Few persons understand mosquito control beyond the spray can level. Often houses with doors and windows open are sprayed by aerosols from a truck. Such results may be almost impossible to evaluate. Spraying inside by backpack is much better. If DDT is used, warn the householders of possible staining of walls.

One fumigant spiral burnt per floor of a house kills all, evinced by dead cockroaches. Fumigants are sold by Johnson, Bayer, Shell and others. Open drawers, closets and so on, and close the house and stay out of it for 2 hours upon lighting the spiral or canister. Air out the house for a half hour before reoccupying it.

Fumigation with 5 % b -cypermethrine (Bolate) for 2 hours kills all adult and larval mosquitoes. It can be applied at 20 houses per worker per day.