Urban Australian cities under termite attack

There is an emerging huge cost to buildings and other wooden structures from termite damage in urban Australia. Concerns about the environmental and public health consequences of the large
quantity and frequent reapplication of termiticides (chemicals for the treatment of termites) in urban
Australia has led stakeholders to identify a need to have appropriate information that reflects local
conditions about their environmental and health effects.

There is an emerging huge cost to buildings and other wooden structures from termite damage

 

Introduction

Termites consume wood and cellulose in natural bush land and serve an important ecological
function by converting dead trees into organic matter. Unfortunately in the urban environment, the
wood in buildings and other structures such as wooden power poles and bridges is equally
appealing to termites and infestation can cause considerable damage.

 

 

During the 1999–2000 financial year, the Queensland Department of Housing spent $410,000 managing termite infestations in public housing. In the Ipswich, Woodridge and Capalaba areas in southeast Queensland, the estimated cost of repairs for termite damage ranged from $18,000 to $60,000 per property (Department of Public Works’ Built Environment Research Unit figures, September 2005).
On average, termite infestations cost approximately $1500 in treatment, and repairs of $5000 for
each building affected (Caulfield, 2002). It is estimated that 10% of Australian houses have had or
will have termite infestations, with that figure rising to 65% in some areas – a resulting per annum
cost of $4 billion (Caulfield, 2002). Management of termites, and eradication of exotic species is
also costly – a campaign to eradicate West Indian dry wood termite Cryptotermes brevis (Walker)
in Queensland is estimated to have cost $4.2 million by 1998 (Peters and Fitzgerald, 1998).
Worldwide, damage caused by termites is estimated at U.S $22 billion per annum in terms of
Urban cities & termite attack Environment 25– 3 damage to wooden structures (Fage et al., 1988).

Treatment and prevention of termite damage in Australian cities is therefore needed, and may give rise to unwanted side effects.
Until 1995, organochlorine termiticide treatments were used to create barriers to termites in
Australia. These have since been replaced with other, less persistent, chemicals and physical
barriers. As a consequence, chemical termiticides need to be reapplied on a regular basis, averaging
every 3 to 5 years depending on local conditions. There is a relative lack of knowledge of the
consequences of repeatedly using these replacement chemicals under Australian conditions. In 2005, bifenthrin (FMC Australasia Pty Ltd) is the most commonly used termiticide in Australia followed by imidacloprid and fipronil. Chlorpyrifos (Dow Agricultural Products) has decreased in use because of concerns over toxicity and efficacy in alkaline soils.
Permethrin, alpha-cypermethrin are not currently used even though they remain registered for use in
Australia by the National Registration Authority (NRA).

 

Termite Ecology

In Australia, the majority of pest termites are native (the exception is C. brevis).

Australia’s termite fauna is diverse, represented by five families (Mastotermitidae, Termopsidae,
Kalotermitidae, Rhinotermitidae and Termitidae) comprising 40 known genera and more than 266
described species. Termites play a key role in the nutrient cycles of tropical ecosystems (Whitford,
1991). Termites may be grouped as damp wood, dry wood or subterranean, depending on their
habits. Damp wood termites live in rotten wood, particularly in logs or in damp sections of trees and
are rarely considered to be of economic concern. Certain dry wood termites are of economic
importance, with the exotic West Indian dry wood termite C. brevis identified as the most
destructive species (Peters and Fitzgerald, 1998). Subterranean termites are those that require
contact with the ground or moisture and they are responsible for damage to timber structures in
buildings and in trees.

 

Termite Management in Australia

In Australia prior to 1962, arsenic dusting was the most common means of small-scale termite
management. Nests were located and dusted directly with arsenic trioxide powder. Before 1995,
subterranean termite management in Australia was based on the use of the highly persistent
organochlorine insecticides ( Peters & Fitzgerald, 1988), such as aldrin, dieldrin, chlordane and
heptachlor (known collectively as cyclodienes, because of their particular chemical structure),
which were well suited to slab-on-ground housing construction. Because of their chemical stability,
they were extremely effective Australia-wide, and had no immediate adverse health effects at the
levels of exposure arising from the approved use. Owing to environmental and public health
concerns associated with their persistence in the environment and their tendency to accumulate in
the fat of animals and humans, these chemicals were withdrawn from the market in 1995 and
alternative strategies for termite management have been developed.

Currently in Australia, we may be enjoying a period of overlap where older buildings are still being
protected by the organochlorines while new structures have been treated variously with
organophosphates (chlorpyrifos), pyrethroids (bifenthrin) and imidocloprid. Houses built before
1985 may still be protected to some extent by the organochlorine termiticides applied to the soil
during construction. However, the effectiveness of the residual organochlorines will have been
reducing over time (possibly up to 20 years although there is no reliable Australian data), and older
houses may be at risk of termite infestation. The potential costs of re-treatment and repairs are
likely to increase dramatically in the future as older slab-on-ground dwellings become susceptible
due to the eventual failure of the organochlorine termiticides.

 

Chemical Termite Management in Australia

The withdrawal of the organochlorines as termiticides in Australia has by necessity encouraged the
introduction and investigation of new products and methods for termite management. Previously, because the organochlorines were so effective, there was apparently little
commercial incentive to develop new chemicals or barrier controls. Chemical control can be
divided broadly into preventative and curative measures. New buildings are treated with a chemical
barrier beneath and surrounding their slabs. Where access to slabs is not practical for under-slab
termiticide application, reticulation systems can be installed pre-construction, enabling repeated
application of termiticides over time. Where a termite infestation has occurred, chemicals may be
applied as spot treatments, sprays, baits or gases. There are termiticides registered for use in
Australia as varying formulations of synthetic pyrethroids (e.g. permethrin and bifenthrin),
organophosphates (chlorpyrifos), the chloronicotinyls (imidacloprid), arsenic trioxide (as a dust for
spot treatments), and recently a phenyl pyrazole (fipronil), along with wood preservatives.

 

Termite inspection and Treatment cost

In considering which methods to use in the inspection and eradication of this pest, one of the most important question homeowners have is how much does it cost to get rid of termites. It can be quite an expensive process, depending on the amount of damage that’s already been done, as termites are known to multiply quite quickly, since they don’t requite a lot of space to live in. There are several different costs to consider when deciding between the various termite treatment options. But, considering the price of the properties in Australia, a good quality treatment it will be always cheaper than a new house.

 

The Future For Australian Cities

The problems associated with termites in Australian cities are clearly identified and requiring
innovative approaches. The identified large costs to buildings and other wooden structures from
termite damage reveals that termites remain part of the urban environment of Australian cities
following construction. The utilisation of less-persistent termiticides following the phase-out of
organochlorines has created a less desirable situation of needing to reapply chemicals every few
years to maintain barrier protection giving rise to environmental and public health consequences.
The future lies with well developed termite management strategies that incorporate the kind of
research that will lead to alternative barriers giving protection of wooden structures against termite
attack.