Bed Bug Populations Research Articles

Differential Gene Expression Profiling in Bed Bug (Cimex Lectularius L.) Fed on Ibuprofen and Caffeine in Reconstituted Human Blood

The recent resurgence of the common bed bug (Cimex lectularius L.) infestations worldwide has created a need for renewed research on biology, behavior, population genetics and management practices. Humans serve as exclusive hosts to bed bugs in urban environments. Since a majority of humans consume Ibuprofen (as pain medication) and caffeine (in coffee and other soft drinks) so bug bugs subsequently acquire Ibuprofen and caffeine through blood feeding. However, the effect of these chemicals at genetic level in bed bug is unknown. Therefore, this research was conducted to determine differential gene expression in bed bugs using RNA-Seq analysis at dosages of 200 ppm Ibuprofen and 40 ppm caffeine incorporated into reconstituted human blood and compared against the control. Total RNA was extracted from a single bed bug per replication per treatment and sequenced. Read counts obtained were analyzed using Bioconductor software programs to identify differentially expressed genes, which were then searched against the non-redundant (nr) protein database of National Center for Biotechnology Information (NCBI). Data on comparison of differentially expressed genes between control and Ibuprofen treatments revealed that 659 genes were significantly differentially regulated and 95% of them returned BLAST hits. Heat stress proteins were among the top significantly differentially down regulated genes. Comparison of the control vs caffeine treatments revealed that 2,161 genes were significantly differently regulated (Padj <0.05). Heat shock proteins were among the top ten down regulated genes in both treatments. Finally, using RNAi to identify the exact function of these highly differentially expressed genes and regulating these genes may offer potential for managing bed bug populations.

Outbreeding effects in an inbreeding insect, Cimex lectularius

In some species, populations with few founding individuals can be resilient to extreme inbreeding. Inbreeding seems to be the norm in the common bed bug, Cimex lectularius, a flightless insect that, nevertheless, can reach large deme sizes and persist successfully. However, bed bugs can also be dispersed passively by humans, exposing inbred populations to gene flow from genetically distant populations. The introduction of genetic variation through this outbreeding could lead to increased fitness (heterosis) or be costly by causing a loss of local adaptation or exposing genetic incompatibility between populations (outbreeding depression). Here, we addressed how inbreeding within demes and outbreeding between distant populations impact fitness over two generations in this re-emerging public health pest. We compared fitness traits of families that were inbred (mimicking reproduction following a founder event) or outbred (mimicking reproduction following a gene flow event). We found that outbreeding led to increased starvation resistance compared to inbred families, but this benefit was lost after two generations of outbreeding. No other fitness benefits of outbreeding were observed in either generation, including no differences in fecundity between the two treatments. Resilience to inbreeding is likely to result from the history of small founder events in the bed bug. Outbreeding benefits may only be detectable under stress and when heterozygosity is maximized without disruption of coadaptation. We discuss the consequences of these results both in terms of inbreeding and outbreeding in populations with genetic and spatial structuring, as well as for the recent resurgence of bed bug populations.

Bed bugs (Cimex lectularius): Biology and their Role as Pests to Humans

Bed bugs (Cimex lectularius) are blood feeding ectoparasites that have evolved as human pests due to their unique biology and reproduction. Common side effects of bed bug bites include: skin lesions, localized inflammation, itchiness and anxiety. There are numerous control methods to reduce bed bug populations such as vacuuming, steaming, laundering, exposure to extreme temperatures and chemical eradication methods. Bed bugs have become resistant to pyrethroid insecticides and DDT, supporting the cosmopolitan reemergence of bed bugs in the last couple decades.

