Objectives
TERMITES (Macrotermes bellicosus)
Phylum: Arthropoda
Class: Insecta
Termites are social insects commonly known "white ants".
Social Insects
Social insects are groups of insects which live together in a colony where there is division of labor among members or castes. Other social insects are ants, honey bees and wasps.
Features Common to Social Insects
Termite Habitat
Termites need a source of moisture to survive. In temperate habitats, they are found in decaying woods, and in the soils. Termites are found in dark, damp areas whereby they are not exposed to sunlight.
Structure (Characteristic Features) of Termites
A typical colony contains workers, soldiers, and reproductives. Their body is divided into three parts head, thorax and abdomen. The head bears a pair of short antennae and mouth parts. The thorax bears three pair of walking legs.
Characteristics of Worker Termites
They are smallest and the most numerous of the castes.
They are made up of male and female termites, with no sex organs, no eyes and no wings.
They have brown head with chewing mouthparts and a pair of antennae.
Function of Worker Termites
1. provide food for the colony and nurse the nymph
2. dig tunnels
3. build and repair the nest
4. groom the queen
Characteristics of Soldier Termites
Soldier termites are yellow brown in color. They have a large head with powerful jaws/mandibles.
They are blind, wingless, and sexually immature. The thorax bears three pairs of walking legs.
There are two types of soldiers:
1. Mandibulate soldier: have large hardened head with powerful jaws.
2. Nasute soldier: have round head that protrudes out to form a sharp point.
Functions of Soldier Termites
They defend the colony against invaders. The mandibulate soldier used the head to block narrow tunnels and snaps with their strong jaws against intrusion of ant. The nasute soldier produce a poisonous sticky substance to entrap their enemies.
Reproductive Termites
(The winged or "alate" castes)
They have reproductive organs, eyes, two pair of wings, and 3 pairs of legs.
The wings break off after nuptial flight and remain wingless. Two reproductive termites become king and queen. The queen later becomes largest member with king being the second larger. The mature queen has an enormous white abdomen with clear spiracles on the sides.
Functions of Queen and King
1. The queen duty is solely eggs laying
2. The king mates with the queen to fertilize the eggs
Structure of termites Mound or Nest (Termitarium)
The nest provides a protection and water conservation.
Mode of Life of Termites
Nutrition in Termites
Termites eat cellulose in its various forms as plant fiber. Cellulose is a rich energy source, but remains difficult to digest. Termites rely primarily upon symbiotic protozoa such as Trichonympha in their guts to digest the cellulose. This process of digestion only takes place in the worker. The food is then regurgitated to feed other members of the castes.
Termites also practice fungi-culture. They cultivate fungal gardens that grow on plant matters, providing a nutritious mycelium on which the colony then feeds.
Life Cycle of Termite
Early in the rainy season, mature reproductive termites leave and swarm. They emerge in their numbers from the parent nest and fly off to establish new colonies. This flight is term as “nuptial flight” or “colonizing flights”. During the nuptial flight they rip off their wings and become the king or queen termites of a new colony.
Termites show incomplete metamorphosis. The queen lays fertilized eggs which hatch into pale, white larvae. They grow into one of the three colony castes: workers, soldiers and reproductive termites.
Economic Importance of Termites
1. They destroy crops by chewing or gnawing the bark of trees or roots of crops such palm oil, cocoa etc.
2. They destroy wooden structures.
3. They also damage paper, cloth and other cellulosic materials.
4. Some people feed on winged reproductive.
5. They aerate the soil by their burrowing activities.
6. Termite tunnels in the soil allow rainwater to soak in deeply and help reduce soil erosion.
7. Termite mounds provide a habitat for small animals such scorpions, lizards, snakes, etc.
8. They speed up decaying process, increasing humus content of the soil.
9. Soil from termitaria is used for tennis court.
10. Termites are used as poultry feeds.
11. Removal of termitaria increase the cost of mechanized farming and road construction
How to Control Termites
1. Woods meant for construction works, should be treated with termite repellents such as creosote or coal tar.
2. The earth round the building can be mixed with insecticides (e.g., B.H.C) to keep termites away.
3. Buildings should be constructed on solid concrete or steel foundation to prevent termites from getting access to the wood.
4. Use timber that is naturally resistant to termites, such as turpentine tree, teak in building.
5. Destroying covered tunnels of termites.
A daptive Features of Termites
1. Queen has large or swollen abdomen; which stores eggs.
2. Soldier (Mandibulate) has massive/large mandibles, large head to defend the colony or use of large head to block entrance of tunnel.
3. Worker termites have well developed mouthparts and legs; to carry out feeding, building nest and repairing the nest and collecting food for the colony.
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