CLOVER MITES - Pest Control - Online Resources - Environmental Health & Safety
Clover Mites: Identification, Biology, and Control
Introduction
Clover mites are related to spiders and ticks, rather than insects. These extremely tiny mites are normally found outdoors, feeding on clover, grasses and other plants. Clover mites do not bite man and they do not transmit disease. Their red color is not due to blood but is a red pigment that will stain paper and other objects if mites are crushed. Clover mites may occur in large numbers indoors with the change of seasons in early spring and late summer. They are often found running around rapidly and erratically in warmer parts of a room. After a few days almost all of these mites will desiccate and die.
Interesting Facts about Clover Mites
- Males are unknown, females deposit only unfertilized eggs. This makes it possible to produce a large number of eggs rapidly and without mating.
- The red mite color is not due to blood, it is a red pigment that will stain paper and walls if the mites are crushed.
- Large numbers of mites feeding on grass will turn the grass brown.
Identification
This red pigmented very tiny mite (1/30th of an inch) is frequently seen running around inside of buildings. After heavy rains, excessive heat, or changes in the season, large numbers of these mites may accidentally enter buildings where they become a nuisance.
Individual mites are bright red with white stiff hairs that need high magnification to be seen. They leave behind a red stain or smear when crushed; the stain is not blood but rather a red pigment. Clover mites have eight legs; the first pair is longer than the rest and is often held forward.
Biology
In the spring, clover mite females lay eggs in cracks in concrete foundations, cracks and crevices of buildings, under sidings, and on the underside of bark at the base of the trees. Their eggs hatch above 40°F and below 86°F. Males are unknown and all eggs are therefore unfertilized.
After eggs hatch, the newly emerged immature clover mites move to feed on plant juices, molt, and pass through two nymphal stages. Approximately 30 days are required to complete a generation outdoors. One generation is completed during the spring or early summer months and another in the early fall.
Clover mites in the egg stage may either hibernate (overwinter) or become dormant during the summer under tree bark, in cracks of fence posts and foundation walls, under sheathing of buildings or in other dry protected sites, during adverse weather conditions.
Control
Clover mites are extremely difficult to control. Since clover mites are so tiny, they can easily enter buildings through cracks in the foundation, around window sills, under doors and under portable air conditioners and other locations. In some cases, a very careful caulking of the window frame can significantly reduce the number of mites that can come inside. Keeping clover, grass, moss and other vegetation away from the building foundation may also help. A perimeter of crushed stone may help to discourage mites from climbing up the building walls.
Understanding that these mites do not bite, do not transmit disease and are really just a nuisance will help to reduce any anxiety caused by seeing large numbers indoors. Vacuuming will reduce active mites but remember to toss out the bag’s contents or the mites may escape back into the room.
