The whole publication in PDF - Culture in Development

thigmotactic, meaning that they like to be in contact with a surface o n all sides of the body; they seek very small
crevices, between framed objects and the wall, etc. (Lindblom Patkus, 1999).
7.3.2.1 Silverfish and firebrats
Silverfish and firebrats are among the most ancient of insects. They were present on earth before insects developed
wings. These pests were among the most common insects in homes and businesses when wallpaper was the usual
wall covering and when coal furnaces had glued, taped and insulated pipes.
The silverfish and the firebrat are the most common representatives of the bristletails. Pest bristletails are about
1/2 inch long when adult and, unlike other insects, they continue to moult and may shed their exoskeletons as many
as 50 or 60 times when full-grown. They have long antennae in the front and three antenna-like protrusions on the
abdomen (the bristles of the b ristletails). They are slender, broadest in front and gradually tapering toward the rear.
In general, they shun light and prefer dark, undisturbed sites. The scientific name for the common silverfish is
Lepisma saccharina.
Firebrats are not silvery but mottled dark grey and dull yellow. Their distribution, size, shape and appendages
are like those of silverfish, but firebrats prefer decidedly higher temperatures and surroundings that are 90�F or more.
Examples of firebrat habitat are bakeries, where heat and starches are prevalent; furnace rooms; steam pipe tunnels;
hot apartment bathroo ms; and partition walls of water heater room s.
7.3.2.2 Cockroaches
Cockroaches have survived for more than 300 million years. Ancient cockroach fossils have the same appearance
as today’s cockroaches: oval and flat with long legs and antennae. The modern cockroach has the same need for a
warm, moist climate. Worldwide there are 3,500 kinds of cockroaches. Though most live wild in the tropics, a few,
called urban cockroaches, prefer the even temperature and moist conditions that humans maintain in their homes
and workplaces. Knowing similarities among and differences between species is important. Communicating this
knowledge will give clients more confidence in the professional ability of their pest controllers. By considering the
habits, the applicator can consider effective measures to control cockroaches. Except for size, all cockroaches are
relatively similar in overall shape and appearance. They are nocturnal and stay in the dark whenever possible. When
they are seen in the open or in the light, it usually means that a large infestation is present. Cockroaches also like
tight hiding places where their bodies can touch surfaces both above and below. As they grow to adulthood, they
will seek varied living spaces to accommodate their increasing size. Cockroaches are particular about where they
live – they do not uniformly infest one room or all rooms. The three most common cosmopolitan cockroaches are
the German cockroach (Blatella germanica), American cockroach (Periplaneta americana), and the Oriental
cockroach (Blatta orientalis).
7.3.2.3 Termites
Termites belong to the insect order Isoptera. In nature, termites are considered beneficial because they break down
dead and dying plant material. It is when termites feed on wooden structures that they become pests. Three types
of termites occur: damp, dry wood and subterranean termites. Subterranean term ites nest in the soil from which they
obtain their moisture. They may attack any wood in contact with the soil. If there is no direct wood to soil contact,
the termites may build mud tubes or tunnels within the cracks of foundations or over the outside of concrete to reach
wood several feet above the ground. To a limited extent, termites are capable of regulating temperature conditions
in the colony. Their galleries often are situated so that some run above ground and some below. Therefore, during
extremes of hot and cold weather, the termites will be found below the ground where the conditions are more
equitable. Subterranean termites ne ed a constant, ample supply of mo isture. Part of this m oisture is procured from
the products of their own metabolism and part from soil moisture, which diffuses throughout their tunnels or tubes.
Since the subterranean termite colony usually obtains its moisture from the soil, they are generally dependent on
soil types. Moisture in clay soils is tightly bo und to the particles and not readily available to the termite. Sandy soils
allow more moisture to be available and, consequently, these termites are more prevalent and able to survive in
sandy soils. Fungi, when present in the wood, will serve as another source of moisture. These fungi aid in the
regulation of humidity in the galleries. The plugs of partially chewed food and faeces placed by the termites in the
passages also assist in moisture regulation. Occasionally, subterranean termites can be found above ground, isolated
from the soil. This can occur if moisture is available from a source other than the soil. Common sources include
condensation, and leaking pipes and roofs. Wood is made up primarily of cellulose, a large complex chain of
relatively simple chem ical molecules. Few animals have the necessary body chemistry to break down cellulose into
smaller, more usab le nutrients. Termites accomplish this by the p resence of protozoa in their hindgut rectum. These
protozoa break down the cellulose into products that the termites can digest. If these protozoa are removed, the
termites will eventually die of starvation.
7.3.3 Roden ts
7.3.3.1 Rats
Rats, in particular have caused more hum an suffering and more eco nomic damage than any other vertebrate pest,
from causing plague epidemics, the Black Death of Europe, to rat-bite fever. Statisticians estimate that rats destroy
20 percent of the world’s food supply every year, directly by feeding and indirectly through contamination. Rats
gnaw constantly and their teeth are extremely hard. They com monly chew through building materials such as cinder
block, aluminium siding, sun-dried adobe brick, wallboard, wooden cabinets, lead sheathing, and plastic or lead
pipes. After gnawing a hole, an adult rat can compress its body and squeeze through an opening only 0.5 inch high.
In most instances, rats are very wary. Their control requires an integrated approach tha t includes non-lethal tools
such as careful inspection, upgraded sanitation, and rat-proofing structures. Lethal control often combines the use
of rodenticides, any substance that is used to kill rodents, with non-toxic control measures such as snap traps or glue