrysanthemum, geranium, fuchsia, begonia and petunia. These mites prefer to feed in buds and young leaves. Leaves curl inward and develop a puckered appearance. Pit-like depressions can also form. Leaves may become brittle or appear streaked. Flowers can become shriveled and discolored. Flower buds may not open at all.
Broad mites also have a wide host range and feed on ageratum, begonia, cyclamen, dahlia, gerbera, gloxinia, hibiscus, ivy, jasmine, impatiens, New Guinea impatiens, lantana, marigold, snapdragon, verbena and zinnia. They can also infest vegetable transplants such as beans, peppers and tomatoes.
Broad mites feed on the underside of leaves. They inject a toxin from their saliva as they feed. Leaves become twisted, hardened and distorted with bronzed lower surfaces. Young terminal buds can be killed. Leaves frequently turn downward.
Gill said both broad and cyclamen mites are too small to be seen without the aid of a microscope. Regular inspection of crops for their feeding is needed.