Simple, rapid and cost-effective technique for the detection of pyrethroid resistance in bed bugs,Cimexspp. (Hemiptera: Cimicidae)

A ready to use d-allethrin impregnated mat (‘Mortein Odourless Mozzie Zapper’, Reckitt Benckiser) was used to detect pyrethroid resistance in bed bugs, Cimex spp. Bed bugs of different species, stages and strains were confined on the mat and knockdown measured over 24 h. The insecticide-susceptible ‘Monheim’ strain of Cimex lectularius was significantly (P < 0.001) more sensitive than the insecticide-resistant ‘Sydney’ strain of C. lectularius and the ‘North Queensland’ strain of C. hemipterus. Based on the results, a protocol to rapidly diagnose pyrethroid resistance is suggested whereby, unless 100% of 10 bed bugs (irrespective of the life stage) are knocked down after 1 h exposure to the d-allethrin impregnated mat at room temperature of 23 ± 1°C, the population can be considered resistant. This protocol was validated using six Australian field-collected strains of C. lectularius, which were known to possess ‘kdr’-type resistance mechanisms, of which there was no mortality at 1 h exposure. Thus, the protocol developed in this study can be used to monitor pyrethroid resistance in bed bug populations and should assist pest managers in determining the most appropriate control strategies for managing bed bug infestations.

Effect of feeding status on mortality response of adult bed bugs (Hemiptera: Cimicidae) to some insecticide products.

Fresh and aged residual deposits of several insecticide products were tested against bed bug adults to determine if a recent bloodmeal affected their mortality response to the residues. The bed bugs with a recent bloodmeal survived significantly longer compared with the unfed ones on their exposure to fresh or aged residual deposits of chlorfenapyr and aged residual deposits of deltamethrin on a wooden substrate. Even though the survival time of fed bed bugs was significantly longer than that of unfed ones on their exposure to fresh residue of deltamethrin and aged residue of desiccant pyrethrin dust, these treatments resulted in similarly high final mortalities regardless of feeding status of the insects. Mortality responses of fed and unfed bed bugs were similar to fresh or aged residual deposits of imidacloprid + cyfluthrin combination and fresh residual deposits of desiccant pyrethrin dust. Topical application assays indicated that a recent bloodmeal significantly increased the bed bug's survival time for chlorfenapyr, but not for deltamethrin. Pyrethroid-resistant bed bugs also showed a similar increase in their survival time for chlorfenapyr after a bloodmeal. The comparison of mortality responses between fed and unfed bed bugs treated with similar amount of chlorfenapyr per fresh body weight indicated that increased body mass was not the primary cause for this bloodmeal-induced tolerance increase for chlorfenapyr. Because the surviving bed bugs can continue ovipositing, the effectiveness of chlorfenapyr residual deposits in bed bug harborages could be significantly affected by the feeding status of the adult bed bug populations.

Questing activity in bed bug populations: male and female responses to host signals.

A large-arena bioassay is used to examine sex differences in spatiotemporal patterns of bed bug Cimex lectularius L. behavioural responses to either a human host or CO2 gas. After release in the centre of the arena, 90% of newly-fed bed bugs move to hiding places in the corners within 24 h. They require 3 days to settle down completely in the arena, with generally low activity levels and the absence of responses to human stimuli for 5 days. After 8–9 days, persistent responses can be recorded. Sex differences are observed, in which females are more active during establishment, respond faster after feeding, expose themselves more than males during the daytime, and respond more strongly to the host signal. The number of bed bugs that rest in harbourages is found to vary significantly according to light setting and sex. Both sexes stay inside harbourages more in daylight compared with night, and males hide more than females during the daytime but not during the night. The spatial distribution of the bed bugs is also found to change with the presence of CO2, and peak aggregation around the odour source is observed after 24 min. Both male and female bed bugs move from hiding places or the border of the arena toward the centre where CO2 is released. Peak responses are always highest during the night. Bed bug behaviour and behaviour-regulating features are discussed in the context of control methods.

Population variation in and selection for resistance to pyrethroid-neonicotinoid insecticides in the bed bug

Pyrethroid resistance in bed bugs, Cimex lectularius, has prompted a change to combination products that include a pyrethroid and a neonicotinoid. Ten populations of bed bugs were challenged with two combination products (Temprid SC and Transport GHP). Susceptibility of these populations varied, with the correlated response of the two products indicating cross resistance. We imposed selection on three populations using label rate Temprid, and then reared progeny from unselected and selected strains. All selected strains were significantly less susceptible to Temprid SC than unselected strains. Temprid selected strains were also less susceptible to Transport. The pyrethroid component of Temprid showed a significantly higher LD50 in selected strains, but susceptibility to the neonicotinoid remained unchanged. Taken together these results indicate resistance to combination insecticides is present in field populations at levels that should be of concern, and that short-term selection affecting existing variance in susceptibility can quickly increase resistance.

