(See also Termite Treatment Without Chemicals, About Termites and Termite-resistant Tree Species below)
The Neem tree (Azadirachta indica), is indigenous to South-East Asia, where it is grown in plantations. Plantation establishment and individual plantings have occurred in sub-Saharan Africa, the Middle East, dryland Central Africa, India, Indonesia, Mexico and Nicaragua. Over the past 50 years it has spread throughout tropical Australia without apparently being considered a problem. Neem plantations have already been established in northern Queensland, and more will follow.
Oil from the neem seed has been famous in India for centuries, where it is used as a pesticide and fungicide, and also for birth control and cosmetics. In Australia, it is gaining a reputation in agriculture as an insect deterrent (eg, for grasshoppers) and domestically for its effective prevention and control of headlice and fleas 1. Tests by researchers in Qld and NSW as well as by the CSIRO in Melbourne have shown that neem extract at the strength of 0.5% azidarachtin, and with pyrethrum oil added, efficiently got rid of multi-species termite infestations in old stumps, roots and timber poles, etc.
Neem is one of the world's first rainforest trees to be fully understood biochemically, and is attracting undue attention from large corporations, eager to establish bio-patents of its properties. Fortunately, the first international legal case in the U.S. was thrown out of court.
More recently, Australian companies have been doing their own research: one trial has shown its ability to help produce superior, bug-free cotton crops; another researcher has produced a line of cosmetics based on a combination of neem and hemp seed oil; Queensland research has created formulations of neem seed extracts suitable for agricultural and medicinal applications.
Like neem, pyrethrum is a natural, plant-derived insect deterrent. Many proprietary brands of fly spray, cockroach repellent, etc, use a synthetic form of pyrethrum called Pyrethrin. However, it is still possible to obtain the pure plant extract 2.
(to be updated)
Precautions such as those needed when working with chemically treated timber 3, show some of the dangers and limitations inherent in chemically-based approaches to timber use. Some thought as to how to best use timber might lead us to alternative solutions 4.
It is now possible to design-out the need to chemically treat for termites, for example, by simply making all new homes inaccessible to them. Termites are an important part of the forest ecosystem in that they assimilate dead timber and convert it into useful plant and tree food.
Until recently, the 'normal' course of action to eradicate termites was to place arsenic trioxide powder in their tunnels, or spray their nest with 'horror-show', organochlorine chemicals like Chlordane or Dieldrin in order to obliterate every single living being inside. Any animal, human or otherwise, within the the same catchment/ecosystem was likewise at risk for many years. Chlordane, Dieldrin, Heptachlor, etc, are 'persistent' - they remain an active hazard in the environment for many years. Despite the heavy-handedness of the above methods, none of the substances is fully efficient or a long-term deterrent.
Newer, earth-friendly options include spray applications of neem-pyrethrum extracts, (see above) laying of mesh or granite barriers during construction 5. These are not only safer for people, they allow the termites to retain their (rightful) place in the environment, be it urban or rural.
Similarly, please consider alternative building-materials that are unpalatable to fungus and borers as well as termites, and which may be better suited to the climate and weather 6.
Termites fall into three categories:
It is the subterranean species of termite which are the most voracious devourers of woodwork in Australian buildings. Of these, the species Copta Termes does more than 90 percent of the damage. Subterranean termites can live many hundreds of metres from a targeted dwelling. Distance is almost irrelevant to them, as long as they have raw material with which to build their tunnels (or 'galleries') and moisture for sustenance. They can then progressively mount their 'attack' by tunnelling many metres underground if need be. Softwoods are their most cherished food source, but they will eat many harder species which lie in their path.
This Guide recommends constant vigilance and effective barriers as keys to successful termite control. The Australian Environmental Pest Managers Association says there are four factors: Inspection and monitoring, environmental controls, eradication, and protection. Apart from the AEPMA, the CSIRO is one of the foremost authorities on termite species identification and their nesting, tunnelling and feeding habits.
(Listing compiled by Systems Pest Management7)
NB: Choose only those species marked as being plantation-grown ie, with a (P) or (OS) after the botanical name.
Do not use those species marked with an (X) unless a salvaged, recycled, local plantation or overseas plantation source can be found and verified.
