Dr Stephen Doggett shares the results of the 2016 National Bed Bug Survey.
It has been ten years since the last comprehensive survey was undertaken of the pest management industry, in relation to the bed bug situation within Australia. Since that first national survey in 2006, numerous strategies have been implemented to combat the rise of this nuisance pest, principal amongst them the development of an industry management standard, namely A Code of Practice for the Control of Bed Bug Infestations in Australia.
Yet the question must be asked, ‘just how successful have we been in our fight against bed bugs?’ To this end, the Department of Medical Entomology at Westmead Hospital, in conjunction with the Australian Environmental Pest Management Association, undertook a national survey of pest managers through June of 2016 on matters relating to bed bugs.
The survey aimed to establish the current state of the industry in Australia, with the results being used to encourage research and education into more effective bed bug control strategies.
An online survey was created and the questions asked to get feedback on:
- The number of infestations treated per year
- Over the last year, did bed bug infestations appear to be on the increase, decrease, or were about the same
- Over the last five years, did bed bug infestations appear to be on the increase, decrease, or were about the same
- The season when most bed bug treatments were undertaken
- Property types treated
- Detection methodologies used
- The control methodologies used
- The insecticides used
- Treatment details, such as the average number of treatments, the time spent per treatment, whether a re-inspection was undertaken, treatment costs, and knowledge of the Code of Practice.
There were a total of 95 respondents to the survey. The average number of bed bug treatments per year was 27, although there was a high variation in the numbers reported, from one to many hundreds. This was because some respondents represented themselves, while others their company, with some being small local companies and others, large multi-national organisations.
When asked about how the level of bed bug infestations had changed over the last five years (Figure 1), 51.6% reported that they had increased, 16.6% decreased, and 31.6% stated that infestations remained about the same. In contrast, with infestations over the last year (Figure 2), only 40.0% indicated that bed bugs were increasing, 18.9% that they were decreasing, and 41.1% that infestations were about the same.
The majority (48.4%) of pest managers reported that summer was the peak time for bed bug treatments, although 37.9% did not notice any seasonal trend (Figure 3). As the summer months cover the peak tourist season, it is hardly surprising that this is when people bring bed bugs back home.
Regarding property type, the hospitality sector produced the overall highest percentage of treatments (51.6%) and included 1-3 star hotels (18.4), backpacker lodges (16.0%), 4-5 star hotels (13.8%) and caravan parks (3.5%). Private homes had 42.9% (detached homes, 24.2%; units, 18.6%). The transport sector had 3.5% of the infestations, and small percentages were reported from boarding houses (1.8%), schools and universities (0.4%), and hospitals (0.03%).
In terms of detection technologies, all pest managers reported undertaking visual inspections, 28.1% used passive traps (no lure present) and 15.6% used glue boards. A very small number (2.3%) employed active traps, while 7.3% used pitfall traps, and 2.4% used bed bug detection dogs.
Pest managers used a range of non-chemical control options: vacuuming (55%), steam (34%), heat (25%), and mattress encasements (56%).
For the chemical treatments, 100% of pest managers reporting using insecticides. Around half (47.8%) used fourth generation pyrethroids, 41.1% used combination products (that contain a neonicotinoid and pyrethroid), 27.8% used carbamates, 15.6% used permethrin, 14.4% chlorfenapyr, 11.1% used insect growth regulators, and there was a mix of other products. Note that these numbers do not total 100% as most reported using multiple products.
A small number of respondents (5.2%) reported using unregistered products.
Regarding the treatment processes, on average respondents undertook 2.2 treatments (visits), with 2.2 hours spent per treatment (approx. 4.5 hours in total), at an average cost of $430. Seventy three percent reported always reinspecting after each treatment, 91.3% were aware of the Bed Bug Code of Practice and 85.5% considered that the Code assisted them in their bed bug management practices.
The 2016 national bed bug survey revealed that the Australian pest management industry has come a long way since the first survey in 2006. Clearly, the biggest difference over the ten years was the change in bed bug infestations. From the 2006 survey, 93.5% of respondents reported that bed bugs were increasing, which is well above the recent survey. It would appear that bed bugs are no longer on the increase and perhaps we have hit the turning point, where overall numbers of infestations will decline.
In 2006, 68.9% of the infestations were reported from the hospitality sector (compared with 51.6% in 2016), 21.4% were in private homes (compared with 42.9% in 2016), and transport was slightly higher at 7.4% in 2006 (compared with 3.5% in 2016). Overall, it appears in 2016 that you are less likely to acquire bed bugs while travelling and bed bugs are appearing in less diverse locations.
There is now a much greater reliance on non-chemical means of control than back in 2006. Around 55% reported using vacuums and 34% used steam in the recent survey, compared with 22.5% and 21.6% in 2006 respectively. This is great news, as modern bed bugs are highly resistant to most insecticides on the market, and by employing non- chemical means such as a cheap vacuum cleaner, the overall biomass of the infestation can be dramatically reduced, requiring less efforts for the chemicals to mop up the stragglers. There have been several studies that have demonstrated that an integrated approach to bed bug control results in a greater probability of success.
A number of pest managers (43.8%) are now using passive traps, whereas no one reported employing these back in 2006. However, most traps have not undergone independent testing to verify their efficacy, and at present there appears to be little scientific justification for their use over other means of detection such as visual inspection. Of those using traps, 36% stated that they used glue traps. Bed bugs tend to be repelled by sticky surfaces and so glue traps will always underestimate the actual incidence of bed bugs, and thus should be avoided.
As to the insecticides, it is promising that many are now using the combination products containing a pyrethroid and a neonicotinoid, which were not on the market back in 2006. It is however important to note that resistance to both of these groups have been reported and so treatments success should always be determined.
A number of respondents reported only using pyrethroids, including permethrin, one of the older pyrethroids. Such products are best avoided, except in an aerosol formulation, due to the issues with resistance. Several respondents mentioned they use insect growth regulators (IGRs) for bed bug control. This is a very controversial group of insecticides when it comes to bed bugs, as the chemical will not kill the insect directly. For the chemical to work, the insect has to have a blood meal, which means that you are relying on your customer to suffer in order to achieve control. This naturally raises ethical issues, and also potential legal liabilities if your client became aware of what you are doing to them.
In the 2006 survey, many pest managers reported using unregistered insecticides and there were fewer (yet some) in the 2016 survey. Always check that bed bugs are on the label, otherwise you are breaking the law.
Bed bug management is always challenging, not only due to the poor performance of insecticidal products due to resistance, but the insect can hide in narrow cracks and crevices making detection very difficult. Furthermore, most insecticides will not kill the eggs and a period must be allowed for egg hatching between treatments. For these reasons the Code of Practice, even from the draft first edition in 2006, recommends that a follow up inspection must always be undertaken with every treatment. Thus it is disappointing that 16.7% of respondents still only undertake one treatment and most of these failed to undertake a re-inspection.
The costs charged by pest managers also varied tremendously from $100 per treatment to $2,000 for eradication. It is interesting that most of those charging very low amounts only took one treatment and failed to reinspect. I suspect that many are probably failing in their treatment and simply not knowing it.
Finally, it is comforting that so many have heard of the ‘Bed Bug Code of Practice’ and have found it useful in their practice. The Code is up to its fourth edition and is due for an update in 2017. Keep reading Professional Pest Manager for news of its release and check the Code website.
Stephen Doggett, Department of Medical Entomology, Westmead Hospital, Sydney