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control techniques to use against them. Several different active ingredients and formu- lations have been licensed and are currently used against bedbugs, and a variety of insec-
ticide formulations and devices must be used to treat infested harbourages. As per label directions, applications of dust formulations should be used in electrical outlet boxes and
in other places where it is desirable to use a minimum-risk, long-lasting insecticide.
4.5.5.5. Use of pest management products
The use of a properly labelled or licensed insecticide formulation in combination with the IPM principle recommended for control of bedbugs will often be the quickest, most prac-
tical and in some cases possibly the only affordable or viable control option. Most resi- dual insecticides that are labelled or licensed or recommended for the control of bed-
bugs are only intended for use as a crack-and-crevice treatment, according to directions on their product labels. The vast majority of such currently available products are either
natural or synthetic pyrethroids; some of these products include synergistic chemicals as well.
Recommendations in Canada, Europe and the United States for the control of bedbugs cover pyrethrins such as 6 mlm
2
synergized natural pyrethrum, pyrethroids such as permethrin, organophosphates such as 50 mlm
2
fenthion, 4–8 vv and carbamates such as 200 mlm
2
propoxur, 1 wv. For any class of insecticide product active ingre- dient included in products currently labelled for use to control bedbugs, type I pyrethroids
are among the least toxic. The application concentration of pyrethroid active ingredients registered as bedbug control products is seldom more than 1 vv. Also, most non-resi-
dual pyrethroids are rapidly detoxified by normal exposure to sunlight, oxygen in air, common household cleaning agents and microbes routinely found on nearly all exposed
surfaces. For monitoring and for improving control results, certain aerosol formulations of pyrethroids are sometimes used to stimulate flush hidden bugs, so they will move out
of cryptic harbourages, making their presence more readily detectable; however, such aerosol products seldom kill many of the bedbugs that emerge.
Dust formulations of insecticidal products currently labelled for use in controlling bed- bugs are of low toxicity and pose little risk to people when used in accordance with label
directions.
IGRs are used to alter bedbug reproductive processes. Such regulators have essentially no effect on vertebrate systems as applied, because of their modes of action and because
of the very small amount of active ingredient applied when used according to label direc- tions. They can, however, have a significant impact on bedbug fertility and the success of
egg hatching Takahashi Ohtaki, 1975.
Currently, the vast majority of pesticide products labelled for use on mattresses contain very low concentrations of very low-toxicity and low-volatility pyrethroid formulations
or else their active ingredients are such non-insecticide products as silica aerogel or dia- tomaceous earth.
Any such licensed pest management products for use on mattresses, as well as nearly all
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Products listed in this section are for illustrative purposes only. The choice of insecticide products and specific application techniques can depend on many factors, which include
the following:
• the physical locations and structural details of the bugs’ harbourages • the availability of the product
• the products’ own labels, which can vary greatly from country to country • exact local conditions
• any applicable national and local laws or regulations • many different, related official recommendations.
True fumigation of small volumes or limited amounts of furniture, clothing, or other personal items can kill all stages of bedbugs present, possibly including bedbug eggs. Such
a treatment, however, would not prevent reinfestation immediately after the fumigant had been sufficiently removed for the items treated to be used again. True fumigation of
a whole building should be equally effective at killing all mobile stages of bedbugs pre- sent, but would not prevent a reinfestation and would seldom be needed, practical or
affordable WHO, 1982; Snetsinger, 1997; Gooch, 2005.
4.5.5.1. Surface treatments
Limited, precisely placed treatments of selected surfaces, using properly formulated resi- dual insecticides, can provide at least a temporary lethal or perhaps repellent barrier
and thus can help reduce biting of nearby hosts.
4.5.5.2. Impregnated fabric and bednets
Fabrics and bednets that are factory- or self-impregnated with licensed and commer- cially available formulations of residual insecticides can help deny bedbugs access to hosts
and may even kill some of the bugs that crawl across them. This can be economical, since some spray, dipping or coating formulations of products containing permethrin will
remain on clothing at their full applied strength through six or more launderings, or even for the life of the fabric Lindsay et al., 1989; Faulde, Uedelhoven Robbins, 2003. This
treatment is done during the manufacture of the fabric and not by a pest control company when the fabric is in place. There is a recent report of pyrethroid resistance to the use of
treated bednets in a population of tropical bedbugs Myamba et al., 2002.
