History of Pest Control & Termite Protection In Australia
Termites and Buildings
It is conservatively estimated that termites infest and cause damage to 1 out of every 5 houses in Australia. This ratio includes houses in Melbourne and Sydney and Perth where the incidence of termite infestation is much lower than that which occurs in the warmer subtropical and tropical areas of Queensland. Furthermore, destructive species (Schedorhinotermes. SPP in the S E QLD area and Mastotermes in the tropical north) of termites are prevalent in Queensland that are nonexistent or very rare in the Southern Sates, this means that a termite infestation in Queensland can be much more serious issue than it might be in Sydney or Melbourne. Contact Townsville pest control if you believe you have a risk of an infestation.
Older “Queenslander” style houses and the new slab on ground construction
Before the invention and widespread use of chemical pesticides during the 1950s houses in termite prone areas like Queensland were built to minimise the risk of termite infestation by raising the floor high off the ground using piers made from termite resistant timbers. This gave rise to the style of house called the “Queenslander”. Steel caps (ant caps) were placed on top of the piers to force the termites to make large mud structures over the caps before they could gain access to the house. Home owners regularly poured sump oil around the base of the piers and were easily able to inspect for signs of termites as they were able to walk freely around under their house.
During the Late 1950s and early 1960s builders realized that these new pesticides we so effective and long lasting that it would be possible to build houses in Queensland with concrete slabs poured on top of a layer of pesticide and that these houses presented little risk of termite infestation. The chemicals used we called Organic Chloride and they had the advantage of crystalising in the soil structure and remaining active and effective termite barriers over very long periods of time. The new style Slab on Ground style homes were superior in many ways to the old timber floored homes and the added advantages were that they were cheaper, faster and easier to build. Pretty soon everyone stopped building the traditional Queenslanders and hundreds of thousands of the new slab on ground houses were built.
The dangers of Organic Chlorides discovered
During the 1970s and 1980s disturbing facts were beginning to emerge regarding the unwanted side effects of these Chlorinated Hydrocarbons(Organic Chlorides) to people and the environment. Widespread use of their use in agriculture and industry were phased out first and slowly during the early 1990s successive pesticides were withdrawn from use in Queensland until in 1995 the last remaining organic chloride chemical was withdrawn for the protection of buildings in Queensland.
The building industry was in unenviable position even if they had the skills to build the older style Queenslander homes the public were demanding the cheaper slab on ground style homes for a few years the only protection available to homes was the very ineffective Organic Phosphate Chemicals some newer unproven synthetic pyrethroid chemicals and a hugely expensive stainless steel mesh to replace the pesticide barrier under the slab.
The re-emergence of termites as the largest risk to homes
Because of the effectiveness of the organic chlorides a whole generation of homeowners never had to give a second thought to the dangers of termites to their home and now the new homes being built were not only lacking a reliable termite barrier but the knowledge of how to reduce the risk of termite infestation to homes had been lost from the general publics awareness.
New methods of protection
New methods of deterring termites had to be introduced and many new products were introduced to the market, even today the industry is still trying to reach the previous levels of protection from termite infestation that the older style pesticides provided and the unfortunate fact is that it’s probable that we will never see another method that will be as effective and maintenance free as the old Organic Chloride chemicals.
The Monolithic slab
Probably the most important development since 1995 is the adoption of forward thinking home builders and designers of the “monolithic slab design”. In this design the slab floor is poured in one piece on top of the ground, all the penetrations through the slab are sealed to prevent termite entry and the entire perimeter of the slab edge is visible.
Theoretically the slab itself forms an impenetrable barrier to termites. Any termites gaining access to the building are easily betrayed by the presence of mud shelter tubes on the exposed slab edge.
It is important to remember though that as good as this development was is still has many serious shortcomings. Most importantly:
- At least 75mm of the slab edge must be visible around the entire perimeter of the building
- Although the slab is design to resist cracking under normal conditions any soil movement under the slab may cause it to crack
- The system does not prevent termites from accessing the home over the exposed slab edge
- The system does nothing to deter termites
- The system is easily compromised. (for instance by covering the slab edge with a garden bed)
- The slab edge needs to be regularly inspected for signs of termite attack
Other important developments
Following the relative success of the monolithic slab important innovations have been developed these are:
- Non repellent termiticides
- pre-impregnated termiticidal blankets
- Termite interception and colony elimination systems.
Just as the changes in construction methods from the “Queenslander” to the slab on ground style home has provided challenges to the way we protect our buildings from termites these changes have also presented many challenges and limitations to the inspections of homes for termite activity. To compound this problem Insurance companies are very specific about the wording and limitations that are required in any report. Any termite report that does not contain these limitations has undoubtedly been prepared by someone who is either uninsured by choice or uninsurable due to their lack of qualifications or previous negligence.
