Agriculture Reference
In-Depth Information
Harvest Timing
—Crops should not be left in the field after maturity if
they are susceptible to pest attack. For example, wireworm damage to mature
potatoes causes a serious quality reduction. Damage increases if the crop is
left in the ground even for a very short time after maturity.
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Mechanical Control
Mechanical controls used on insects are:
•
screens and other barriers
•
traps
•
light
•
heat and cold
•
radiation and electrocution.
Screens and Other Barriers
—A major aspect of insect control in-
doors is the use of screens and other barriers to keep insects out. Flying in-
sects, such as mosquitoes, wasps, and flies, are kept outside by blocking any
openings with screening. The effective mesh size depends on the size of the
smallest flying insect pests in that environment. Crawling insects are also
kept outside by screens or by other barriers such as tightly sealed doors and
windows. Barriers made of sticky substances sometimes can be used to stop
crawling insects from entering an area.
Traps
—Traps are sometimes used to control the target pest. More often,
however, they are used to survey for the presence of insect pests and to deter-
mine when the pest population has increased to the point where control is
needed.
Light
—Many insect pests may be attracted to artificial light at night.
However, since not all the pests are killed, the light attractant may actually
help create infestations.
Heat and Cold
—It is sometimes possible to expose insect pests to the
killing effects of the heat of summer or cold of winter. Insects that feed on
stored grain and flour, for example, can sometimes be controlled by ventilat-
ing grain elevators in winter.
Radiation and Electrocution
—Radiation and electrocution are some-
times used to kill pests in a limited area. The electric screens in such places
as outdoor restaurants and amusement parks are used to attract and electrocute a
variety of nocturnal insect pests. Ionizing radiation is used to sterilize pests
by destroying reproductive tissues, and ultrasonic radiation is used to kill pests
in some products.
