Reducing domestic damage from the world's most destructive drywood termite
The forest and wood products industry, through the FWPA-supported Centre for Timber Durability and Design Life, has teamed up with the Queensland government and academics to undertake a research project that will discover more about the West Indian drywood termite (WIDT) — also known as Cryptotermes brevis.
The goal is to improve decision-making around WIDT pest mitigation strategies. The outcomes of this research will help to develop more effective methods of detection, management and elimination, for what is widely considered the world's most destructive drywood termite.
Originating from Chile, WIDT now has an almost worldwide distribution, and is thought to have been introduced into Australia as far back as the 1940s.
Domestically, it is most commonly found in South East Queensland and has caused considerable economic harm due to its damaging impact on timber structures across locations including Brisbane, Maryborough, Bundaberg, Rockhampton and Townsville.
Furthermore, WIDT can easily be transported to other locations through the movement of infested timber. Once an infestation has been established, the termites winged reproductive ‘castes’ or ‘alates’ have the ability to fly short distances and find new timber structures to infest, causing further damage.
In Australia, WIDT has most commonly been observed in hoop pine, as well as cabinet woods such as maples (Flindersia species), red cedar (Toona australis) and silky oak (Grevillea robusta). However, the overall host range of timber species is still unknown. Determining which species are at risk has therefore formed an important part of this investigation.
Dr Babar Hassan joined the FWPA-supported Centre for Timber Durability and Design Life in 2020 as a Research Fellow, bringing with him extensive experience in termite biology. Since assuming this position, Dr Hassan has been actively engaged with several projects, including working with Consulting Entomologist Dr Don Ewart, and Melbourne-based pest control company Pest Register, to update termite risk maps in light of reports that some termite species are moving south. He has also been involved in developing a major review of termite testing methods.
Dr Hassan has been collaborating with Janet McDonald, Chris Fitzgerald, and Jock Kennedy of the Department of Agriculture and Fisheries, Queensland (DAF), and Dr Andrew Hayes of the University of the Sunshine Coast to collect vital information on WIDT.
“The current DAF prevention and control program has been focused on detection of infestations in structures via the removal of elements such as wall coverings, or investigation of termite frass (i.e. faecal pellets) piled beneath or in the damaged wood, to confirm the presence of WIDT in the timber underneath,” said Hassan.
“Once detected, the only effective treatment known to limit the spread is a whole-of-building fumigation using a toxic gas known as sulfuryl fluoride.
“This approach to detection and control is costly and laborious, and does not prevent re-infestation,” said Hassan.
The research team has therefore been investigating non-destructive detection methods for WIDT, and researching feeding preferences, responses to heat exposure, and various other biological aspects relevant to the development of better prevention and control methods.
The first step in this process saw Dr Hassan develop a plan to house colonies at the EcoSciences Precinct at Dutton Park. By laboriously collecting several thousand termites from an infested building and introducing them to the facility, the team has been able to test a radar-based tool known as Termatrac™ for its effectiveness in the detection of WIDT without the need to dismantle any elements of the structure.
The team has also evaluated the efficacy of exposure to different temperatures as a method of killing the termites. The researchers tested temperatures of between 45 and 55 degrees Celsius, in order to ensure the pest can be targeted without damaging the timber itself.
The project recently received approval from Biosecurity Queensland to maintain colonies in quarantine-safe cages, where the WIDT infested timber is housed and can be studied further.
“The results will provide information for effectively detecting termites in situ, before using heat for elimination,” said Hassan.
These elements of the project are nearing completion, with the results set to be published in the near future.
An additional element of the study will focus on determining whether it is possible to ascertain the age of infestation by studying the associated termite frass found in the timber. This would help determine the most effective approach to control and elimination for each specific instance of WIDT infestation.
A PhD student from the UK is due to arrive in Australia later this year to progress this additional element of the research.