Intira Pipitgool. Effectiveness of alternative larvicides against temephos-resistant Aedes aegypti populations from Thailand, under laboratory conditions . Master's Degree(Tropical Medicine). Mahidol University. : Mahidol University, 2007.
Effectiveness of alternative larvicides against temephos-resistant Aedes aegypti populations from Thailand, under laboratory conditions
ประสิทธิภาพของยาฆ่าแมลงทางเลือกใหม่ในการกำจัดยุงลาย Aedes aegypti ที่มีความต้านทานต่อทีมีฟอส (ทรายอะเบท) ในประเทศไทย (ในห้องปฏิบัติการ)
Abstract:
Aedes aegypti is an important mosquito-borne disease in Thailand. Recently,
temephos has been commonly used in the control of mosquito larvae, especially Ae.
aegypti. Its widespread use has resulted in temephos resistance, which will cause a
serious problem for control of this species in the future. Bacillus thuringiensis
israelensis (Bti) and the insect growth regulator, pyriproxyfen are important
developing insecticides for the control of insecticide resistant Ae. aegypti. This
research was performed to determine the activity of Bti and pyriproxyfen as an
alternative larvicide for the control of Ae. aegypti. Samples of temephos-resistant Ae.
aegypti from Muang District, Buriram (LC50=0.01317, LC90=0.03131, RR50=12.08,
RR90=12.78); Huai Khwang (31) District, Bangkok (LC50=0.01146, LC90=0.02902,
RR50=10.51, RR90=11.84), Thailand, and a susceptible strain, Bora Bora
(LC50=0.00109, LC90=0.00245) were the subjects of study. Insecticide resistance
mechanisms were detected. Biochemical tests, polyacrylamide gel electrophoresis
(PAGE) and inhibition studies showed that elevated esterase activity is associated
with temephos resistance. The effectiveness of Bti against mosquito resistance was
observed when mosquito larvae were sequentially exposed to temephos and Bti. The
results showed that all temephos-resistant Ae. aegypti populations had no resistance to
Bti. In conclusion, Bti can be used to eliminate temephos-resistant Ae. aegypti
mosquitoes. The effectiveness of pyriproxyfen were tested with the same procedure
as Bti; the results showed that all temephos-resistant Ae. aegypti populations had a
potential cross-resistance to pyriproxyfen, but pyriproxyfen still has efficiency to
inhibit the emergence of mosquitoes.