Termites are secretive by nature and often only the slightest signs betray their presence. In Australia we are very lucky to have some the world leaders in termite detection and inspection. These respected industry experts produced two Australian Standards dealing with termite and timber pest inspections. These are:
- AS4349.3 Inspection of buildings Part 3 Timber pest inspections
- AS3660.2 Termite management Part 2 SECTION 3 Inspection and detection
A termite inspection carried out by a suitably qualified person following the guidelines and using the equipment specified in either of these Australian Standards will alert the property owner to any risk areas and report on the presence of termites in the house to the extent that it would be reasonable to expect that a qualified and competent inspector would be able to discover them.
In Plain English this means that although there are limitations to the report the information contained in the report is based on the careful and diligent observations of a qualified person following the guidelines of the most experienced and knowledgeable people in Australia and although the report has limitations it does not in any way absolve the inspector from not reporting on any risk or termite activity that would be discoverable by a qualified person following the guidelines set out in the Australian Standards
Biological Control in Australia
Australia has a long history of attempted biological control of pests. The results of these vary from amazing successes to catastrophic failures.
Cats Released to Stop Rabbits
In the 1890’s 300 Cats were released in the west of South Australia in an attempt to stop the Rabbits invading Western Australia.
It definitely did not stop the Rabbits. The people who released them must have been optimists if they expected 300 Cats to stop the advancing plague of Rabbits.
Some of the Cats would have starved. Some would have gone wild, contributing to the population of feral Cats. No doubt the Cats did kill a few Rabbits, but they would also have had much more effect in killing the young Goannas and other potential Rabbit predators, so the Cats would have contributed to the survival of the Rabbits.
European Carp were released by the government into the River Murray to control the plants growing there. This attempt was successful. The introduced Carp did eat a lot of Native water plants. Unfortunately they also did enormous damage to the river’s ecosystem. Now Carp are a major problem in the river, and governments are looking at ways of controlling them.
Carp have seriously disrupted the Ecosystem of our biggest river system. In planning control methods we need to consider the effect on the whole ecosystem.
Mosquito Fish, Gambusia affinis, and its relatives were introduced by the government to control Mosquitoes. This was a dismal failure. The Mosquito Fish is a poor eater of Mosquito Larvae. Instead it has severely reduced the numbers of native fish which were good predators of mosquitoes. It is now illegal to possess Mosquito fish in many areas.
A moth, Cactoblastis cactorum, was introduced in 1926 to control the introduced Prickly Pear. This is described in more detail in the article about Prickly Pear.
This was perhaps the greatest success of all biological control attempts anywhere in the world.
The moth had been extensively tested to make sure it would not harm any Australian native plants.
Sugar Cane growing in Australia was being attacked by two native beetles, the Greyback Cane Beetle, Dermolepida albohirtum, and Frenchi’s Cane Beetle, Lepidiota frenchi.
The Cane Toad is native to the central portions of the two American continents. It had been introduced to Hawaii to control scarab beetles in Sugar Cane. Apparently it was successful at this.
Despite protests in Australia, the Cane Toad was released in the 1930’s after only about six months of controlled breeding and perhaps testing.
The Cane Toad is now a major pest in Australia. No one appears to have even studied how successful it is in controlling the native pests it was introduced to eat.
Personally, I wonder if the amazing success of Cactoblastis was one of the reasons for the shortness of the period of testing the Cane Toad. Another thing I wonder about is what sort of pressure the scientists testing the Cane Toad were under from government and business.
Biological Control of the Cane Toad
Now, having introduced the Cane Toad for biological control, scientists are looking at controlling the Cane Toad.
It was believed that all the parasites of this Toad had been left behind, but careful analysis was done of a lung worm attacking the Cane Toad. This parasitic nematode worm turned out to be Rhabdias pseudosphaerocephala. This is a South American species and is different from the similar looking worms attacking native frogs.
This worm kills about 30 percent of the Cane Toads, and the ones left are much smaller than unaffected Toads.
The Cane Toad is spreading rapidly across tropical Australia. The bigger toads move faster. This means that the parasite is being left behind. One option is to take the parasite to infect young toad tadpoles at the front of the spreading toad plague. If this parasite had not been accidentally introduced it would have had to be extensively tested before release. If it could have infected native frogs, it could have caused serious problems of its own.
Native Meat Ants are a major predator of Cane Toads. Simple ways have been found of increasing their effectiveness.
Biological Control of Rabbits
One feeble attempt to control Rabbits with Cats is mentioned at the start of this article. The introduction of Foxes to Australia was not an attempt at the Biological control of Rabbits. It was done about 20 years beforethere was a Rabbit problem on the mainland. However, some of the secondary introductions might have been done in a misinformed attempt to control Rabbits.
In the late 1940’s, or possibly in 1950, Myxomatosis was introduced to Australia to control Rabbits. This disease kills Rabbits slowly and with considerable suffering. In 1963, the New Zealand government decided not to introduce this disease to their country.
