Agriculture Reference
In-Depth Information
B.
OTHER METHODS
Unfortunately, natural controls often do not control pests quickly enough
to prevent unacceptable injury or damage. In these cases, other pest control
methods must be initiated. Those available include:
•
host resistance
•
biological control
•
cultural control
•
mechanical control
•
sanitation
•
chemical control.
1.
Host Resistance
Some crops, animals, and structures resist pests better than others. Some
varieties of crops, wood, and animals are immune to certain pests. Use of
resistant types helps keep pest populations below harmful levels by making
the environment less favorable for the pests. Host resistance works in two
main ways:
•
Chemicals in the host prevent the pest from completing its life cycle.
•
The host is more vigorous or tolerant than other varieties and thus less
likely to be seriously damaged by pest attacks.
2.
Biological Control
Biolo gical control invol ves the use of naturally occurring enemies—
parasites, predators, and disease agents (pathogens). It also includes methods
by which the pest is biologically altered, as in the production of sterile males
and the use of pheromones or juvenile hormones. Most kinds of biological
control agents occur naturally. Releasing more of a pest's enemies or preda-
tors into the target area can supplement this natural control.
Biological control is never complete. The degree of control fluctuates.
There is always a time lag between pest population increase and the corre-
sponding increase in natural controls. But, under proper conditions, sufficient
control can be achieved to eliminate the threat to the crop or animal needing
protection. Biological control can be a low-cost control method particularly
suited to low-value crops (pastureland, clover, and hay crops) or in areas where
some injury can be tolerated (golf course fairways or forest areas).
