Keberkesanan langsir berubat piretroid sebagai penghalang kepada kemasukan nyamuk ke dalam rumah dan keberkesanan bacillus spp. mengawal.. larva nyamuk dalam sawah padi
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Date
1998
Authors
Md. Ramli, Shahrem
Journal Title
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Abstract
The effect of curtains impregnated with permethrin (0.5 g/m2
), cyfluthrin (0.05
g/m2
) and lambdacyhalothrin (0.025 g/m2
) on the total number of mosquitoes
biting human indoors and those resting indoors was studied for 12 consecutive
weeks. A total of 919 mosquitoes were sampled biting human indoors. The
genus Mansonia (41.2%) was the most dominant biting on human indoors and
Anopheles (8.1 %) was the least. Total number of mosquitoes biting on human
indoors and those resting indoors were successfully reduced by the pyrethroid
impregnated curtains. No difference was observed in the efficacy between the
three insecticides used. Bioassay test using the WHO cone on the treated
curtain found that the percentage of mosquitoes knockdowned after an hour of
exposure to the curtain was significantly declined in relation to the age of the
curtain (weeks) being used. Lambdacyhalothrin treated curtain did not show
any decline in efficacy in relation to time.
The efficacy of Bacillus thuringiensis H-14 and Bacillus sphaericus in
controlling mosquito larval population in ricefield and their effect on non-target
organisms were studied for 22 days. A three week pretreatment survey showed
Culex constituted 96.4% of the total larval population while Anopheles
constituted only 3.6%. The three most dominant spesies were Cx. gelidus, Cx.
tritaeniorhynchus and Cx. pseudovishnui. For B. thuringiensis, two formulations
were used; Aquabacxtn.t (emulsifiable concentrated) and LarvXn.tSG (sand
granule). As for B. sphaericus, Vectolexn{ WG (wettable granule) was used. It
was found that LarvXn1SG was ineffective in reducing mosquito larvae in the
treated plot compared to Aquabacxtâ„¢ and Vectolexn.t WG. The best control
was using by Vectolexn1 WG for a period of 15 days where larval reduction was
between 90-100%. Rain fall and water temperature did not influence the
efficacy of all larvicide formulations used. The three larvicide formulations did
not show any negative effect on non-target insects from the family Baetidae,
Libellulidae, Dytiscidae, Notonectidae, Coenagrionidae, Naucoridae,
Hydrophilidae as well as tadpoles.
Description
Keywords
Keberkesanan bacillus , Larva nyamuk