Spatial and Temporal Patterns inCimex lectularius(Hemiptera: Cimicidae) Reporting in Philadelphia, PA

We analyzed a comprehensive telephone log of pest infestation reports to assess the spatial and temporal trends in Cimex lectularius L. (bed bug) reporting throughout Philadelphia, PA. Citywide spatial analyses of reports from September 2011 to June 2012 revealed several statistically significant bed bug hotspots. However, these were small and diffuse. Temporal analyses of reports from December 2008 to May 2011 detected prominent seasonality in bed bug reporting, peaking in August and reaching a nadir in February each year. Controlling for seasonal cycling, the number of bed bug reports in Philadelphia increased steadily at a rate of approximately 4.5% per month (or 69.45% per year) from December 2008 to May 2011. While it may be difficult to spatially target citywide bed bug control measures because of the insects' widespread migration, interventions informed by seasonal trends may enhance efforts to curb the recent increases in urban bed bug populations.

Effectiveness of a Reduced-Risk Insecticide Based Bed Bug Management Program in Low-Income Housing.

Bed bug (Cimex lectularius L.) infestations are becoming increasingly common in low-income communities. Once they are introduced, elimination is very difficult. As part of the efforts to develop effective and safe bed bug management programs, we conducted a laboratory study evaluating the efficacy of a reduced-risk insecticide—Alpine aerosol (0.5% dinotefuran). We then conducted a field evaluation of a reduced-risk insecticide based integrated pest management (IPM) program in low-income family apartments with young children. In laboratory evaluations, direct spray and 5 min exposure to dry Alpine aerosol residue caused 100.0 ± 0.0 and 91.7 ± 8.3% mortality to bed bug nymphs, respectively. Direct Alpine aerosol spray killed 91.3 ± 4.3% of the eggs. The IPM program included education, steam, bagging infested linens, placing intercepting devices under furniture legs and corners of rooms, applying Alpine aerosol and Alpine dust (0.25% dinotefuran, 95% diatomaceous earth dust), and regularly scheduled monitoring and re-treatment. Nine apartments ranging from 1–1,428 (median: 29) bed bugs based on visual inspection and Climbup interceptor counts were included. Over a 6-month period, an average 172 g insecticide (Alpine aerosol + Alpine dust) was used in each apartment, a 96% reduction in pesticide usage compared to chemical only treatment reported in a similar environment. The IPM program resulted in an average of 96.8 ± 2.2% reduction in the number of bed bugs. However, elimination of bed bugs was only achieved in three lightly infested apartments (<30 bed bugs at the beginning). Elimination success was closely correlated with the level of bed bug populations.

Gram-Positive Bacteria Isolated from the Common Bed Bug,Cimex lectulariusL

The common bed bug, Cimex lectularius L., is an obligate blood-feeding ectoparasite that readily feeds on humans, resulting in rashes, dermatitis, and psychological distress. Bed bug populations have increased exponentially in the last twenty years due to increased pesticide resistance and international travel. Despite their blood-feeding and ubiquity in human habitations, bed bugs are not vectors of any known pathogen. Recent isolates of antibiotic resistant bacteria from bed bugs in a homeless shelter prompted us to identify bacteria from bed bugs in low-income housing in Maryland and Colorado and from a laboratory colony, commonly known as the Harlan strain. Using standard bacteriological techniques and amplification of the 16s ribosomal RNA (rRNA) gene, four species of Gram-positive bacteria were identified from surface swabs and whole body homogenates of bed bugs. Staphylococcus arlettae and Staphylococcus epidermidis were identified from the Harlan strain; Micrococcus and Kocuria kristinae were identified from the Colorado samples. Micrococcus species have been previously identified from bed bugs, but this is the first report of K. kristinae, S. epidermidis, and S. arlettae from this insect. As an internal control for the 16s rRNA amplification, a sequence specific to Wolbachia, the bacterial endosymbiont commonly found in bed bugs, was amplified. Using these techniques, no bacteria from the gut contents were isolated. Bacteria found commonly on human skin are closely associated with bed bugs and do not pose a risk to human health. Despite their habitats and blood-feeding behavior, bed bugs from these sites were devoid of pathogenic aerobic bacteria. The mechanisms underlying bed bug resistance to exogenous bacterial infection merit further investigation.

