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Fleas
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| You are viewing results 1 to 13 of 13 |
 Adult fleas are 1 -
8mm long and brownish in colour. The fleas body is laterally compressed (i.e.
flat), and covered with backward-directed bristles, they are wingless
and have small or no visible eyes. Fleas piercing mouth parts and
muscular legs - the hind ones being adapted for jumping - are
distinguishing features.
Adult fleas live exclusively as
parasites of warm-blooded animals, especially mammals, although birds
may also be attacked. While they show a certain degree of host
preference, fleas will feed on other animals in the absence of the
normal host. In fact, they tend to be more nest-specific than
host-specific, for while adult fleas may feed on the blood of a variety of animals, the larvae require more precise conditions which are
associated with the habitats and nesting habits of the hosts than the
characteristics of their blood.
Cat fleas (Ctenocephalides felis)
are responsible for many flea infestations, the remainder being
attributable to a variety of bird and animal species. Infestations by Pulex irritans (human fleas) are now uncommon. The significance of Ctenocephalides felis
is explained by the increased number of pets being kept and the
tendency for their beds to be neglected during cleaning. Wall to wall
carpeting also provides a relatively undisturbed environment for the larvae of fleas to develop, whilst the spread of central heating has served to
ensure ideal temperature conditions.
Pest Significance
Fleas
can be vectors of disease or may transmit parasitic worms. The most
serious infection which they can spread is bubonic plague, transmitted
to man by rodent fleas (Xenopsylla cheopis) which carry the
causative bacillus from infected rats. Rodent fleas may also carry
murine typhus and, because of their readiness to attack humans as well
as rats, are probably the major flea vector of disease. Dog fleas are
an intermediate host of the dog tapeworm, whose vertebrate host is
usually the dog but which can sometimes be transmitted to humans.
In
Europe, fleas are generally not responsible for the transmission of
disease. Nonetheless, fleas are still objectionable because of the bites
they inflict and the deep-rooted social stigma attached to humans with
flea infestations.
Bites from fleas are identified as a tiny dark
red spot, surrounded by a reddened area. The bite persists for one or
two days and is intensely irritating. First bites are not generally
liable to cause serious reactions, but they may lead to hypersensitivity.
Reactions are usually delayed following regular biting over a long
period; they then follow a period when reactions are immediate. The
cycle then repeats until a state of non-reactivity - immunity to the bite of fleas is
achieved.
Life Cycle
The development cycle of fleas from egg to adult is normally completed in four weeks, but at lower temperatures will take much longer.
The eggs of fleas are about 0.5mm long, oval, pearly-white in colour and laid in the
fur or feathers of the host of in its nest of bedding. They do not
adhere to the host but readily fall from the animal, are shaken or off.
The same applies to to the dark coloured faeces of the adult fleas,
thus creating the black and white - salt and pepper - effect associated
with infestations of fleas. Four to eight eggs are laid after each blood
meal and a single female may produce 800-1000 eggs during her lifetime,
which may be as long as two years.
The eggs hatch in about one
week to give white, threadlike, legless larvae 1.5mm. The larvae of fleas thrive
in dark, humid places such as animal bedding and carpet fluff, and feed
on organic debris and adult flea excrement. A cat's bedding may support
a population of 8,000 immature and 2,000 adult fleas. After 2-3 weeks,
by which time they will have moulted twice and be about 5mm long, the fleas
larvae spin silken coccoons, incorporating debris, in which to pupate.
This is the quiescent phase
and the flea may overwinter in this state. The adult flea is stimulated
to emerge by the vibrations set up by a passing host. This explains the
occasional mass attacks which take place in deserted premises.
Control
In
many instances infestations of fleas in well-kept houses can be easily traced to
pets. Where this is not the case it is useful to establish the pest
species. This will help to identify possible hosts and even the foci of
the infestations. Control measures must be directed at the brood as
well as the adult fleas.
Hygiene/Management:
Regular cleaning will deny the insects their ideal breeding conditions
and so make an important contribution towards their control. Infested
clothing, beds and bedding should be destroyed by burning or thoroughly
cleaned and the same measures employed when dealing with any old bird
and animal nests you may find. Accumulations of debris should also be
removed from cracks and crevices such as between floorboards, and the
whole area thoroughly cleaned.
Insecticidal control:
Insecticidal products are available which have been specifically
formulated and registered for use on the host animals themselves. Only
these products should be applied to animals and care should be taken to
follow the manufacturers' instructions. The PCP UK Flea Killer Kit
comprises several products which are safe for use in areas frequented
by pets, and even on pet bedding, including a specialist Household Flea
Spray. The use of a residual insecticide on wider areas may be
beneficial. Protector C is a potent insecticide with lasting residual action, deadly
to a wide range of insects, but harmless to mammals and humans, and
with no staining or smell once dry. Available in 5 litre bottle, for
application with hand sprayer, or in a handy 1 Litre Trigger Pack .
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