control. When used in a preventative program, the effect is a stable, controlled
environment without the hidden costs of chemical poisoning. Many of the environmental control measures rest in the realm of biological control of one type or another.
Some of these attempts have backfired as the result of insufficient study before
employing them. Others, however, are tried and true measures. Illustrative examples
of these environmental control measures include the following:
1. Sanitation
Community and local sanitation to eliminate food, water, and harborage for
vertebrate pests (rodents, pigeons, etc.). This is the simplest and most effective
means for controlling such animals. A similar policy applies to the control of
wildlife, although this is much more complicated since many food alternatives
exist outside of the urban area. Thus, removing a single food source or even a
class of food sources will in all probability exert some control over the particular
wildlife species, but not to the extent that may be desired.
2. Maintenance of Healthy Plants
Plants that are less stressed are not as prone to attack by insects as unhealthy
plants. Insects mostly infest unhealthy plants, as strong plants can withstand
certain levels of herbivory. Plants that receive appropriate amount of sunlight,
that are well-watered, and that are in nutrient-rich and well-drained soils that are
protected from wind damage tend to be able to resist certain levels of insect or
fungal attack. In nature, weak organisms are typically attacked first. However,
the application of too much fertilizer or excess nitrogen is well documented to
correlate to increased pest prevalence.
3. Construction and Packaging
Exclusionary methods can take the form of different modalities. Tight construction prevents the use of the building as harborage for pests. In packaging of
perishable foodstuffs in storage bags, there are new applications for hermetic
sealing [3], which creates an anoxic environment inside the bag, reducing the
growth of insects that can be found in stored agricultural commodities requiring
oxygen for survival. Also, avoiding the contact of wooden structural members
with the ground and elimination of buried wood will discourage the development of termite colonies.
4. Elimination of Breeding Places
This is the most desirable way of controlling most arthropod pests. The
housefly thrives on any kind of waste (rotting vegetation, manure, sewage
sludge, etc.). Proper sanitation, installation of garbage grinders in kitchen
sinks, and use of fly traps are all measures that help in controlling flies without
insecticides. The elimination of standing water, controlled fluctuation of water
levels to alternatively flood and dry breeding areas, and the stocking of ponds
with top-feeding fish that consume larvae are effective means for combating the
mosquito where it breeds. Burning brush and long grasses that harbor mosquitoes, chiggers, etc., are another alternative to chemical poisoning.
10 Environmental Control of Pests and Vectors
391
environment without the hidden costs of chemical poisoning. Many of the environmental control measures rest in the realm of biological control of one type or another.
Some of these attempts have backfired as the result of insufficient study before
employing them. Others, however, are tried and true measures. Illustrative examples
of these environmental control measures include the following:
1. Sanitation
Community and local sanitation to eliminate food, water, and harborage for
vertebrate pests (rodents, pigeons, etc.). This is the simplest and most effective
means for controlling such animals. A similar policy applies to the control of
wildlife, although this is much more complicated since many food alternatives
exist outside of the urban area. Thus, removing a single food source or even a
class of food sources will in all probability exert some control over the particular
wildlife species, but not to the extent that may be desired.
2. Maintenance of Healthy Plants
Plants that are less stressed are not as prone to attack by insects as unhealthy
plants. Insects mostly infest unhealthy plants, as strong plants can withstand
certain levels of herbivory. Plants that receive appropriate amount of sunlight,
that are well-watered, and that are in nutrient-rich and well-drained soils that are
protected from wind damage tend to be able to resist certain levels of insect or
fungal attack. In nature, weak organisms are typically attacked first. However,
the application of too much fertilizer or excess nitrogen is well documented to
correlate to increased pest prevalence.
3. Construction and Packaging
Exclusionary methods can take the form of different modalities. Tight construction prevents the use of the building as harborage for pests. In packaging of
perishable foodstuffs in storage bags, there are new applications for hermetic
sealing [3], which creates an anoxic environment inside the bag, reducing the
growth of insects that can be found in stored agricultural commodities requiring
oxygen for survival. Also, avoiding the contact of wooden structural members
with the ground and elimination of buried wood will discourage the development of termite colonies.
4. Elimination of Breeding Places
This is the most desirable way of controlling most arthropod pests. The
housefly thrives on any kind of waste (rotting vegetation, manure, sewage
sludge, etc.). Proper sanitation, installation of garbage grinders in kitchen
sinks, and use of fly traps are all measures that help in controlling flies without
insecticides. The elimination of standing water, controlled fluctuation of water
levels to alternatively flood and dry breeding areas, and the stocking of ponds
with top-feeding fish that consume larvae are effective means for combating the
mosquito where it breeds. Burning brush and long grasses that harbor mosquitoes, chiggers, etc., are another alternative to chemical poisoning.
10 Environmental Control of Pests and Vectors
391