4.5.5.3. Ultra-low-volume aerosols or foggers
Insecticide products currently labelled as ultra-low-volume ULV aerosols or foggers have little or no residual effects and act as a flushing agent. Most of them can stimulate
bedbugs hidden in harbourages to become active and move out into the open, allowing them to be noticed more easily. Some of those bugs may be killed by prolonged or repea-
ted exposures, but control would be successful for only a small percentage of the bugs flushed from harbourages.
4.5.5.4. Crack-and-crevice treatments
Because bedbugs habitually hide clustered together in cracks and narrow harbourages, precisely applied crack-and-crevice treatments may often be among the most effective
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• For populations of all three bedbug species that routinely feed on people, research should be encouraged and carried out to determine the susceptibility of bugs collected
in field studies to the insecticides most frequently used at present to control them. • Research should be encouraged and carried out to determine whether or not bedbugs
can successfully transmit human pathogens, especially those that cause new or emer- ging diseases.
• Research should be encouraged and carried out to further characterize the nature and effective treatment of the effects on people of unusual, extreme or very persistent bed-
bug bites. • Research should be encouraged and carried out to clarify more specific aspects of the
physiology and behaviour of bedbugs, with a secondary goal of developing effective techniques or devices that can efficiently and quickly survey for the presence of even
small populations of bedbugs.
• Research should be encouraged and carried out to determine the effectiveness and prac- tical use of extreme temperatures especially heat to eliminate or control bedbugs in
human habitats. • Efforts should be undertaken or at least planned by appropriate government agencies
to address locally evident problems that relate to the difficulties encountered by poor and low-income people in dealing with bedbugs and their control and with housing or
building quality. Community-wide or citywide programmes may be needed and pos- sible, if properly supported and well coordinated.
• Research should be encouraged and carried out to discover and make available new insecticide active ingredients, products, and devices and techniques that will be effec-
tive in controlling bedbugs.
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of the pyrethroids labelled for control of bedbugs at any indoor site, pose no significant risk to human health, if they are used in accordance with their individual product label
directions Cooper Harlan, 2004; WHO, 2005.
4.6. Benchmarks for success in bedbug management
Some benchmarks that may help in evaluating the success of a bedbug control effort include:
• the lack of live bedbugs, cast skins after those present earlier have been removed, fae- cal spots on bed linens or harbourage sites, and unhatched eggs;
• the lack of new feeding activity, as evidenced by occupants of previously infested sites having no new bites such as no evidence of bites at new sites appear more than 10 days
after the most recent control effort; • no new complaints of bites with symptoms resembling typical bedbug bites from occu-
pants of rooms or apartments dwelling units adjacent to or near, but not included among, the most recently treated similar sites;
• new knowledge received and retained by residents, from local direct inquiry or from a survey that shows that occupants of recently treated sites and their neighbours and ser-
vicing pest management technicians have a good general knowledge of the bugs, their biology and their signs and that they have a good understanding of preventive tech-
niques and effective control strategies against bedbugs;
• careful and thorough follow-up surveillance at five weeks or longer after the most recent treatment still shows no signs of a presence of live bedbugs; and
• an absence of recent bedbug infestations or bites being reported to public health or other government agencies.
Note: The absence of new bites assumes that the victims were not suffering from delu-
sory parasitosis. Continued so-called bites in the absence of bugs and after careful inspec- tion may imply delusory parasitosis, a condition that can be only addressed by medical
professionals.
4.7. Conclusions
To improve prevention and control of bedbug infestation, the following is suggested. • Steps should be taken to make accurate and practical current information readily and
widely available to PMPs, health professionals and the general public. This should include information about the biology and behaviour of bedbugs and about effective
control and prevention strategies against them.