Blackbutt (Eucalyptus pilularis) (P) (OS)
Blackdown Stringybark (E. sphaerocarpa) (X)
Bloodwood (E. corymbosa) (X)
Broad-leaved Red Ironbark (E. fibrosa) (X)
Brown Mallett (E. astringens) (P)
Coast Grey Box (E. bosistoana) (X)
Forest Red Gum (E. blakeleyi / E. tereticornis) (X)
Grey Box (E. moluccana) (X)
Grey Gum (E. canaliculata) (X)
Grey Ironbark (E. paniculata) (X)
Gympie Messmate (E. cloeziana) (P)
Jarrah (E. marginata) (P but limited mainly to sources in W.A.! Exercise caution! Consider it to be mostly (X) rated.)
Long-leaved Box (E. goniocalyx) (X)
Narrow-leaved Red Ironbark (E. crebra) (X)
New England Blackbutt (E. andrewsii) (X)
Red Bloodwood (E. gummifera) (X)
Red Box (E. polyanthemos) (X)
Red Ironbark (E. sideroxylon) (X)
Red Mahogany (E. resinifera) (X)
Red Stringybark (E. macrorhyncha) (X)
River Red Gum (E. camaldulensis) (P) (OS)
Salmon Gum (E. salmonophloia) (X)
Scribbly Gum (E. Haemastoma) (X)
Southern Mahogany (E. botryoides) (X)
Spotted Gum (E. maculata) (P)
Sugar Gum (E. cladocalyx) (X)
Tallowwood (E. microcorys) (P)
Tuart (E. gomphocephala) (X)
W.A. Blackbutt (E. patens) (X)
Wandoo (E. wandoo) (X)
White Mahogany (E. acmenoides) (X)
White Stringybark (E. eugenoiides) (X)
Woolybutt (E. Longifolia) (X)
Yellow Box (E. melliodora) (X)
Yellow Gum (E. leucoxylon) (X)
Yellow Stringybark (E. muelleriana) (OS)
Yertchuk (E. consideniana) (X)
Black Bean [heartwood] (Castanospermum australe) (OS)
Brigalow (Acacia harpophylla) (X)
Brushbox (Lophostemon confertus) (OS)
Brown Penda (Xanthostemen chrysanthus) (X)
Bulloak (Allocasuarina luehmannii) (X)
Raspberry Jam (Acacia acuminata) (X)
Red Penda (Xanthostemen whitei) (X)
Satinay (Syncarpia hillii) (OS)
Swamp Box (Lophostemon suaveolens) (X)
Turpentine (Syncarpia glomulifera) (OS)
Black Cypress Pine (Callitris endlicheri) (X)
Celery Top Pine (Phyllocladus asplenifolius) (X)
Huon Pine (Lagarostrobus franklinii) (OS)
King William Pine (Athrotaxis selaginoides) (X)
White Cypress (Callitris columellaris) (OS)
Burmese Teak (Tectona grandis) (OS)
Kwila [/Merbau] (Intsia bijuga) (C)
New Guinea Rosewood (Pterocarpus indicus) (C)
Redwood (Sequoia sempervirens) (X)
Western Red Cedar (Thuja plicata) (C)
(P) Plantation grown in Australia (for more info on these, see Australian-grown Plantation Timber Species). If possible, get verification that a particular species is plantation grown: some species available from plantation sources may be rare or even endangered in the natural forest context.
(OS) Overseas grown in plantations (for more info on these, see Overseas-grown Australian Timber Species). Unless also marked with a (P), do not buy from an Australian source!
(C) Limited certified sources available. Get proof of certification by the FSC, otherwise avoid using.
(X) Avoid, whether local or imported; unless a salvaged, recycled, local plantation or overseas plantation source can be found and verified. (Please let the Guide know if you find any plantation sources! of these species!)
1. See under Non Toxic Pest Management
2. See under Non Toxic Pest Management
3. See Take Care if You use Treated Timber.
4. See the article Durable Native Softwoods - the Ethical Solution to Toxic Timber Treatments.
5. See the book, Building Out Termites; or contact Granitgard, TermiMesh, or Systems Pest Management directly. Also, check back issues 67, 74, 83 of Earth Garden Magazine.
6. See Non Timber Building Materials.
7. See also Building Out Termites