Blackflies are blood-sucking insects that breed in flowing streams. Larvae are
found attached to rocks and vegetation in the streams. Certain species in Mexico,
South America, and Africa carry disease, and they occur as annoying pests in other
parts of the world.
Clothes moths and carpet beetles do extensive damage to woolen or woolcontaining materials. Chlordane, lindane, and dieldrin are effective but dangerous,
especially inside the home. Preferable control is through exposure to sunlight and
storage in tight containers with naphthalene, paradichlorobenzene, or camphor.
Killer bees or Africanized honey bees are venomous and very aggressive, capable
of killing large animals when swarming. They have spread throughout Central and
South America, and have only slowly moved into the southern United States because
of climate limitations [13].
7.4 Vertebrates
The use of poisons to regulate pest populations of vertebrates is rarely popular. With
the exception of the killing of rats, many people oppose chemical measures (or any
measure) to control the higher animals. These animal pests, however, produce
considerable damage and can wipe out whole crops of grains or fruits, interfere
with planting by feeding on the sown seed, destroy trees through bark stripping, and
damage lawns by burrowing.
Easiest to control are the burrowing animals. Gassing the burrows with hydrogen
cyanide or phosphine is effective, as is baiting the burrows with poisoned
earthworms.
Overpopulation of certain fish species that have no value for angling or fish
production may result in a decision to completely remove all fish. This can be done
with several fish toxicants such as rotenone, antimycin A, and toxaphene. A certain
amount of success results from partial and selective poisoning [14].
A chemical approach that seems acceptable is the use of repellents. The ultimate
effect is to force the animal to alternative foods or to starve it. Populations become
regulated according to the size of the food supply. In making part of the food supply
unavailable through the use of repellents, competition for the available food
becomes more intense, resulting in successful and unsuccessful competitors. The
effect of repellents is most often too transient for effective control. Since higher
animals have a learning capacity, they quickly find out if a repellent is only
distasteful and not harmful. Under such conditions, protection is short if the animal
is hungry. For a critical period, however, such as seed germination, the use of
repellents can be highly effective. Such an example is the coating of corn seed
with liquid coal tar to repel crows.
Another chemical approach is the use of nonlethal narcotics, such as chloralose
[9]. This can be used to dust grain, which will produce sleepiness in birds shortly
after consumption. Selective control of pest birds can be made by dusting large seeds
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found attached to rocks and vegetation in the streams. Certain species in Mexico,
South America, and Africa carry disease, and they occur as annoying pests in other
parts of the world.
Clothes moths and carpet beetles do extensive damage to woolen or woolcontaining materials. Chlordane, lindane, and dieldrin are effective but dangerous,
especially inside the home. Preferable control is through exposure to sunlight and
storage in tight containers with naphthalene, paradichlorobenzene, or camphor.
Killer bees or Africanized honey bees are venomous and very aggressive, capable
of killing large animals when swarming. They have spread throughout Central and
South America, and have only slowly moved into the southern United States because
of climate limitations [13].
7.4 Vertebrates
The use of poisons to regulate pest populations of vertebrates is rarely popular. With
the exception of the killing of rats, many people oppose chemical measures (or any
measure) to control the higher animals. These animal pests, however, produce
considerable damage and can wipe out whole crops of grains or fruits, interfere
with planting by feeding on the sown seed, destroy trees through bark stripping, and
damage lawns by burrowing.
Easiest to control are the burrowing animals. Gassing the burrows with hydrogen
cyanide or phosphine is effective, as is baiting the burrows with poisoned
earthworms.
Overpopulation of certain fish species that have no value for angling or fish
production may result in a decision to completely remove all fish. This can be done
with several fish toxicants such as rotenone, antimycin A, and toxaphene. A certain
amount of success results from partial and selective poisoning [14].
A chemical approach that seems acceptable is the use of repellents. The ultimate
effect is to force the animal to alternative foods or to starve it. Populations become
regulated according to the size of the food supply. In making part of the food supply
unavailable through the use of repellents, competition for the available food
becomes more intense, resulting in successful and unsuccessful competitors. The
effect of repellents is most often too transient for effective control. Since higher
animals have a learning capacity, they quickly find out if a repellent is only
distasteful and not harmful. Under such conditions, protection is short if the animal
is hungry. For a critical period, however, such as seed germination, the use of
repellents can be highly effective. Such an example is the coating of corn seed
with liquid coal tar to repel crows.
Another chemical approach is the use of nonlethal narcotics, such as chloralose
[9]. This can be used to dust grain, which will produce sleepiness in birds shortly
after consumption. Selective control of pest birds can be made by dusting large seeds
404
L. S. Clesceri and E. J. Clesceri