Some great examples of arboreal termite nests and some things to be aware of regarding water tanks.

Let’s go arboreal

Locating termite nests can be very challenging for most species, but for Nasutitermes it’s generally a lot easier. Nasutitermes exitiosus build visible mounds on the ground (typically in eucalyptus areas) and Nasutitermes walkeri (also known as the ‘tree’ termite) build arboreal nests. They typically build their nests on the main trunk of trees or in a major fork. As they are subterranean termites, they still need a connection to the soil.

Warwick Madden from Further Research and Consulting spotted a classic Nasutitermes walkeri nest (Figure 1) on Barrenjoey Head in Sydney. Can you spot the three other nests in the background?

Figure 1: Several Nasutitermes nests on Barrenjoey Head, Sydney
Figure 1: Several Nasutitermes nests on Barrenjoey Head, Sydney

Paul Mantel from All Pest Solutions in northern NSW found it pretty easy to spot the colony responsible for the damage present in a nearby shed (Figure 2). With such an obvious nest, physical removal/destruction was part of the termite management process.

A large Nasustitermes nest
Figure 2: A Large Nasutitermes nest in northern NSW – physical destruction and removal

Beware of water tanks

 Water storage tanks (drinking water and rainwater) come in all shapes, sizes and locations. Water tanks are commonly in the roof, hot water tanks in the house and around the building perimeter, and rainwater tanks can be found around the perimeter underneath buildings. All are potential termite hotspots. Not only do they often obstruct inspection, but they are obviously a great moisture source for termites.

Bruce Dekker from ProTrain detected an unusual entry point at a Sunshine Coast property – an underfloor concrete water tank (Figure 3). The residence was an infill type construction and Mr Dekker believed the termites (Coptotermes frenchii) probably started downward from formwork when the water level was lower. Rains had increased the water level flooding the termite lead – you can see termites floating on the water (Figure 4).

Figure 3: Inspection hatch of underfloor water tank
Figure 3: Inspection hatch of underfloor water tank
Figure 4: Termite lead flooded by rising water
Figure 4: Termite lead flooded by rising water

Tim Kingston from First Choice Pest Control in Toowoomba came across a somewhat unconventional soil perimeter treatment, where drill and inject had continued around a hot water heater on the perimeter wall (Figure 5). Alas this is not the first time such a treatment has been witnessed and there was good discussion amongst pest managers on the Australian Pest Managers Network Facebook page.

Drill and insect around a hot water tank?
Figure 5: Drill and inject around a hot water tank?

Clearly this is not a treatment that meets labels and standards. But if the correct treatment was offered to the client (removal of hot water tank to carry out the treatment then replace), but subsequently declined – and this was carried out as a ‘better than nothing’ alternative, and both the original recommendation and the limitation recorded on the treatment advice – then from a legal point of view the pest manager would have been covered.

Gary Byrne, technical manager at Rapid Solutions, emphasised this point. “Ensuring complete documentation and explaining the limitations to the customer and recording the limitations is a key factor in helping to provide protection from a future claim. Clearly, this is a common situation and the removal of any water tank or obstruction to carry out a compliant treatment is the best option and should be the first recommendation in writing.

“For a chemical treatment, the termiticide needs to be continuous against and around the slab or foundation to comply with AS 3660. Baiting systems could also be installed around the tank as an extra risk reduction measure where the client will not accept your recommendation to have it removed for treatment, although any tank obstructing the perimeter will prevent clear inspection of the building perimeter and therefore will also require some definite limitation statement.”

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