BLOOD SUCKING BUGS
FAMILY CIMICIDAE (BED BUGS)
The Cimicidae form a well-defined family of blood sucking bugs. They are
oval flattened insects without functional wings, although the forewings remain present
as two small pads on the dorsal surface of the thorax.
There are 91 recognized species of Cimicidae.
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Most
are associated with birds and/or bats but two species Cimex lectularius
and Cimex hemipterus are the familiar bedbugs commonly associated with
man.
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Both
species lay their eggs in cracks and crevices of houses and outbuildings.
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Each
female bedbug lays about 200 eggs, which hatch about after 10 days at 20 degree
Celsius.
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The
nymphs and adults usually feed at night when their hosts are sleeping, although
they will feed during the day if conditions are favourable.
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Feeding
behaviour, and hence development, is critically dependent on temperature and
humidity.
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Bedbugs
do not feed at temperatures less than 13 degree Celsius.
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Experimental
evidences show that bedbugs can be infected with a range of human parasites and
pathogens, including hepatitis-B, HIV and Trypanosoma cruzi.
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Bedbugs
will feed daily if given the opportunity and their high numbers can contribute
to chronic iron-deficiency anaemia, especially in infants.
FAMILY
POLYCTENIDAE (BAT BUGS)
The family
polyctenidae comprises 32 species grouped in five genera. They are small ectoparasites
of bats, with no known medical importance. They lack eyes and ocelli and are
always flightless with forewings reduced to small flaps. The bugs are
parthenogenetic. Bat bug Hesperoctenes.
FAMILY
REDUVIIDAE & AND SUBFAMILY TRIATOMINAE (KISSING BUGS)
Most reduviidae
are predators on insects and other invertebrates. They are predominantly
tropical, occupying a very wide range of terrestrial habitats and displaying a
variety of hunting strategies and pre preferences. Over 6000 species are known,
which are grouped into 23 subfamilies. In many predatory reduviids, the fore
legs are adapted to hold prey. Often the fore legs (sometimes mid legs) are
strongly raptorial, equipped with spines, adhesive organs and/or glands
secreting a glue-like substance.
Subfamily
Triatominae (Kissing bugs)
There are
118 species of Triatominae recognized on the basis of morphological characters.
They range from 5mm to 45 mm in length.
All species
of triatominae are obligate bloodsuckers and over half have been shown
naturally or experimentally to be susceptible to infection with Trypanosoma
cruzi.
Epidemiologically
only about a dozen species have become sufficiently closely associated with man
to represent a public health problem; of these the most important vector
species are Triatoma infestans, Panstrongylus megistus, Rhodnius prolixus,
Triatoma brasiliensis and Triatoma dimidiata.
Other species
are mainly associated with nest-building birds and small mammals, and occasionally
reptiles.
References
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Medical Insects and Arachnids Edited by
Richard P. Lane and Roger W. Crosskey. Published in 1993 by Chapman & Hall
ISBN 0 412 400006
