Medical Research Institute Department Of Entomology 23.05.11 Registrar of Pesticides Office of the Registrar of Pesticides Department of Agriculture Getambe Peradeniya Report on the biological efficacy of Mosquito larvicide Sample No. WP/10/21 and RH/0/22 (Bacillus thuringiensis) The biological efficacy of Mosquito larvicides, sample numbers WP/10/21 and RH/0/22 (Bacillus thuringiensis ) were tested against the laboratory reared 4* instar larvae of Aedes aegypti. The larval bio assays were carried out according to the WHO guidelines for the laboratory testing of mosquito larvicides. Laboratory reared 25, 4* instar larvae were exposed to 4 replicates as well as for the controls. The mortality was counted after 24 hr exposure period. Observation - 100% mortality of the larvae of Aedes aegypti were observed in all the replicates used. The residual activity of the products were observed upto 30 days under laboratory conditions and 100% mortality of the mosquito larvea were observed during that period. The biological efficacy of the Mosquito larvicides, sample numbers WP/10/21 and RH/0/22 were tested under field conditions, according to the WHO guidelines for the testing of mosquito larvicides. In these trials, artificial containers (barrels.) of water were placed in the field and mosquito larvicides were tested against field-collected larvae. The water-filled containers were given a period of 24 h for conditioning. A batch of 50 field collected , third instar larvae of Aedes aegypti, were released into each container and larval food was added. Four replicates were carried out with a control. The containers were treated with mosquito larvcides and covered with nylon mesh screen to prevent other mosquitoes or other insects from laying eggs. All the containers were examined afte 24 hrs. and live larvae were counted to score post-treatment larval mortality. To test residual activity, a new batch of field collected / laboratory-reared, late third / early 4'*' instar larvae of the same mosquito species were introduced to each container, and mosquito larval food was added on alternate days or weekly. Larvae survival was assessed 24 h post addition. This process continued upto 30 days. Observation - 100% mortality of Aedes aegypti was observed after 24 hrs. of the application of the product. The residual effect of the mosquito larvicides sample numbers WP/10/21 and RH/0/22 were was observed for 30 days and observed 100%) mortality of Aedes aegypti during that period Thanking you. Yours sincerely Dr. l.S.Weerasinghe Entcmol'-yist ^ Dop-^itrnent of Er,?.oviio?ogy rjU?dicai Rc-scafcl» instituti-- DR DANISTER DE SILVA MAWATHA PHONE: 94- 1 1 - 2 6 9 1 3 50 FAX: 94- 1 1 -269 1 4 50 COLOMBO 8 SRI LANKA

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Medical Research Institute Department Of Entomology

23.05.11 Registrar of Pesticides Office of the Registrar of Pesticides Department of Agriculture Getambe Peradeniya

Report on the biological efficacy of Mosquito larvicide Sample No. WP/10/21 and RH/0/22 (Bacillus thuringiensis)

The biological efficacy of Mosquito larvicides, sample numbers WP/10/21 and RH/0/22 (Bacillus thuringiensis ) were tested against the laboratory reared 4* instar larvae of Aedes aegypti. The larval bio assays were carried out according to the WHO guidelines for the laboratory testing of mosquito larvicides. Laboratory reared 25, 4* instar larvae were exposed to 4 replicates as well as for the controls. The mortality was counted after 24 hr exposure period.

Observation -100% mortality of the larvae of Aedes aegypti were observed in all the replicates used. The residual activity of the products were observed upto 30 days under laboratory conditions and 100% mortality of the mosquito larvea were observed during that period.

The biological efficacy of the Mosquito larvicides, sample numbers WP/10/21 and RH/0/22 were tested under field conditions, according to the WHO guidelines for the testing of mosquito larvicides. In these trials, artificial containers (barrels.) of water were placed in the field and mosquito larvicides were tested against field-collected larvae. The water-filled containers were given a period of 24 h for conditioning. A batch of 50 field collected , third instar larvae of Aedes aegypti, were released into each container and larval food was added. Four replicates were carried out with a control. The containers were treated with mosquito larvcides and covered with nylon mesh screen to prevent other mosquitoes or other insects from laying eggs. Al l the containers were examined afte 24 hrs. and live larvae were counted to score post-treatment larval mortality. To test residual activity, a new batch of field collected / laboratory-reared, late third / early 4'*' instar larvae of the same mosquito species were introduced to each container, and mosquito larval food was added on alternate days or weekly. Larvae survival was assessed 24 h post addition. This process continued upto 30 days.

Observation - 100% mortality of Aedes aegypti was observed after 24 hrs. of the application of the product. The residual effect of the mosquito larvicides sample numbers WP/10/21 and RH/0/22 were was observed for 30 days and observed 100%) mortality of Aedes aegypti during that period

Thanking y o u . Yours s incerely

Dr . l .S.Weerasinghe

Entcmol'-yist ^ Dop-^itrnent o f Er,?.oviio?ogy rjU?dicai Rc-scafcl» instituti--

D R D A N I S T E R D E S I L V A M A W A T H A

P H O N E : 9 4 - 1 1 - 2 6 9 1 3 50 F A X : 9 4 - 1 1 - 2 6 9 1 4 50

C O L O M B O 8 S R I L A N K A