| dc.description.abstract | The sandfly Phlebotomus martini is the vector
to man of the disease visceral leishmaniasis, otherwise
known as kala-azar. This disease has been known to exist
in Kenya since the second world war. The most recent
epidemic occured in the Machakos district in 1971 and is
still going all.
Thus, the ~roblem that workers in the field of
visceral leishmaniasis face is effective control and/or
eradication of this disease. Information about the
biology and breeding sites of Phlebotomus martini is
required. Before this investigation, however, previous
endeavours to study the biology and the breeding sites
of this insect were me~ with failure. The objective of
this investigation was to elucidate on the methods of
rearing Phlebotomus martini in the laboratory and also
studying its biology. This might lead to the clues of
the breeding sites Qf this sandfly and help in planning
its effective control.
Collection of pregnant females of Phlebotomus
martini from Kalawa in Machakos district took place at
regular intervals in the year 1978/1979. The females
were cap"tured by allowing them to feed fully on the
plood of volunteers including myself. These were then
placed in plastic rearing cages under appropriate conditions
of temperature (26°C - 28°C) and humidity
(saturation). Observations were then carried out on egg
laying and on the other stages of the life cycle.
The fesults show that a female laid from 1 to
55 eggs within a range of 4 - 11 days. The larva that
emerged (lstinstar) measured 0.5 mm long and 0.1 mm wide.
There were 4 larval instars altogther, the 4th instar
being 1.6 mm by 0.25 mm. These larvae had tailor caudal
hairs, one pair in the case of the 1st instar and two
pairs in the case of the other three instars. The 4th
instar went into the pupal stage finally. The flies
emerged after 10 - 12 days. The cycle from adult to
imago tookan average of 56 days.
The density of Phlebotomus martini is seasonal;
they are usually avail-able in large numbers only after
the rainy season. The places where both the disease and
the flies occur are in remote areas which are not easily
accessible by road. Also, the females caught were highly
sensitive to handling and transportation and a high
mortality was observed even before egg laying. High
mortality of 1st and 4th instar larvae was also observed.
The external morphology of the various larval
and pupal stages were studied and the details in full
are presented in the main text. Comparison was made with
other immature stages of previously studied sandfly
species and no distinction was observed between them under
light microscopic observations. It is possible that
observations under higher magnificat~ons, using scanning
electron microscopy, might bring out distinctive features
which might lead to larval identification of species.
This remains a future problem. With more trials and
time, some problems aforementioned should be overcome
and a laboratory colony of Phlebotomus martini estab--
lished to serve as material for infectivity experiments
with the leishmania parasites which may in turn lead
to further knowledge of the behaviour of the parasite in
this vector species. | en |