A residue in the transmembrane segment 6 of domain I in insect and mammalian sodium channels regulate differential sensitivities to pyrethroid insecticides

Voltage-gated sodium channels are critical for electrical signaling in the nervous system. Pyrethroid insecticides exert their toxic action by modifying the gating of sodium channels. A valine to methionine mutation in the transmembrane segment 6 of domain I (IS6) of sodium channels from tobacco budworms (Heliothis virescens) has been shown to alter channel gating and reduce insect sodium channel sensitivity to pyrethroids. A valine to leucine substitution was subsequently reported in pyrethroid-resistant bedbug populations. Intriguingly, pyrethroid-resistant mammalian sodium channels possess an isoleucine at the corresponding position. To determine whether different substitutions at this position alter channel gating and confer pyrethroid resistance, we made valine to methionine, isoleucine or leucine substitutions at the corresponding position, V409, in a cockroach sodium channel and examined the gating properties and pyrethroid sensitivity of the three mutants in Xenopus oocytes. All three mutations reduced the channel sensitivity to three pyrethroids (permethrin, cismethrin and deltamethrin). V409M, but not V409I or V409L, caused 6–7mV depolarizing shifts in the voltage dependences of both activation and inactivation. V409M and V409L slowed channel activation kinetics and accelerated open-state deactivation kinetics, but V409I did not. Furthermore, the substitution of isoleucine with valine, but not with methionine nor leucine, at the corresponding position in a rat skeletal muscle sodium channel, rNav1.4, enhanced channel sensitivity to deltamethrin. Collectively, our study highlights an important role of residues at 409 in regulating not only sodium channel gating, but also the differential sensitivities of insect and mammalian sodium channels to pyrethroids.

The bed bug problem: Past, present, and future control methods

Bed bugs are wingless hematophagous ectoparasites that have co-existed with humans since they first appeared in the caves of Mediterranean and Middle Eastern regions approximately 65 million years ago. Bed bugs are not known to transmit diseases, most probably due to the lack of sylvatic cycles. Historical control methods include some remedies, but also many useful control methods such as community-wide eradication efforts, insecticidal powders, fumigation, and rigorous cleaning. These intense eradication efforts combined with newly developed synthetic insecticides, such as DDT and malathion, almost eliminated bed bugs during the 1950s. However, there has been a resurgence in bed bug populations during the past 15years. Recent molecular evidence suggests that bed bugs did not experience a genetic bottle neck, but rather existed in isolated populations. Today, bed bugs are found to have multiple modes of insecticide resistance including reduced cuticular penetration and up-regulation of ABC transporters (ATP-binding cassette protein transporters). Currently available chemical treatments are based on pyrethroid insecticides that are not effective against many insecticide resistant bed bugs, but fumigation and dust formulations have been found to be more effective. Non-chemical control methods are most useful in community-wide integrated pest management. Future bed bug control will most likely to rely on refining the currently available methods and focusing on the research with cooperative efforts.

