Conducive environmental conditions An integrated approach to bedbug management

Public Health Significance of Urban Pests 141 much more common in poorer communities, these practices probably help to rapidly and repeatedly spread bedbugs to new sites and to redistribute them to places from which they may have been eliminated earlier. Large multi-unit buildings common to poor areas can be very hard to rid of bedbugs. Once bedbugs become established, any control effort that does not include checking the whole building at nearly the same time, along with a coordinated occupant education and treatment effort as needed, will usually fail, because the bugs will frequently move away from any partially treated and potentially repellent active sites into adjacent rooms. Their movements are generally unencumbered, because they readily move through wall voids and along utility lines, heating ducts, elevator shafts, and laundry and mail chutes.

4.5. An integrated approach to bedbug management

With current pest management practices, bedbugs can only be effectively managed by combining as many different strategies, techniques and products as possible for any par- ticular set of local conditions or infestations. This makes the bedbug an ideal candidate for IPM practices, which include: • inspection • identification • establishment of threshold levels – generally, no bedbugs are acceptable • incorporation of two or more control measures • monitoring the effectiveness of controls. Particular steps may differ for given pests or unique local conditions and may take into account the need to quickly reduce a given life stage of pests that pose an impending serious health risk.

4.5.1. Conducive environmental conditions

Conditions under which the common bedbug thrives include: • an adequate supply of food available blood-meal hosts • plenty of small cracks or narrow harbourage spaces within about 1.5m of a host • ambient temperatures within a few degrees of 28–32°C • average relative humidity of 75-80. Currently occupied, cluttered bedrooms with little air movement are ideal. Sanitation alone will not eliminate a population of bedbugs; however, eliminating clutter, removing all accumulated dirt and debris and sealing cracks and crevices will reduce available har- bourages, will make it easier to detect remaining live bedbug populations and will increase the probability that any further treatment may succeed. Bedbugs 140 baseboards in only one bedroom of a separate home, would be about US 300 in most areas of Canada, most western European nations and the United States. This is based on the following: three hours of detailed inspection time, concise customer education and a very limited insecticide application by a well-trained PMP on a single visit to the site. Costs, however, will vary. In hotels and other multi-unit structures, for example, infes- tations are almost never that limited and usually require significantly more inspection, control time and effort. Because infestations may go unnoticed in these facilities, there is a much greater chance of so-called callbacks – that is, return services. Because the general public lacks knowledge of bedbug feeding activity, victims nearly always seek medical attention, usually incurring additional costs for diagnosis, or at least costs for symptomatic medical treatments. At least 17 of 65 homeless shelters in Toronto, Canada, spent an average of Can 3085 each to address bedbug problems in 2004 Hwang et al., 2005. Litigation costs can be more variable and even less well documented. Examples of judg- ments range from one award of US 382000 down to awards in the range of US 20000 plus expenses Doggett, Geary Russell, 2004; Gooch, 2005; Johnson, 2005. In early 2006, a lawsuit was filed against a hotel, seeking US 20 million in damages. It is impossible to estimate the cost of any related subsequent actions or the anxieties of bitten individuals.

4.4. Poverty, housing and bedbug infestations