Rainfall Sets Stage For Several Nuisance Pests

Springtails

Springtails are tiny wingless insects that can flip into the air, giving them the appearance of tiny fleas. They would go completely unnoticed except that hundreds of them can accumulate on surfaces like a small, dusty gray carpet that moves.

Figure 1. Springtail close-up (Photo: C. Judy)

Figure 1. Springtail close-up (Photo: C. Judy)

Most springtails live in rich soil or leaf litter, under bark or decaying wood, or in association with fungi. Many are scavengers, feeding on decaying plants, fungi, molds, or algae. Springtails become abundant among wet leaves, soil, and plant material along a house foundation or sidewalks, where they can be a temporary annoyance. They also can occur around floor drains, in damp basements, and in crawl spaces. Masses of these insects can be swept up and discarded.

Springtails do not survive in dry conditions. Any steps to improve ventilation and promote drying are the best long term solutions. Removal of accumulations of wet leaves or other organic matter will eliminate breeding sites. Aerosol household insecticides can be used to treat infestations but will provide only temporary relief if the favorable conditions are not corrected.

Midges and Gnats

Midges and gnats, such as fungus gnats (Figure 2) and March flies (Figure 3), are common names for a large number of small, non-biting flies. Many species look like mosquitoes and may form annoying swarms or clouds in the air, but they do not bite. Immature stages develop in water in pools, containers, ponds, clogged rain gutters, or in some cases, wet soil or seepage areas. Most feed on living or decaying plant matter and are an important part of aquatic food chains.

Figure 2. Fungus gnat (Photo: Lee Townsend, UK)

Figure 2. Fungus gnat (Photo: Lee Townsend, UK)

 

Figure 3. March fly (Photo: Lee Townsend, UK)

Figure 3. March fly (Photo: Lee Townsend, UK)

There are no good alternatives for control of the adults; however, they only live for a few days. If necessary, resting accumulations of these insects can be treated with an aerosol spray containing pyrethrins. These are impractical for treating anything other than small areas. These products only kill insects that are directly hit by spray particles; there is no lasting or residual effect.

Clover Mites and Winter Grain Mites

Clover mites and winter grain mites are active in some lawns. Clover mites are very small, reddish-brown creatures (Figure4) that appear only as moving dark spots to the naked eye. Winter grain mites have dark black bodies with long red legs.

Figure 4. Clover mite (Photo: Lee Townsend, UK)

Figure 4. Clover mite (Photo: Lee Townsend, UK)

Sheer numbers of either mite, plus the resulting red-brown stain left behind if they are crushed, make them unwelcome visitors. The red stains are not blood; they are the mite’s body pigments. These mites are not blood feeders and will not harm people or pets, nor will they infest household products. Once inside a home or building, they will soon die.

Clover mites and winter grain mites feed on turf grasses or weeds. They can be especially abundant in the heavy, succulent growth of well-fertilized lawns. They usually enter a home around windows or doors, so they can be seen crawling along sills or thresholds. The mites can crawl up outside walls and may enter the buildings at upper levels.

Lawn mites are a temporary nuisance; they appear suddenly and then are gone. A soapy rag or wet sponge can be used to clean mites off of surfaces. Wipe carefully to avoid crushing the mites and causing stains. The crevice tool of a vacuum cleaner may also be used to pick up mites. Rely on non-chemical control indoors. Do not apply insecticides to kitchen counters or other interior surfaces.

There is an increased potential for invasion when grass extends up to a structure’s foundation. A plant bed or open area will provide a barrier that will stop many mites and provide a long term solution to persistent problems. Avoid applying excess fertilizer to lawns; this creates situations that are ideal for mites to increase to tremendous numbers.

Mites seen on the outside of buildings can be killed with a direct spray of an insecticidal soap. This treatment will not provide any residual control. A spray of a labeled synthetic pyrethroid insecticide along the outside walls and extending about 10 feet out from the foundation may provide some relief.

 

By Lee Townsend, Extension Entomologist

 

Posted in General Pests, Lawn & Turf