Even after the mite’s death its faecal particles
remain in the home, and the mite’s disintegrating body parts are still allergenic and easily airborne.
Although no environment is free of dust mites, there are specific steps you can take to reduce the number of these
creatures in your home. Many of these emanate from old wives’ tales, but have their basis in fact:
Mattresses, box springs and pillows should be encased in non-allergenic, plastic-zipped casings. The zips should be
covered with adhesive tape. Wipe with a damp cloth or vacuum weekly. If there is more than one bed in a room, each
mattress should be encased. If bunk beds are used, the allergic child should sleep on the top bunk. Avoid using canopy
beds.
Use washable blankets, spreads and polyester or dacron pillows. Avoid feather pillows, down or padded comforters, wool
blankets and chenille spreads. Wash all bedding frequently in hot water (over 60 degrees centigrade). Don’t use an
economy wash as mites survive in warm water, and you just end up with clean mites!
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Ants
Understanding Ant Music
The ability to communicate through infochemical means, including pheromones, is at its highest among insects which live
in homogeneous communities – social insects. The ant in particular is distinguishable by its numerous exocrine glands
and the various chemicals it secretes as it relays information among its groups.
The largest ants have eyes located about 5mm from the ground whilst the smallest have eyes less than 1mm above the
ground and are unable to see beyond anything more than 5mm tall. Eyesight then, is not their strongest point. Ants
evolved from bees and they have developed acute olfactory senses which enable them to forage for food even in the
darkest situations. The ant senses environmental chemicals such as odours or non-volatile matter through physical
contact via its antennae. It then reacts according to the information the chemicals convey.
Chemical signals for species recognition
Insect species consist entirely of males and females with a male and female from each species reproducing. Sex
pheromones facilitate mating encounters however, how does an insect ascertain that the potential mate belongs to the
same species?
Dr Ryohei Yamaoka, of the Kyoto Institute of Technology has evaluated the important role infochemicals play in individual
identification among ants by observing their behaviour in their fascinating world. The team sampled cuticular waxes,
particularly hydrocarbons, from more than 500 species of insects including ants. They discovered that the composition of
these substances was species specific for all the insects sampled. They also discovered what happens when two ants
from different species meet and fight savagely. Only when the antennae of one ant actually touches its opponent’s body
will the fighting begin. No matter how closely the two pass, unless the antennae of one touches the body of the other, no
fighting will occur. Ants do not recognise their opponents by vision, but by non-volatile chemicals on their bodies and they
also seem to confirm membership of the same species by detecting like-for-like hydrocarbons in the same way.
Different species of ants can live together
In order to live together, different species must change their previous recognition of their cohabitants as belonging to
different species. Slave maker ants (Polyergus samurai) invade nests where so-called hill black ants (Formica japonica) or
forest black ants (Formica sp.) live, attack and steal pupae and cocoons from them and bring their booty back to their
own nest. They attend to the pupae and cocoons until they hatch as well as nurturing the slave maker queens’ eggs. In
the nest, slave maker ants avoid productive activity. They walk about lazily prompting slave ants to feed them.
Dr Yamaoka’s team sampled cuticular hydrocarbons from two species of ants which live harmoniously in the same nest
as previously mentioned and discovered that slave maker ants can barely synthesize hydrocarbons natural to their own
species and receive the cuticular hydrocarbons they possess from slave ants through bodily contact. Accordingly, slave
maker ants take on the same hydrocarbons as those of their slave ants and are thus chemically camouflaged, rendering
them recognisable as cohabitants by their slave ants.
Signals which allow ants to identify mates from the same nest
The chemical discrimination ability of the ant is so great that it can distinguish not only ants of different species, but ants
from different nests (colonies). Cohabitants from the same nest are generally offspring
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