The head of the Victorian Royal Society for the Prevention of Cruelty to Animals in 1985, Peter Barber, stated that the public outcry against introducing this disease in 1985 would have prevented its introduction. Attitudes had changed in the previous 40 or so years. There were protests even in the 1940’s against the introduction.
Myxomatosis was successful in getting a temporary major reduction in the numbers of Rabbits, but the numbers have built up again. There is very strong selective pressure on the Rabbits to evolve resistance to this disease in Australia.
The longer term effect of Myxomatosis may have been less favourable. Foxes and Cats no longer had so many Rabbits to eat. They ate more native animals, including the young ones of good Rabbit predators. To set against that effect, there was chance for some regeneration of vegetation which would have been good for native animals.
However; we still have an ecosystem in much of Australia dominated by Rabbits, Foxes, Cats and introduced grazing animals. In fact the domination of the introduced predators appears to have increased since the introduction of Myxomatosis. In that sense it was a total failure. In fact people have argued that it actually was responsible for the increased domination of these three species.
The use of native predators for Rabbit control is usually not considered. However, encouraging native Rabbit predators like Goannas is much less likely to cause permanent harm than introducing a species from another continent. The Goanna population has been seriously damaged by Foxes and Feral Cats eating the young Goannas. The only place I know of where they killed all the Rabbits is on Kangaroo Island where there are no Foxes.
Probably better than just one predator being deliberately built up would be the encouragement of a range of them. Wedge-tailed Eagles are a major Rabbit predator, but they were killed in the millions in the mistaken belief that they kill a lot of lambs. Quolls, especially the larger ones, are also good Rabbit predators. These have been greatly reduced in numbers by Foxes.
Related to this disease was the introduction in 1969 of the Rabbit Flea to help spread the disease.
Rabbit Haemorrhagic Disease appeared in China in 1984. Together with many other agents this Rabbit disease was considered for importation to Australia.
In 1991 it was brought in. It was tested under strict quarantine in Geelong. This program was jointly funded by the Australian and the New Zealand Governments.
In March 1995 testing in a fenced enclosure at Wardang Island was commenced. Wardang Island is 4 Kilometres off the coast of Yorke Peninsular in South Australia’s Spencer Gulf. This island already had wild Rabbits, and had been used for testing Myxomatosis.
The testing in Geelong had suggested that the fence would be sufficient to prevent the disease getting into the wild population of the island. However, on October the 1st 1995, it was realised that the wild population of the island was infected. In accordance with the procedure originally worked out, the decision was made to exterminate all the wild Rabbits on the island.
But on October the 17th 1995 a Rabbit victim of the disease was found at Point Pearce on the mainland just opposite Wardang Island.
This is an extraordinary rate of spread.
How it Escaped
Of course, we do not really know how it reached the mainland so quickly. The official belief is that it was carried by an insect like the bush fly. Bush flies do not generally fly out to sea, but there are a lot of them. It is likely that some are carried by the wind the 4 Kilometres to the mainland.
The official story is widely disbelieved in Australia. Many people think that it was spread by a Human with malice aforethought. That is, malice towards the wild Rabbits.
Before the release there had been public speculation that the government would decide not to release the virus.
As I said, we do not know how is got out. Either the scientists who set up the conditions of the experiment got it wrong, or a Human was involved.
Rabbit Haemorrhagic Disease was renamed Rabbit Calicivirus. It was stated that death from this disease involved much less suffering than death from Myxomatosis. On average death is faster but people disagree about how much the Rabbits suffer.
In Australia the decision was never made by the government to release the virus. Any public consultation was rendered irrelevant by the premature release. Potentially this release was very dangerous because testing had not been completed.
As far as is known, Rabbits are the only animal that can get sick from Rabbit Calicivirus. Even Hares appear to be immune. Caliciviruses of other types infect many other species, including Humans. There is no evidence that it is likely that the Rabbit Calicivirus will cross the species barrier. It seems that we were lucky in this case.
The Rabbit Calicivirus is killing large numbers of wild Rabbits. However, it is very much less effective than it would have been if testing had been completed and a proper plan worked out for its release.
Like Myxomatosis Rabbit Calicivirus is reducing the numbers of Rabbits but proper management of the whole ecosystem needs to be done. If Rabbits cannot be exterminated they need to be managed on a permanent basis.
In New Zealand careful consideration was given to importing the Rabbit Calicivirus. It was decided not to bring it in. In 1997 it appeared in the country. It is almost certain that this was done deliberately. The antisocial criminal responsible has not yet been caught.
It was deliberately spread by people who did not really know what they were doing and was very much less effective than it could have been.
Although only a few examples of biological control have been given here, it would appear that introducing any organism from overseas needs to be done with extreme caution. Using native organisms is less likely to permanently disrupt the ecosystem.