Unlike
most other bugs, the bed bug is wingless. When it has not recently
fed the body is paper thin, and almost red brown. So far as is
known bed bugs came originally from Asia, but they have now spread to
all parts of the world. They were well known in ancient times
in the Mediterranean area. As they require a warm, dry climate
they did not spread to northern regions until buildings started to be
heated, but when this did happen they soon became very abundant. They
are now less common and are largely kept under control by modern insecticides.
Bedbugs belong to the
family of true bugs known as Cimicidae. Members of this family are small,
oval, flat, hard-bodied, flightless insects in which the wings are absent
or reduced to stubs. When unfed, the common bedbug adult is 1/4 to 3/8
inch in length and brownish in color. After feeding, the body elongates
and widens and the color changes to dull red. This apparent change is
quite striking and may cause the observer to believe that two different
species of insects are present. Bedbug nymphs resemble the adults but
are smaller and have a pale yellow coloration after molting. The nymphs
undergo five molts, becoming successively larger after each molt. Since
some bedbug nymphs may feed more successfully than others, development
time may vary greatly even among nymphs from the same generation. For
this reason, both adults and nymphs will usually be present throughout
the year.
Bedbug eggs are elongate,
about 1/32 inch long (see below), white in color, and have a distinct
cap at one end. The eggs are laid singly or in clusters and are cemented
to wood, fabrics, or other surfaces in places where the bugs hide.
Bed
bugs only search for blood donors when they are actually hungry.
In the intervals between meals they spend their time in suitable hiding
places in the vicinity of the bed. These may be crevices in the
timber, joints in the bed, behind the headboard, beneath loose carpeting,
behind pictures, behind wallpaper, in plug sockets, light switches,
etc. When hungry, bed bugs come out from their retreat and start
to search. Their senses are not capable of guiding them to a distant
blood donor, but at distances of 5 - 10cm they will be attracted
by the body warmth of the victim. Bed bugs can crawl up a wall
and can also walk upside down on rough ceilings, but if they are not
skilled they often fall down. This is the basis of stories that
bed bugs, having observed that their victim had placed the legs of the
bed in dishes of water, crawled up the wall and across the ceiling and
let themselves fall on to the poor sleeping body. However the
bed bug is not as crafty as this.
In
the course of about 10 minutes an adult bed bug can suck up to 7 times
its own weight in blood. It then retreats to its hiding place,
where it digests, mates and lays eggs until it is hungry again.
The eggs are laid in the hiding place, where they are attached to the
substrate. A female lays 200 - 500 eggs at
the rate of 3 or 4 eggs per day,
but the actual number depends upon the temperature and other external
factors. They do not lay at all at temperatures below 10C. At
temperatures above 70° Fahrenheit, egg hatch occurs in 6 to 17 days.
Hatching may take up to 28 days at lower temperatures. Development to
the adult stage may occur in as little as one or two months, but usually
takes longer. A given bedbug individual usually does not feed every
night, but at intervals of a few days to a week. Newly-hatched nymphs
will feed as soon as possible, then usually feed once between each molt.
If left undisturbed, a bedbug can obtain a full blood meal in 3 to 5
minutes. Bedbugs can live for 4 to 12 months without feeding. The bugs
will survive longer without a meal at lower temperatures than at higher
temperatures.
Bed
bugs have an incomplete metamorphosis, remember they don't pupate,
young bed bugs are like small versions of the adult. They moult
5 times during their development and at each stage they require a
blood feed. When fully mature the adult is 4 - 5mm long about
the same as a ladybird..!
If
the infestation is particularly heavy, then a slight minty smell is
apparent when the area is first entered, some people say it smells
like old dirty laundry.....depends on the nose I suppose...
!
This
chap is in the course of having lunch
Bedbugs may be found in
many situations, including homes, hotels, poultry houses, around laboratory
animals or small caged pets, or near bird and bat nests and roosts.
Bedbugs often find their way into the luggage of travelers and may be
transported and spread in this manner. If the occupants of a home or
apartment infested with bedbugs move out, the bugs may migrate to other
nearby dwellings. Similarly, they may occasionally enter homes after
a bird or bat control program has eliminated their normal hosts, and
are sometimes unknowingly carried into the home from poultry houses.
The Fly Bug (Reduvius personatus),
an assassin bug, is known to feed upon bedbugs (see below). Presence
of this insect in the home may be indicative of bedbug infestations,
although this is not always the case since these assassin bugs may enter
homes anyway.
Indications
of bed bugs in the initial stages are not obvious (when there are only
one or two about), you may notice when you change the bed that there
are a few blood spots on the sheets, and you think to yourself that
you probably scratched yourself during the night (or the wife punched
you on the nose), but this isn't the case as it will be blood from the
site on your body where the bed bug sucked your blood. As the infestation
increases, you would probably see live insects and at the main harbourage
area there would be dark excreta marks (consisting of faeces and partially
digested blood). Also in the main area would be cast nymphal skins (see
picture below), which shows the skins and excreta marks.
Treatment:
OK..
so how do we treat a bed bug problem...well, you really need to be employing
a professional person who knows what they are doing. In turn they
need to looking for all potential places where they might be hiding
(I have found them in light fittings, light switches, power boxes, inside
wooden legs of bunk beds, cracks in plaster, etc) in addition rooms
either side of the infestation and also above and below need treating
as well to help provide a barrier and to try and contain the problem.
By the use of residual sprays and dusting powders and also another visit
after about 2 weeks the problem will normally be brought under control.
But...don't
forget that bed bugs can be easily transported via luggage, washing,
furniture etc., in other words do not move anything out of the infested
area without it first being treated. In the case of large infestations
such as the wing of a hotel or hospital, then there could be a place
for using fumigation. This is a treatment using gas which not
only kills the adults but the eggs as well, but there are lots of Health
and Safety involved in this sort of operation.
Two
of the pictures above are copyright to Richard C. Russell
Sydney
University
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