The disadvantages of oil usage –

• Repeated usage may hinder the vegetation growth
• Cannot be used on drinking water sources
• Small fishes in the water may be killed
• Strong winds can break the oil film

Destruction of Adult Mosquitoes:

This method is mostly used in house hold for killing adult mosquitos

Spraying on a systematic scale should be started before commencement of mosquito breeding and continued throught the malaria transmission season.

a) Pyrethrum spray

• Pyrethrum is prepared from dried flowers of Pyrethrum cinerarifolium plant
• Pyrethrum extract can be prepared by distillation to give 1% or 2% extract
• Mosquitoes get irritated and when the come into contact with suspended pyrethrum extract and the respiratory system are clogged and they die due to suffocation immediately.