5. Multiple Crops on Agricultural Land
Insect infestation that frequently occurs with monoculture is controlled by
multiple plantings. Alternating rows of susceptible with nonsusceptible crops
serves to confine the pests and prevent the widespread infestation that can occur
when an unlimited supply of food is contiguous to the initial infection.
6. Natural Predators
The use of natural predators that consume developing or adult stages of pests
is ideal if the predator itself does not become a pest. Ladybugs are among the
most effective destroyers of a variety of plant-eating insects. The preying mantis
lives exclusively at the expense of other insects. Yellow jackets feed on softbodied insects. Adult dragonflies feed on mosquitoes, whereas their young,
naiads, prey on the developing stages of the mosquito and other insects in the
waters below.
7. Sterile Mating
Some success has been met in combating undesirable organisms by capturing, sterilizing (usually with radiation), and releasing sterile mates into the
environment. The relative effectiveness of this program, of course, depends
upon how many fruitful matings can be prevented.
8. Competition
Enhancement of the growth of a competitor is frequently possible. For
example, one can replace weeds with a desirable ground cover by seeding
among the weeds. The cutting of weeds, especially when seeded with grass,
will accelerate succession to a more stable vegetation.
Mycotoxin contamination of agricultural commodities is a major threat to
stability of foods in storage. Aflasafe is an example of a product of fungal spores
used for competing with toxigenic strains to prevent the formation of toxic
aflatoxin-producing strains in soils. It is applied to soils to reduce toxicity of the
native soil fungal populations.
9. Use of Attractants
Many insects locate food, mating partners, and sites to lay eggs by being able
to respond to chemical stimuli emanating from these sources. Traps permeated
with these materials (pheromones) may physically restrain the insect by means
of a sticky surface or by drawing it through a small orifice, by killing the insect
outright by electric shock, or poisoning it with insecticides. Both natural and
synthetic attractants are used. Light is also commonly used as an attractant for
certain insects.
10. Physical Removal of Aquatic Weeds
Preferable to the use of pesticides is the physical removal of aquatic weeds.
This is feasible for the rooted macrophytes through weed cutting procedures.
Weed cutting and removal of the plants are better than removal by dredging,
since it leaves the sediment less disturbed to continue its role in the decomposition of sedimented organic material.
11. Use of Hormones
Hormonal pesticides can be used to selectively disturb growth, development,
and reproduction. When applied in excessive quantities or at abnormal times in a
392
L. S. Clesceri and E. J. Clesceri
Insect infestation that frequently occurs with monoculture is controlled by
multiple plantings. Alternating rows of susceptible with nonsusceptible crops
serves to confine the pests and prevent the widespread infestation that can occur
when an unlimited supply of food is contiguous to the initial infection.
6. Natural Predators
The use of natural predators that consume developing or adult stages of pests
is ideal if the predator itself does not become a pest. Ladybugs are among the
most effective destroyers of a variety of plant-eating insects. The preying mantis
lives exclusively at the expense of other insects. Yellow jackets feed on softbodied insects. Adult dragonflies feed on mosquitoes, whereas their young,
naiads, prey on the developing stages of the mosquito and other insects in the
waters below.
7. Sterile Mating
Some success has been met in combating undesirable organisms by capturing, sterilizing (usually with radiation), and releasing sterile mates into the
environment. The relative effectiveness of this program, of course, depends
upon how many fruitful matings can be prevented.
8. Competition
Enhancement of the growth of a competitor is frequently possible. For
example, one can replace weeds with a desirable ground cover by seeding
among the weeds. The cutting of weeds, especially when seeded with grass,
will accelerate succession to a more stable vegetation.
Mycotoxin contamination of agricultural commodities is a major threat to
stability of foods in storage. Aflasafe is an example of a product of fungal spores
used for competing with toxigenic strains to prevent the formation of toxic
aflatoxin-producing strains in soils. It is applied to soils to reduce toxicity of the
native soil fungal populations.
9. Use of Attractants
Many insects locate food, mating partners, and sites to lay eggs by being able
to respond to chemical stimuli emanating from these sources. Traps permeated
with these materials (pheromones) may physically restrain the insect by means
of a sticky surface or by drawing it through a small orifice, by killing the insect
outright by electric shock, or poisoning it with insecticides. Both natural and
synthetic attractants are used. Light is also commonly used as an attractant for
certain insects.
10. Physical Removal of Aquatic Weeds
Preferable to the use of pesticides is the physical removal of aquatic weeds.
This is feasible for the rooted macrophytes through weed cutting procedures.
Weed cutting and removal of the plants are better than removal by dredging,
since it leaves the sediment less disturbed to continue its role in the decomposition of sedimented organic material.
11. Use of Hormones
Hormonal pesticides can be used to selectively disturb growth, development,
and reproduction. When applied in excessive quantities or at abnormal times in a
392
L. S. Clesceri and E. J. Clesceri