- Latin Name: Penthaleus major
- Latin Family Name: Penthaleidae
- Common Name: Winter Grain Mite
- Other Names: Blue Oat Mite
Origin:
Possibly native to North America.
Biology:
This mite can be a serious pest in lawns, pastures and other areas where grasses are grown throughout the cool season. There usually will be two generations each year, beginning with mites emerging from eggs laid in the soil that have passed the summer months in the soil. These first mites emerge in the fall and populations peak in mid-winter, with new eggs deposited. The second generation emerges from these eggs and these populations peak in late spring, gradually disappearing as the weather gets warmer. The mites are active at night and on cloudy days, moving under plant materials or into the soil on sunny days. The visible damage is to the foliage, but the mites may also move down to feed on the crowns, and at this point are more likely to kill the grass plants.
Identification:
This tiny mite is about 1 mm long and has a characteristic bluish gray body and pink-orange legs. In addition, under high magnification it can be seen that the anus is located on top of the end of the abdomen. Damage from the mites occurs from fall until the following spring and causes grasses that are attacked to take on a silvery appearance due to loss of chlorophyll in the blades.
Characteristics Important to Control:
The mites do best where soils are not disturbed, as this affects the eggs in the soil. Tilling the soil can reduce the number of surviving eggs and mites. Crop rotation to alternate the grasses with broadleaf crops also will affect the mite survival. For managed turf a labeled insecticide may also be effective in killing the mites.
