[Mallis Excerpt] "Spring Fever"

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October 17, 2003

Springtails (Collembola) are very small insects, generally measuring 0.04 to 0.08 inch (1 to 2 mm) in length, that occasionally invade homes and are particularly prominent in the basement, bathrooms and the kitchen of structures. Springtail infestations in buildings are usually associated with dampness, organic debris and mold. Springtails can be a problem in newly constructed buildings because of damp building materials and wet plaster. As the building dries, the springtails will die or leave.

Springtails do no damage but their presence (often in large numbers) — and the fact that they jump — can be upsetting. Most reports of hundreds or thousands of tiny, dark, jumping insects can be correctly diagnosed as springtails.

Springtails occur in various shapes and sizes; however, they all have one key identifying character. Each springtail has an appendage, called the furcula, that folds from the abdomen’s tip back underneath to the front and is held in place by a clasplike structure. When the springtail is disturbed, it releases the furcula, which propels the insect through the air and away from danger. The species found in structures usually range in color from whitish to dark gray. They do not bite, lack wings and undergo a simple metamorphosis where the young resemble the adults except for size, color and sexual maturity.

These insects belong to the order Collembola, are widely distributed and are among the most common soil insects. The most recent reference lists this order to have 812 species found in 83 genera in the North America north of Mexico. They commonly occur inside and underneath potted plants and also in vegetable matter such as decaying plant bulbs. Buildings with constant high humidity may literally be overrun with thousands of springtails. In one case in western Pennsylvania, an unknown species of springtails infested the floor of a living room by the thousands after heavy rains in September. Two days later, when the weather was dry, only three springtails were seen in the house. On another occasion in central Pennsylvania, springtails were present in enormous numbers on snow covering a lawn and invaded the porch of the house. Such cases prompt the nickname "snow fleas." Springtails are attracted to lights and may pass under lighted doorways at night. Presence of plants and mulch under windows causes a build-up of large outdoor populations.

Springtails move ordinarily by short runs, separated by periods of rest. Springtails, for the most part, feed on algae, fungi, fungus spores, pollen and decaying vegetable matter. Some species attack living plants and a number are scavengers on dead animal matter. As mentioned previously, springtails can withstand low temperatures and, in Arctic zones, are occasionally so numerous that they almost cover the snow. Sira buski Lubbock and S. platani (Nic.) occur in the home and, due to their protective scales, can exist in a drier environment than most springtails.

Springtails do not transmit human disease. Entomobrya nivalis (worldwide) and Entomobry tenuicauda (Australasian) reportedly cause an itching type of dermatitis in humans. Orchesella albosa (North American and European) has been recorded as infesting, without dermatitis, the head and pubic areas of humans. Entomobryaatrocincta (worldwide) is a pest of dried milk powder.

MANAGEMENT OF SPRINGTAILS. Springtails found inside a structure suggest the presence of excess moisture conditions, such as a water leak or excessively high humidity. Springtails may also enter a structure seeking moisture when their outside habitat becomes too dry. Simply drying out the affected area will often eliminate springtails. It has been reported that springtail infestations are on the increase in New Jersey.

The following is recommended: (1) repair water leaks and other moisture problems; (2) remove wet, moldy wood or other moldy items; (3) use a fan or dehumidifier to increase air circulation and dry out the area; (4) allow the soil in potted plants to dry out between waterings; and (5) reduce mulch and other materials outside around the foundation.

TREATMENT. If springtails are moving in from outside, a perimeter treatment may be necessary. A perimeter treatment should be applied to the building foundation and several feet from the building in those areas where these insects are found. Treatment of exterior cracks at foundation level also may be beneficial.

The author is manager of technical services for Terminix International, Memphis, Tenn. He can be reached via e-mail at shedges@pctonline.com.