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Termites are social insects belonging to
the order Isoptera. They are closely related to cockroaches.
They are different from almost all other insects in that
they can utilize the cellulose of wood. Termites are able
to do this because of single-celled organisms that live
in their digestive tracts. These organisms, protozoa and
bacteria, help convert the cellulose eaten by the termites
into sugars which the termites can then utilize.
Each time the termite molts, the chitinous lining of the
digestive tract is shed along with the rest of the exoskeleton.
The protozoa and bacteria are lost in this process; because
termites are dependent on the protozoa and bacteria to survive,
the recently molted termite must then replenish its system
with these important organisms. The termite does this by
obtaining a small droplet of anal fluid, containing bacteria
and protozoa, from another termite in the colony. Many people
believe that it was this need to obtain more bacteria and
protozoa after each molt that led termites to evolve as
social insects living in colonies. It is important to note
that any process that kills the bacteria and protozoa of
the termite will also kill the termite.
In nature, termites are valuable decomposers because they
help convert dead wood and other cellulose materials into
humus. When humans began building structures of wood, termites
naturally infested these structures and utilized them as
a food source. Some other kinds of insects such as powder
post beetles, old house borers, and the wharf borer "eat"
wood; but most cannot digest the cellulose and, therefore,
must get their nourishment from the starch and sugar that
the tree stored in the wood cells. To these insects, the
cellulose itself has no food value and is thus excreted
from their bodies as wood pellets, powder, or "frass." Still
other insects such as carpenter ants and carpenter bees
get no food value whatever from the wood and simply excavate
holes and cavities in the wood to provide protective shelter
for their offspring. The wood particles removed are not
swallowed, but simply discarded.
Subterranean or ground-nesting termites, Reticulitermesflavipes
(Kollar), and, rarely, Reticulitermes virginicus (Banks),
are by far the most destructive insect pests of wood. They
attack buildings and other wood products in all states except
Alaska and are most common and cause the most destruction
in the warmer regions. (Figure 1)
Figure 1
In New York State subterranean termites are most abundant
on Long Island and in the southern counties adjacent to
the Hudson River. they are present in other parts of the
state as well (Figure 2)
Figure 2
Importance
The subterranean termite of the northeastern
states are native soil-dwelling insects that feed on wood,
paper, and other materials containing cellulose. In the
forests, these termites are beneficial because they help
decompose fallen trees and stumps and return the wood substances
to the soil to be used again by other trees as part of the
nutrient cycle. The economic importance of the subterranean
termite with regard to buildings arises from the fact that
the wood members of a building closest to the soil, and
therefore the most likely to be severely damaged by the
termites, are usually the sills, joists, studs, girders,
and other important load-bearing elements of construction.
Failure to stop termite attack can result in such loss of
support that other forms of building deterioration, such
as sagging walls and damaged doorframes can occur. Heated
buildings whose construction places wood in close proximity
or actually in direct contact with the soil offer termites
the ideal environment: a favorable year-round climate and
an abundant sheltered food source. Sometimes wooden buildings
that are unheated in the winter, such as barns, stand for
decades without any serious termite infestation. However,
when such buildings are remodeled into homes, studios, etc.,
and supplied with heat, serious termite damage often follows
in a few years.
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