Kajian faktor fisiologi nyamuk berkaitan dengan kesan selepas pendedahan kepada lingkaran nyamuk
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Date
1995-03
Authors
Hong Peng, Lim
Journal Title
Journal ISSN
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Abstract
A study on physiological factors of mosquitoes in
relation to the effects of exposure to mosquito coils.
Three mosquito coil formulations with active
ingredients d-a11ethrin (0.2% w/w) and d-trans allethrin
(0.1% w/w) and blank coil have been tested in the
laboratory against Culex quinquefasciatus Say and Aedes
aegypti (Linnaeus) using a standard test method of the
Standard & Industrial Research Institute Of Malaysia
(SIRIM). Laboratory cultured mosquitoes established from
Penang Island were used in this study. Mosquito coil
( 0.50 ±. 0 .003g) with both ends ignited were tested in
glass chamber measuring 70 X 70 X 70 em.
Results indicated that Ae. ae9ypti was more
susceptible to mosquito coils than ex. quinquefasciatus .
.so
For example, the knockdown values (KTSO) for female Ae.
ae9ypti and ex. quinquefasciattts aged day 4-5 tested
against mosquito coil containing d-allethrin (0.2% w/w)
were 2.24 ±. 0.02 minutes and 8.82 ±. 0.39 minutes,
respectively. The blank coil caused neither significant
-
knockdown nor mortality of mosquitoes, while coils
containing d-allethrin (0.2% w/w) and d-trans allethrin
(0.1% w/w) could provide adequate knockdown of mosquitoes
but with low mortalities. For example, the percentage
mortalities of female Ae. aegypti and ex.
quinquefasciatus aged day 4-5 tested against mosquito
coil containing d-allethrin (0.2% w/w) were 13.67 ± 2.59%
and 6.00 + 0.76%, respectively. Furthermore, the
efficacies in term of knockdown and mortality for d-
r allethrin (0.2% w/w) and d-trans allethrin (0.1% w/w) ~
were not siginificantly different.
The susceptibility of mosquitoes to mosquito coils
increased with age. Percentage mortalities of both
mosquitoes species tested showed a positive relationship
with aging. For example, the percentage mortalities
of female Ae. aegypt.i tested against d-trans· allethrin
(0.1% w/w) were 13.67 + 2.62%, 17.50 + 4.19%, 18.17 ±
2.17%, 51.17 ± 10.08% and 72.00 ± 15.74% when mosquitoes
were assessed at age day 1-2, 4-5, 9-10, 14-15 and
19-20, respectively. Besides, female mosquitoes were
more tolerant than the males. This study also indicated
that blood-fed mosquitoes were more difficult to knockdown
but· easier to kill than non blood-fed mosquitoes.
However, the susceptibility -of mosquitoes to mosquito
coils was not affected by oviposition.
The longevity of both mosquito species decreased
more than 40% after being exposed to mosquito coils·
containing d-allethrin (0.2% w/w) and d-trans allethrin
(0.1% w/w). The percentages of mosquitoes blood-feeding
for· ex. quinquefascistus and Ae. segypti were reduced to
less than 20% and 55%, respectively after a 20 minute
exposure to d-allethrin (0.2% w/w) and d-trans allethrin
( o .1% w. w). Furthermore, ex. qui nquefssci atus also
·showed a decrease in blood-feeding ability ( <40%) after
being exposed to blank coils. Nevertheless, the number
of eggs oviposited by the treated females were not
affected if the mosquitoes were able to blood-feed. This
study also indicated that physiological effects on the
mosquitoes after mosquito coil exposure were not carried
over to the next generation.
Description
Keywords
Fisiologi nyamuk , Pendedahan kepada lingkaran nyamuk