Detecting storage mites in organic farming

Mites such as the plum mite (left) and the flour mite (right) can only be seen with a microscope (here magnified 60 times).

Description of the storage pests

Mites are eight-legged arachnids ranging in size from 0.3 to 0.7 millimeters, which have various appearances when viewed under a microscope. The frequently occurring flour mite for example, is oval, shiny white with faintly purple legs that Mildew mite differentiated by longer hairs at the end of the abdomen.

Mite infestation can be identified without a microscope on various symptoms recognize. Products appear to be covered with a light to brownish layer of dust. They take on a sweet to minty odor and a bitter taste and become crumbly. More severe infestation (from 500 mites per kilogram of grain) causes an acrid sweetish odor, the stored product is destroyed to the point of unusability.

A mite can move about 25 millimeters in one minute move around. If infestation is suspected, a sample of product can be spread thinly on a dark surface, for example, with a sieve, and look for dust-grain-sized bright spots that move or rumple the product. After a few minutes, the surface becomes rough and increasingly crumbly due to the movement of the mites.

Similar pests

dust mitesreach a size of up to 2 millimeters and move quickly and jerkily. The insects and their movement can be seen with the naked eye, unlike mites. coatings on the products. Rarely to light dust like the mites.

pest pattern and pest effect in moist food

Mites infest food stored in moist conditions, flour stored for a longer period of time, or products that have become moist due to previous infestation by insects harmful to the food supply. In addition to flour and cereals, mites occur on stored bran, semolina, oatmeal, pasta, fish meal, oleaginous fruits, dried fruit, dried fodder plants and the like.

Chronic yellowing can occur on stored grain with a grain water content above 14 percent. In addition to active spreading, flour mites can also be introduced by insects, birds and bats. They owe their establishment on food items in part to tube fungi that release gaseous ammonia, which promotes population buildup and contributes to the spread of tube fungi.

Grains and produce are partially or completely inedible as well as partially useless as food. This comes from contamination with larval skins and feces and the excretion of Poisons (toxins), as well as bacteria and fungi transmissible by mites. The consumption of infested products can cause intestinal diseases, rashes and asthma, in farm animals there is a risk of miscarriage, in horses colic. Infested products can still be added to feed for fattening pigs after treatment. More information on how to deal with infested products. The seedling is destroyed. flour loses its ability to go. In the event of contact with moldy products can allergic reactions occur. A mass infestation of mites can act like a lubricant, for example between stacks of paper bags, causing them to collapse.

Biology and habitat

Organic farming recognizing storage mites

In temperate climates, the flour mite is probably the best known of the storage mites. Photo: JKI

In temperate climates, the globally widespread Flour mite Probably the best known of the storage mites. The female lays up to 1000 eggs during her life of up to 100 days, from which the larvae hatch after about a week. The larva causes a relatively large feeding damage within one week before it develops into a mature mite via various nymph stages; the total development period is about 2 to 6 weeks. Under optimal conditions, however, the population can multiply within just one week. Drought and lack of food lead to the development of permanent nymphs (hypopes). The fashion mite can lay up to 350 eggs in warm temperatures, the development period is 3 weeks to 3 months. it does not form a permanent hyphae stage and is therefore more sensitive to unfavorable environmental conditions

Mealy mites need a high humidity of 75 to 85 percent; modern mites can also occur at 65 percent relative humidity, but they need more than 13.5 percent grain moisture in cereals or more than 9 percent grain moisture in oil fruits to infest them; for the plum mite, 60 percent relative humidity at 15 percent grain moisture is sufficient. They can hibernate in appropriately moist, frost-free storage facilities; individual developmental stages survive even mild winter temperatures. Adult mites survive in warmth nests at temperatures of up to 50 degrees. During the warm season the development accelerates. Often leads to mass infestation.