Cheese mites are small insects which are just visible to the naked eye. When they attack cheese they will first be detected as a brown powder on the surface of the cheese or in small cracks or breaks in the paraffin. When cheese mites are permitted to act on the cheese for a long time, they borrow into the cheese, leaving behind them the characteristic accumulation of brown powder, which consists of dead mites, living mites, cheese debris and excreta. This brown powder has a characteristic sharp, pungent odor.
Photo attribution link: By United States Department of Agriculture () [Public domain], via Wikimedia Commons
Cheese mites have soft, hairy cream white bodies with 8 hairless legs and adults grow up to an approximate 0.5mm in length.
The cheese mite favors warm, moist conditions and eggs mature in 10 days at room temperatures. Females can lay up to 900 eggs in a lifetime at a rate of 20 – 30 a day. Adult cheese mites can live for up to 60 – 70 days.
With a preference for old cheese to young cheese, these mites also feed on nuts, dried eggs, fruit, flour and tobacco. Cheese mites are capable of contaminating foods to cause skin or gut irritation. Temperatures of about 60°F are very favorable for their growth. As the temperature of the curing room is decreased, the activity of these mites decreases. They will grow at temperatures between 60°F and 90°F.