Researchers working with the Western drywood termite may have found a promising new tool for controlling infestations – chitin synthesis inhibitors.
Researchers at the University of California, Riverside may have identified a significant new approach for drywood termite management. The latest recent studies demonstrate that chitin synthesis inhibitors could deliver high colony mortality while avoiding many of the drawbacks associated with traditional fumigation programs.
The research, published in the Journal of Economic Entomology, focused on the use of bistrifluron, an insect growth regulator that interferes with the termite moulting process by preventing the formation of a new exoskeleton. Laboratory trials against the western drywood termite (Incisitermes minor) achieved mortality rates approaching 95-99%, with researchers suggesting the chemistry could provide a safer and more targeted alternative to structural fumigation.
Drywood termites remain one of the pest management industry’s most challenging structural pests due to their concealed workings inside timber. Colonies can remain active for years before damage becomes obvious, while the insects’ cryptic behaviour makes accurate treatment targeting difficult.
According to the research team, the new approach exploits a biological weakness termites cannot avoid: moulting. Like all insects, termites rely on a chitin-based exoskeleton for protection and structural support. As they grow, they must periodically shed the old exoskeleton and produce a new one. Bistrifluron interrupts this process.
Rather than delivering rapid knockdown toxicity, the active ingredient gradually prevents termites from forming a viable new exoskeleton. Once exposed termites reach a moulting stage, they are unable to complete the process successfully and die.
The researchers noted that this slower mode of action may actually provide a significant advantage in colony elimination programs. Because affected termites continue interacting socially before death, the chemistry can spread throughout the colony via trophallaxis and food exchange behaviours.
Transfer studies found that even when only a small percentage of termites were directly exposed, mortality eventually reached 100% within test groups over a 90-day period. Researchers observed that treated termites transferred contaminated food material to nestmates within 24–48 hours.
The study also compared bistrifluron with other chitin synthesis inhibitors, including chlorfluazuron and noviflumuron. At the tested application rates, bistrifluron delivered faster and higher mortality outcomes.
For pest management professionals, one of the most significant aspects of the research is the potential shift toward more localised drywood termite treatments.
Traditional whole-structure fumigation remains highly effective but presents operational challenges for both technicians and homeowners. Occupants must vacate the property, food and consumables require preparation or removal, and the process can be disruptive and costly. Importantly, fumigation also offers no residual protection against future infestation once the treatment is complete.
The UCR researchers suggest chitin synthesis inhibitors may provide an alternative capable of both colony suppression and ongoing timber protection.
“Low-impact strategies like this one will become an attractive option in many cases,” senior author Professor Dong-Hwan Choe stated in the report, noting the chemistry may remain active within treated timber for extended periods.
The research team has also investigated methods to improve termite exposure to localised treatments by using behavioural attractants.
Separate UCR work examined the use of pinene, a naturally occurring compound released by pine trees, as a lure to attract termites toward treated timber. Researchers found that combining pinene with localised insecticide treatments significantly improved mortality rates compared with insecticide alone. In some studies, mortality reportedly increased from approximately 70% to more than 95%. This behavioural approach could prove particularly valuable in drywood termite management, where locating galleries and accurately targeting hidden colonies is often one of the greatest treatment barriers.
This approach of combining attractants with slow-acting transfer chemistries reflects a broader shift toward precision termite management strategies that rely less on broad-spectrum applications and more on colony biology and behaviour. The development also aligns with increasing regulatory and consumer pressure for lower-toxicity treatment options. Traditional fumigants, while highly effective, continue to face scrutiny regarding environmental impact, occupant disruption and greenhouse gas concerns.
Of course, further work is still required before bistrifluron could be used against drywood termites in real-world scenarios. Current laboratory formulations used acetone as a carrier solvent, which is highly flammable and odourous, so the research team is now investigating alternative delivery systems better suited for work in the field. While commercial adoption may still be several years away, the UCR findings suggest the next generation of termite control could focus less on blanket eradication and more on exploiting the insects’ own biology against them.
The findings are particularly relevant as drywood termite activity expands beyond traditional geographic ranges, with the western drywood termite now been detected in a wider range due to the movement of timber and wood products.
Source: ‘New Chemical Kills 95% of Termites Without Harming Humans’. University of California – Riverside. Published by ScienceDaily, May 9, 2026.
Original article: Choe, D_H et al (2025): Journal of Economic Entomology, Volume 118, Issue 3, June 2025, Pages 1373–1381, https://doi.org/10.1093/jee/toaf064
Image credit: Dong-Hwan Choe, University of California, Riverside, CA, USA
