Figure 5-8. Aerosol bomb.
e. Area Control.
(1) Vegetation. Where the vector species utilize wooded resting places, area
spraying of vegetation may be expected to contribute to areas, observation posts, gun
emplacement, and so forth, by spraying vegetation with currently recommended
residual effect insecticide in a strip surrounding the area to be protected.
(2) Area control with mist blowers or fog machines. Temporary relief from
adult mosquitoes may be secured in open areas by the use of insecticides in the form of
mist or wet heavy fog.
-- If fogging or misting is carried out on a regular schedule, a
measurable freedom from adult mosquitoes may be maintained in an area which is also
receiving good residual and larval treatment. Fogging or misting is not in any case a
substitute for proper larviciding or residual spraying.
-- A special type of fogging is Ultra Low Volume (ULV) spraying in
which small volumes of nearly concentrated (> 90 percent concentration) pesticide are
applied as extremely small droplets.
-- To be effective, fogging or misting must be done during calm weather
(wind under five miles per hour), at night or, preferably, early in the morning, in order to
prevent too much dispersion of the insecticide by thermal updrafts.