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Pest Control, Termite Treatment & Exterminator
Pest control refers to the regulation or management of another species defined
as a pest, usually because it is detrimental to a person's health, the ecology
or the economy.
Pest control is at least as old as agriculture. In order to maximize food
production, it is necessary to protect crops from competing species of plants,
as well as from herbivores competing with humans. This can be done with
conventional, chemical or biological weapons.
The conventional approach was probably the first to be employed, since it is
comparatively easy to destroy weeds by burning them or plowing them under, and
to kill larger competing herbivores, such as crows and other birds eating seeds.
Techniques such as crop rotation, companion planting, also known as
intercropping or mixed cropping, and the selective breeding of pest-resistant
cultivars also have a long history.
Many pests have only become a problem because of the direct actions of humans.
Modifying these actions can often substantially reduce the pest problem. In the
USA, raccoons caused a nuisance by tearing open refuse sacks. Many householders
introduced bins with locking lids, which deterred the raccoons from visiting.
Seagulls have become a pest at many seaside resorts. Tourists would often feed
the birds with scraps of fish and chips, and before long, the birds would become
dependent on this food source and act aggressively towards humans. Many local
authorities have now erected signs warning visitors not to feed the seagulls.
Chemical pest control dates back to 2500BCE, when the Sumerians used sulphur
compounds as insecticides. The Rig Veda (c. 2000BCE) also mentions the use of
poisonous plants for pest control. And the ancient Chinese and Egyptians are
also known to have used chemical pest control. But it was only with the
industrialization and mechanization of agriculture in the 18th and 19th century,
and the introduction of the insecticides pyrethrum and derris that chemical pest
control became the method of choice. In the 20th century, the discovery of
several synthetic insecticides, such as DDT, and herbicides boosted this
development. Chemical pest control is still the predominant type of pest control
today, although its long-term effects led to a renewed interest in traditional
and biological pest control towards the end of the 20th century.
termite or white ant, common name for a soft-bodied social insect of the order
Isoptera. Termites are easily distinguished from ants by comparison of the base
of the abdomen, which is broadly joined to the thorax in termites; in ants,
there is only a slender connection (petiole) joining these segments. In
addition, the antennae of termites are beadlike or threadlike, while ant
antennae are elbowed. Termites have chewing mouthparts. They feed chiefly on
wood, from which they obtain cellulose. In primitive species cellulose is
converted into various sugars by specialized gut protozoans and in the more
highly evolved termites by specialized bacteria living symbiotically in the
termite's digestive tract. Termites undergo gradual metamorphosis (see insect).
The nearly 2,000 species are mostly tropical, and some build huge mounds to
house their colonies. These mounds, up to 40 ft (12.2 m) high, are a
characteristic feature of the landscape in parts of Africa and Australia.
Termite Colonies and Castes
Termite colonies are composed of three castes; the reproductives (kings and
queens), the soldiers, and the workers. The kings and queens are sexually mature
termites, with compound eyes and fully developed wings. The workers and soldiers
lack wings and compound eyes. Sexually mature termites, or reproductives, are
produced in large numbers during certain seasons and leave the colony in a
swarm. They are poor fliers, and most are eaten by birds and other animals.
When the surviving termites settle, their wings break off along a weakened seam
at the base. They then form pairs, each of which establishes a new colony. A
couple excavates a chamber in wood or soil, in which they mate; they remain
permanently paired, and the queen eventually produces as many as 30,000 eggs per
day. Two or three weeks after mating, the young nymphs hatch and are fed on
liquid secreted by the parents and on fecal wastes, from which they obtain the
protozoan or bacterial symbionts essential for life.
The caste into which the young termite, or nymph, develops is dependent upon the
amount of growth-inhibiting substance (a pheromone) passed to it during feeding
and grooming. The pheromone is secreted by the reproductives and, when present
in a high enough concentration, prevents the development of nymphs into
reproductives. (A large colony may have several pairs of reproductives.) As more
workers and soldiers are added, since they do not produce the pheromone, its
concentration in the colony is correspondingly decreased. Therefore when the
colony reaches a certain size, some of the nymphs begin to develop into
reproductives, which then produce pheromones. This phenomenon also occurs if the
original reproductives die. The increase in the pheromone level prevents the
maturation of additional nymphs into reproductives; these remaining nymphs then
become workers. In a similar way, the appearance of soldiers appears to inhibit
the production of more soldiers.
In some families of termites, no workers develop, and the nymphs perform worker
functions, which include feeding the royal couple, the soldiers, and the very
young nymphs; caring for the eggs; grooming the queen; constructing and
repairing the nest; and foraging for food. The soldiers have heads as large as
the rest of the body and equipped with strong mandibles used in defense of the
colony. They attack any intruders to the colony and stand guard at the
entrances, in some species closing the entrances by putting their heads in the
holes. Soldiers of certain species squirt a sticky, poisonous secretion at
enemies.
Damage by Termites
There are two major groups of termites, the wood dwellers (family Hodotermitidae)
and the soil dwellers (family Rhinotermitidae). The latter cause over $250
million loss per year in the United States alone. The Formosan termite, a more
aggressive species than the U.S. species, was discovered in the United States in
1965 along the Gulf and in Atlantic port cities. Soil dwellers attack only wood
that is in contact with the ground or close enough to be reached through
enclosed earthen runways, which are connected to the termite's underground
galleries. Treatment of soil, use of treated wood, or shielding with metal and
concrete are among the methods used to prevent entry of termites into buildings.
Drywood termites do not require as high a humidity as do soil dwellers and will
attack trees, fence posts, stumps, and wooden buildings.
exterminator - someone who exterminates (especially someone whose occupation is
the extermination of troublesome rodents and insects)
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