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Biomedical subjects

R Velayudhan

Publications and source records attributed to R Velayudhan.

3 recordsLinked to original sources
PubMed1991

Tralomethrin (OMS-3048), a new synthetic pyrethroid against vector mosquitoes.

Tralomethrin (OMS-3048) a synthetic pyrethroid, was tested for its insecticidal properties in the laboratory against normal strains of Culex quinquefasciatus, Cx. tritaeniorhynchus, Cx. sitiens, Anopheles stephensi, An. culicifacies, Aedes aegypti and Armigeres subalbatus and against strains of Cx. quinquefasciatus resistant to fenthion and malathion. Tralomethrin showed good larvicidal activity against all the species tested. LC50 ranged between 7.00 x 10(-6) and 9.10 x 10(-3) mg (ai)/l. Resistant strains of Cx. quinquefasciatus showed higher tolerance than the normal strain. Tralomethrin was more effective against adults of An. culicifacies (LD50 0.18 micrograms/cm2) than the other species. Residual activity of this compound lasted for 15 weeks on thatch surface at a dosage of 50 mg (ai)/m2 against all the mosquito species tested. In the field, this compound was effective for a period of 1-2 days in polluted water viz., cesspits and drains and 10-24 days in less polluted water as in cement tanks, when applied at the rate of 0.002-2.0 mg (ai)/l against immatures of Cx. quinquefasciatus.

Aedes↗
PubMed1990

Insecticidal activity of carbosulfan (OMS 3022) and pyraclofos (OMS 3040) against mosquitoes.

Carbosulfan (OMS 3022), a carbamate and pyraclofos (OMS 3040), an organophosphate were evaluated for their biological activity against vector mosquitoes, both in laboratory and field conditions. Carbosulfan (25% EC), was found to be active against adults and immatures of Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti. The LD values for adults were 6.65, 5.19 and 8.35 micrograms/cm2 and LC 50values for immatures were 5.4 X 10(-5), 1.6 X 10(-4 and 5.4) X 10(-4) 50mg/1 respectively. Pyraclofos (50%) showed neither larvicidal nor adulticidal activities. The residual effect of carbosulfan (25% WP) on cement, thatch and mud surfaces at 400 mg (ai)/m2 lasted for 3, 16 and 21 weeks respectively. In the field, carbosulfan at 2.00 kg (ai)/ha resulted in complete control of C. quinquefasciatus larvae for a period of one week in cement tanks and less than a week in other polluted water bodies, such as cesspits, cesspools and drains. Pyraclofos was not effective at a dose of 2.00 kg (ai)/ha in any of the habitats.

Animals↗