and ticks belong in the phylum Chelicerata, class Arachnida, order Acarina.
is the commonest species (see above) of mite in foodstuffs; it has reddish/pinkish
legs. Flour mites can live in almost any type of flour or in fodder and,
not least important, in stores of seed or corn. They are also to be found
on old cheese. A single female can lay up to 500-800 eggs in her lifetime
at a rate of 20-30 a day.
hatching the life cycle consists of a larval stage, two so-called nymphal
stages and the adult stage, which at 25°C is reached in three weeks.
These mites can go through their life cycle at a temperature as low as
0-4°C, but they do require adequate humidity, and will not thrive
if the relative humidity is less than 65% as they will desiccate. The
entire life cycle may take only nine to eleven days to complete under
the optimal conditions of 90% humidity and 77° F. The life cycle is
completed in seventeen days at 64-71°F, and twenty-eight days at 50-60°
mites are able to withstand periods where the conditions are unfavourable.
After the second nymphal stage they may pass into what is known as hypopus
stage which is a diapause form, in which they are almost immobile and
very resistant to desiccation. In the hypopus stage,
the body wall hardens and suckers appear on the underside. These suckers
allow the mite to attach to insects and other animals for dispersal. The
eggs and especially the hypopuses appear to be more tolerant of insecticides
than other juveniles or adults; and they may be the primary stage responsible
for resurgences in mite populations after chemical control appeared to
have been successful.
or grain mites are pale, pearly or greyish white, with legs varying in
colour from pale yellow to reddish-brown. Each leg has one claw at the
end. As with all mites, they are smooth, wingless, soft-bodied creatures.
The males are from 0.013 to 0.017 inch long, and the female is from 0.014
to 0.026 inch. The males have enlarged forelegs which bear a thick spine
on the ventral side. These two characters can be used to separate Acarus
sp. from other genera. Juvenile mites are similar in appearance to the
adults. The first or larval stage has only six legs. However, when they
moult into the nymphal stage, they have eight legs like the adults. Mite
eggs are oval, smooth, white, and are 0.12 mm long
there is any doubt as to whether flour is infested with mites it is only
necessary to spread a little out on a table and leave it for quarter of
an hour. If the mites are present the surface of the flour will become
uneven as the mites start to wander about.
infested foodstuffs acquire a sickly sweet smell and a taste which renders
them unsuitable for human consumption. Heavily infested products are definitely
injurious and should be discarded. Heavily infested grain and feed that
has become tainted and unpalatable as animal feed. When fed infested commodity,
small companion animals (e.g., dogs) can show reduced feed intake, diarrhoea,
inflammation of the small intestine, and impaired growth. Pigs that consume
mite-infested feed have their live-weight gain, feed:gain ratio, and nitrogen
retention markedly reduced.
only effective method of controlling mites is to ensure that the foodstuff
in question is stored as dry and as cool as possible. Failing this fumigation
will have to be considered. Because of the higher tolerance of mite eggs
to fumigation, the concentration of gas introduced will need to be fifty
percent greater than that for insect control. Fumigants are highly toxic,
and technical knowledge is required for their proper use. A qualified,
licensed pesticide applicator should be contacted to perform the fumigation.