Flour/Grain Mite (Acarus siro)

An important pest of dried and stored food, occurring often in grain stores, animal feed and flour mills, bakeries, cheese stores and dried fruit handling facilities. Musty or minty odours build up in food when infestations are heavy.

Identification:
Adult mites 0.4 – 0.5mm in length, pale or greyish white in colour, with legs varying from pale yellow to reddish-brown. The first or larval stage has only six legs. However, when they moult into the nymphal stage, they have eight legs like the adults. Mainly found in stored food, bulk grain and animal feed.

Biology:
Female grain mites may lay up to 800 eggs, which are deposited on the surface of food material at the rate of approximately twenty to thirty per day. The eggs may be deposited singly or scattered at random over the food material. The entire life cycle may take from between 9 and 28 days depending on the heat and humidity of food storage areas.

Control:
Infestations in domestic or food storage situations can usually be traced back to a cereal source. Since these mites can infest so many types of grain products, inspect thoroughly. There may be several infested products, discard any food that is infested. Infested areas should be thoroughly vacuumed paying particular attention to cracks and crevices, contents of the vacuum cleaner should be disposed of in an outside bin. Store new food products in sealed glass or plastic containers. Proper ventilation also is necessary to reduce humid environments. After cleaning, treat the infested areas using a residual insecticide labeled for crawling insect to ensure that all adult beetles and larvae have been killed.

Products to control Flour/Grain Mites: