| dc.description.abstract | Developmental cycle of Trypanosoma (Nannomonas)
congolense Broden in Glossina morsitans centralis Machado, ~.
fuscipes fuscipes Newstead and~. brevipalpis Newstead was
investigated with a view to better understand this subject and, to
compare cyclical development of two different I. (N.) congolense
serodemes in the three different tsetse species belonging to
morsitans, palpalis and fusca groups. Results showed that both
these I. (N.) congolense serodemes completed cyclical development
in the three tsetse species by day 25 after the infected feed.
However, variation in susceptibility to the infection between the
three tsetse species, was evident. The cycle of development was
confined ,to the midgut and proboscis. No haemocoelic infection
was observed. Survival of I. (N.) congolense (IL 1180 and IL
2281) was best in ~. ffi. centralis (44.2%; 45.0%), intermediate in
§. brevipalpis (9.7%; 7.5%) and poor in §. f. fuscipes (0%; 2.5%).
Differences in the gut. environments of different laboratory-bred
cultures of Glossina Westwood species and subspecies have been
suggested such that I. (N.) congolense parasites can survive
better in the guts of some than others and undergo cyclical
development to metacyclics in the hypopharynx.
The transmission frequency of infection to mice by §. ffi.
centralis and §. brevipalpis infected with I. (N.) congolense IL
1180 and the number of trypanosomes discharged by infected §. ffi.
centralis at a single feed were also studied. Results showed that
. centralis transmitted the infection more efficiently (94.0%)
than ~. brevipalpis (23.5%). The mean number of trypanosomes
discharged at a single feed by~. m.centralis was 93.04±10.0.
There was no significant difference between the male and female
tsetse in this respect. The survival and reproductive performance
of the three different tsetse given infected feed as tenerals were
compared. Results suggested that development of I. Uf. )
congolense IL 1180 in the three tsetse species had no deleterious
effect on their survival and on the reproductive performance of
the female tsetse. The weights of the puparia, their emergence
rate and sex ratios of the emergent flies were not affected by the
infection.
Effect of higher than optimum incubation temperature of
puparia and maintenance temperature of infected adults of ~. m.
central is, ~. f. fuscipes and ~. brevipalpis on I. (N.) congolense
IL 1180 infection rates were also investigated. Results showed
that, tsetse produced by puparia of ~. m. centralis incubated at
290±1 oC, and the pupar ia of three speci es incubated at 280±10C
during the day and 250±loC at night were more susceptible to I.
(N.) congolense IL 1180 infection than tsetse produced by puparia
incubated at 250±10C. The maintenance temperature of the infected
adults did not appear to affect the infection rates. | en |
