The effect of dieldrin exposure on Anopheles gambiae (Diptera: Culicidae): fitness, fecundity and fertility.
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Date
2013-01-23
Authors
Norton, Ryan Anthony Ingram
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Abstract
The effect of dieldrin exposure on fecundity, fertility and longevity was investigated in
two populations of the African malaria vector Anopheles gambiae s.s: A wild
representative strain and a laboratory strain were used. Experimental procedures were
designed and optimised to obtain the maximum amount of data for individual females. In
some instances, novel experiments had to be designed to answer specific research
questions as no similar studies were available in the literature. A compilation of reference
photographs depicting the different stages of oocyte growth in An. gambiae females was
produced to assist in the identification of growth phases. Fecundity was shown to be
reduced in dieldrin exposed females with close correlation to egg retention. Oocyte
developmental rate was reduced in both populations of mosquitoes after exposure to
dieldrin. Longevity was observed to decrease in the wild strain and remained unchanged
in the laboratory strain when compared to the unexposed controls. Fertility was generally
decreased, however dieldrin exposure appeared to have no negative affect on mating or
spermatozoan viability before or after mating in male testes or female spermathecae
respectively. In summary this study showed that exposure to dieldrin had subtle effects on
the biology of these mosquitoes, but would probably not have a detrimental effect on a
population as a whole.