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ISOPTERA Insecta: Order: Isoptera -- Clasification |
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Their cerci are short. Metamorphosis is simple.
They, like some Hymenoptera, have a social organization. Termites abound everywhere in the tropics
where they cause extensive damage to wood products. Termite Habitats The termite nests may be simply series of burrows in trees,
dry timber or in the ground, or they may be huge mounds made of earth
cemented together with the saliva of the termites. Those living in the ground
excavate the soil of the tropics, turning it over and enriching it just as
earthworms do in temperate regions. Others may remove permanently from the
soil much of its organic matter.
Their food consists mostly of wood and other vegetable matter and many
species are extremely harmful, e.g. Neotermes,
which damages human structures, and Calotermes militaris, which bores into and does much harm
to tea plants in Ceylon (Borradaile & Potts, 1958). Many species of
termites reduce dead wood to organic soil material and thereby make
agriculture possible in some areas.
However, termites are in competition with humans for wood through
their damage to buildings. They are
of greatest importance in warmer regions.
There are basically two types of termites: subterranean and dry wood.
Subterranean termites are soft bodied with a thin cuticle. They obtain moisture from the soil or
metabolic processes. They are more
organized than the drywood type. They
also modify their habitats by constructing tubes in their foraging activities
for food. Mounds, called termitaria,
are constructed in some areas. These
often reach heights of one or two meters, and they are oriented to a north
and south direction for heating purposes.
Nests are sometimes built in trees, although these are smaller. They may contain fungus chambers. Dry
wood termites confine their nests to the wood that they depend upon for
food. They are widespread and cause
considerable damage to wooden houses and the wood products contained therein
(chairs, tables, etc.). Nutrition
Termites usually forage by night for plant food, and members of the
subfamily Microtermitinae cultivate fungus gardens in special galleries. The fungus, which grows on a bed of
chewed vegetable matter, serves as the food for the royal pair and the
nymphs. Their principal food is
cellulose, which is digested by flagellated Protista symbionts (Zoomastigina) in their gut. These symbionts are passed on in two
ways: (1) regurgitated liquid food
and (2) excrement. Protein is
obtained by eating dead termites.
Digestion and growth of wood-eating termites can only proceed when
flagellate fauna occur in the hindgut. The fragments of wood are ingested by
the flagellates and converted into sugars, being for the most part stored in
the form of glycogen. The termite requires the metabolic services of the
flagellates to render the food available, and in return provides the
anaerobic conditions that the flagellates are known to require. Termite Castes
The
mandibles and head of worker termites are modified to produce enlarged forceps-like
mandibles, snout-shaped structures and plug-shaped structures. Some
of the more primitive termite species have only two castes: reproductives and soldiers. Immature individuals of these two castes
perform work in the colony. Termite
Reproduction When
conditions such as high humidity, light intensity, ample food and
overcrowding are present, wings are produced and functional males and females
develop. These leave the colony, and
the winged sexual forms in several colonies usually swarm at the same time,
so enabling intercrossing between members of different colonies to take
place, and of the immeasurable numbers, a few individuals escape the attacks
of birds and other animals and alight and cast their wings. The insects pair in flight and then drop
to the ground to seek a nesting site at the discretion of the female. They lose their wings, mating takes place
and unlike other insects, the male remains with the female and frequent
mating takes place. Soon after mating
the female loses all capacity other than egg laying, and a single pair forms
a new colony first of all by making a small burrow, the nuptial chamber. The first-formed young are mostly workers and,
having themselves been tended to maturity by their parents, take over the
nursing of the young. The queen becomes massive and helpless and is fed by
the workers; she lays eggs at an unbelievable rate of over one million eggs
annually. Termite Control
Eliminating termites from dwellings can be an expensive undertaking
especially if they are widespread within.
Tenting and fumigating is the usual procedure that is required by law
in some areas when houses are sold.
Nevertheless, this is not a permanent solution, as reinvasion will
inevitably occur. Spot treatment of
infested beams can be achieved with pressurized aerosol insecticides
available on the open market.
However, it is essential to penetrate the entire colony. Small blackish beadlike droppings below
infested beams are indicative of their presence somewhere above. Temperature influences their movements in
the beams: high temperatures cause
them to descend to lower, cooler levels and low temperatures cause them to
seek out warmer areas.
Preventative measures can be taken by shielding wood surfaces with
metal flashings, especially where these touch the ground, and by treating
outdoor wood with preservative chemicals (e.g., creosote).
Swarming by alate adults in the North American Southwest occurs during
late springtime. It is not uncommon
to see local lizards consuming them at a rapid rate as they emerge from their
colonies. Where the feeding is very
extensive it undoubtedly has a significant impact on the termite
populations. Also, the Argentine ant Linepithema
humile has been associated with declines in
termite populations in the Riverside, California area. The ants have been observed feeding on dieing
alate termites, but other associations are yet to be investigated to account
for reductions in the structure infestations Engel,
Michael S. 2008. Two New Termites in Baltic Amber (Isoptera). Journal of the Kansas
Entomological Society Vol. 81 (3):
194-203. Engel, Michael S., David A. Grimaldi & Kumar Krishna. 2009. Termites (Isoptera): Their Phylogeny, Classification,
and Rise to Ecological Dominance. American Museum Novitates Vol. 2009
(3650): 1-27. Grimaldi, David A., Michael S. Engel & Kumar Krishna. 2008. The Species of Isoptera of The Early Cretaceous Crato
Formation: A Revision. American Museum
Novitates Vol. 2008 (3626): 1-30. Helfer, J. R.
1987. How to know the
grasshoppers, crickets, cockroaches, and their allies. Dover Publ, New York, NY. 363 pp. Howse, P. E.
1970. Termites: a study in
social behaviour. London Publ. 150pp. Kalleshwaraswamy, C. M., H. B. Pavithra, A. S. Vidyashree & G. S. Sathisha. 2018.
Comparative Termite (Isoptera)
Diversity in Three Different Habitats of Shivamogga District, Karnataka,
India. Journal of Entomological
Science Vol. 53 (2): 219-229. Kofoid, C. A., et al.
1934. Termites and
Termite control. Univ. Calif. Press,
Berkeley 734 pp. Lee, K. E. & T. G. Wood. 1971.
Termites and Soils. Academic
Press, London and New York, 252 pp. Mallis, A. (ed.).
1997. Handbook of pest
control: the behavior, life history, and control of household pests. 8th ed.
Mallis Handbook & Technical Training CO.
Cleveland, Ohio. 1456 pp. Ratcliffe, F. N., F. J. Gay & T. Greaves. 1952.
Australian Termites. The Biology, Recognition and Economic Importance
of the Common Species. C.S.I.R.O.,
Melbourne, 124pp. and Partig, Liepzig, 309 pp. Triplehorn, C. A., & N. F. Johnson (eds).
2005. Borror and Delong’s
introduction to the study of insects. 7th Edition. Brooks/Cole Publishing, Kentucky, U.S.A. 868 pp. Wilson, E.O.
1971. The Insect
Societies. Harvard University Press,
Cambridge, Mass. 548 pp. REFERENCES: |
