2013-10-11 14:56:10 -
âTermites are a bane to human existence
Of the 2,300 species of termites known to exist in the world, only 183 are known to cause damage to structures, and of these, 83 have a significant economic impact!
Subterranean termites account for about 80 percent of the economically important species, and the genus Coptotermes contains the largest number of economically important species. Many thousand dollars are spent annually to combat these inconspicuous creatures. Control of subterranean termites and repair of their damage in the United States results in a total economic impact of about $6.0 billion per year. These Subterranean termites attack untreated wood and some also attack live trees. They are a huge problem in moist, warm climates along the western,
southern, and southeastern coasts of the continental United States and in subtropical and tropical locations of the United States and its protectorates and possessions. They pose a significant hazard to the numerous Eucalyptus trees planted as ornamentals, as windbreaks, or for fiber.
They are the cause of great economic losses of timber and related services all over the world especially in Australia. Only a few of the more than 300 species found in Australia are responsible for structural timber damage. In the Australian Capital Territory (ACT) region there are approximately 30 kinds of termites, although only a few cause extensive damage to sound timber. The two species that do most damage are Coptotermes frenchi and Nasutitermes exitiosus. Nasutitermes exitiosus are also associated with trees. Coptotermes frenchi and Nasutitermes exitiosus can establish nests if winged adults discover a damp area in the house, such as a shower recess or where the hot water system has leaked. They survive in places where water is readily available.
Nasutitermes exitiosus species is found most predominantly in southern Queensland and across most of the southern states of Australia. It is easily recognizable because, unlike other termite species, it has a dark pointed head, which makes it stand out. Nasutitermes exitiosus builds a mounded nest that is generally between 250mm and 700mm high. Their nests are generally found under decks and in sub-floors areas. They can cause a huge amount of damage to most wooden structures, especially hardwood fences, posts and sub-floors places where the timber is in direct contact with the earth or if the wood is damp or rotting. While this species is not as destructive as other termite species, left to their own devices they can still cause some serious problems. They are more of a problem for older homes that have not been well maintained where the timber has become wet. Interestingly this termite species has its own qualms regarding food. They do not like pine varieties, preferring the sapwood of hardwoods.
Defensive behavior of these termites was observed by scientists from Cornwell University, NY. The termites were confronted with live enemies like ants and other arthropods. It was observed that both soldiers and workers take part in the defensive actions. The weapon of destruction of the soldier termite is a spray from its frontal gland which causes irritation and has the capacity to hinder the mobility of the ant. The soldierâs secretion is an effective alarms pheromone. Once a target has been sprayed, the other soldiers converge around it. Attraction is effective around 30mm. The worker termites have no special weapons, but they can effectively bite. Ants may be crushed by the bites, or they may be slowed down by workers clamped to them with their mandibles and thereby rendered more vulnerable to being sprayed by soldiers. The substance in the secretion responsible for the alarm response remains unknown. The workers are essentially unalarmed by fresh secretion. Recruited soldiers tend to remain longer beside a "lively" sprayed enemy than beside one that has already ceased moving. It is suggested that in nature, sprayed incapacitated enemies might be covered over by the workers with feces and soil, a behavior that could bring about a timelier blockage of the alarm signal.
Nasutitermes exitiosus is almost invariably a mound builder in Canberra. If N. exitiosus is found it is likely there is a mound within 30-50 meters of the infested area, often in adjacent bush land. Nasutitermes exitiosus nests when opened have a distinct and characteristic odor which is thought to be associated with repellant exudates from the fontanelle at the tip of the nasus.
Another important species of termites which pose a threat to wooden structures are the widely infamous Coptotermes Frenchi. They can be found right down the east coast of Australia but are predominantly found in New South Wales and the Australian Capital territory (ACT) in particular, where it is rated as the most destructive termite species in the area. Coptotermes frenchi distribution extends from north Queensland to Western Australia in eucalyptus communities. Coptotermes frenchi has also become established in New Zealand, most likely introduced from Australia in imported logs.
They may travel underground up to 70m from the colony in search of food. They are particularly partial to eucalyptus and as such are commonly found in urban areas where eucalyptus is abundant. In the ACT many houses have pine or Oregon softwood frames, a favorite of this species. Because these subterranean termites can infest numerous tree species and wood in use, the presence of an acceptable host is not the critical factor. Rather, a suitable environment with an adequate supply of wood and appropriate temperature and moisture conditions are the key factors to their survival and proliferation. The initiation of a colony is a slow process, but wood in ground contact, moist wood in structures, and suitable host trees with scars or wounds at ports and storage facilities may provide an infestation site. The adults (alates) fly only about 100 m, but are capable of moving up to 1 km depending on wind conditions and weather.
These subterranean termites are highly destructive. Soldier termites produce milky liquid from a gland on their head when disturbed. Coptotermes frenchi is responsible for major damage to buildings, fences, posts, stumps and eucalypt trees. It is common for this species to devour timber framing leaving only a thin veneer. This species is the most shy of the destructive species; they will retreat from a location immediately (for the time being) if disturbed. They hollow out the upper part of the tree trunk. They feed on a range of timbers.
Nasutitermes exitiosus is almost invariably a mound builder in Canberra. If N. exitiosus is found it is likely there is a mound within 30-50 meters of the infested area, often in adjacent bush land. Coptotermes frenchi mostly nest in old eucalypt tree trunks. If these termites are detected, all large eucalyptus trees (trunks greater than 30 cm in basal diameter) or stumps within 60 meters should be checked. One indication of termite activity within trees is the presence of hollow broken branches. This is only indicative and a more reliable method is to test by drilling the tree. A drill auger (not larger than 19 mm diameter) should be used to bore holes towards the centre of the tree. If termites are present the centre will be hollow or filled with âmudgutsâ and the auger will suddenly penetrate the tree easily. A thermometer may be used to determine if the nest has been located. Nests are a constant temperature of 300 deg Celsius. The installation of barriers, either physical or chemical, has also been used as a method to prevent termites from entering buildings.
Considering the potential for damage that these termite species have exhibited a reliable method to combat them needs to be devised. C Tech Corporation has come up with such a novel product in the form of Termirepel˘. Termirepel ˘ is a non-toxic, eco-friendly and completely non-hazardous termite repellant which is effective against even the most aggressive and destructive termite species like the ones encountered above!!
Termirepel˘ works by the mechanism of repellence by virtue of which it does not allow the termites to come near the application and thus it negates the possibility of an infestation. The product is designed to not only counter the termite menace but is also effective against a host of other insects and pests. Termirepel˘ can be applied over wooden articles in the form of a lacquer or finish. It is approved by NEA (National Environmental Agency) for use on wooden articles.
If Australia is to be protected against the vicious Nasutitermes exitiosus and Coptotermes frenchi Termirepel ˘ is its best bet!!