Agriculture Reference
In-Depth Information
The key to successful control of insect and insect-like pests is knowledge
of the stage(s) of their life cycle in which they are most vulnerable. It is gen-
erally difficult to control insects in either the egg or pupal stage, because these
stages are inactive: not feeding, immobile, and often in inaccessible areas such
as underground, in cocoons or cases, and in cracks or crevices.
Controlling insects in the late instar and adult stages is moderately suc-
cessful. The insects, because of their size, are most visible in these stages and
usually are causing the most destruction. Therefore, control attempts are often
begun at these times. However, the larger insects are often more resistant to
pesticides, and adults already may have laid eggs for another generation.
The best control usually is achieved during the early larval or nymphal
stages when the insects are small and vulnerable. Control during these stages
requires careful monitoring of pest populations and thorough knowledge of the
pest's life cycle, habitats, and feeding patterns.
Environmental conditions, such as humidity, temperature, and availability
of food, can alter the rate of growth of insects and thus affect the length of the
life cycle. Optimum environments (usually warm and humid) can decrease the
time of development from egg to adult.
1.
Insect Control Strategy
Control methods used for insects include:
•
host resistance
•
biological control
•
cultural control
•
mechanical control
•
sanitation
•
chemical control.
a.
Host Resistance
Some crops, animals, and structures resist insects and their relatives better
than others. Some varieties of crops and wood are immune to certain insects.
Use of resistant types helps keep pest populations below harmful levels by
making the environment less favorable for the pests.