Evaluation of an Insecticide Dust Band Treatment Method for Controlling Bed Bugs

Current bed bug, Cimex lectularius L., control usually involves insecticide applications that pose a high risk of insecticide exposure to residents and applicators. To minimize these risks and the amount of insecticides used, we designed and evaluated a dust band treatment technique. The laboratory assay showed that 1% cyfluthrin dust treated bands are highly effective in killing bed bugs. We further evaluated this technique in bed bug infested apartments. The "dust band" treatment consisted of installing a 3.8-cm-wide fabric band on furniture legs and brushing Tempo dust (1% cyfluthrin) (Bayer Environmental Science, Research Triangle Park, NC) onto the bands. In addition, interceptors were installed under furniture legs. Alpine (0.5% dinotefuran) aerosol spray was applied directly to live bed bugs found on furniture during biweekly inspections. This treatment was compared with two other treatments: "integrated pest management" (IPM) and "control." The IPM treatment included dust bands plus the following: applying hot steam to infested furniture and surrounding areas, installing mattress encasements, applying 1% cyfluthrin dust around room perimeters, and installing interceptors under furniture legs. Alpine aerosol was applied to live bed bugs found during biweekly inspections. In the control group, the apartments received cursory treatment with insecticide sprays by the existing pest control contractor hired by the property management office. Bed bug numbers before and after treatments were determined based on biweekly interceptor counts or a combination of interceptor counts and visual inspections. From 0 to 12 wk, mean bed bug counts of the dust band, IPM, and the control treatment decreased by 95, 92, and 85%, respectively. Both dust band and IPM resulted in higher bed bug reduction than the control. There was no significant difference in the final counts between dust band and IPM treatments. An additional field experiment showed installing 1% cyfluthrin dust band and interceptors in lightly infested apartments prevented bed bug population rebound. Results indicate applying insecticide dust bands to furniture legs is an effective bed bug control technique.

Comparison of multiple steam treatment durations for control of bed bugs (Cimex lectularius L.)

The factors contributing to the current resurgence of bed bug Cimex lectularius L. populations across the United States and elsewhere include, among others, the development of resistance to chemical insecticides and population management practices. This has led to the development and attempted refinement of many non-chemical control methods that contribute to an IPM approach to solving the current bed bug population density increase in urban dwellings. One such approach is the use of heat in the form of steam to provide an effective mechanism for controlling localized infestations of bed bugs. The work reported herein was designed to refine our understanding of the duration of bed bug/steam contact necessary to affect mortality of bed bugs in laboratory trials. Beg bug eggs, nymphs and adults were exposed to three steam treatment exposure periods in these trials. Mean percentage mortality of bed bug eggs was 100% (regardless of duration of exposure), and that of nymphs and adults ranged from 88.0 to 94.0%. Survivorship of nymphs and adults in the trials was the result of experimental protocol restrictions that would not usually be associated with actual pest management efforts. The treatment equipment used in these trials is portable and relatively inexpensive and represents a non-chemical means of killing all life stages of bed bugs. While this method would likely be seen as an inefficient means of remediating a mature bed bug infestation within a structure, it does represent a practical component of integrated management of this pest insect.

Robust cuticular penetration resistance in the common bed bug (Cimex lectularius L.) correlates with increased steady-state transcript levels of CPR-type cuticle protein genes

Bed bug (Cimex lectularius L.) populations are increasing worldwide, with resistance to insecticides thought to be a major contributor. Several recent reports have documented widespread kdr-type mutations at the target site for pyrethroid insecticides, and there is substantial published evidence for metabolic resistance mediated through cytochrome P450-mediated oxidation. Here we report that resistance ratios for a bed bug strain collected in Richmond, VA, increase by three orders of magnitude when the route of insecticide treatment is changed from inoculation to topical. This increase suggests that reduced cuticular penetration plays a powerful role in bed bug resistance to insecticides. We identified 62 putative cuticle protein-encoding contigs from bed bug transcriptome data containing the Rebers and Riddiford consensus sequence. We classified these contigs as to CPR type, and compared the amino acid composition of the different types to that of the entire proteome. Quantitative PCR analysis indicated that many of these transcripts were substantially upregulated in resistant bed bugs, with some more than 20-fold higher than in the susceptible strain. These results suggest the possibility that thickening or remodeling of the bed bug cuticle may contribute to decreased insecticide penetration.

Bedbugs: A primer for the health-system pharmacist

The history and life cycle of bedbugs, the identification and supportive treatment of bedbug bites, and the eradication and prevention of bedbug infestations are reviewed. Cimex lectularius, known commonly as the bedbug, is a growing problem in the United States. While the bedbug population declined between the 1950s and the late 20th century, recent increases in international travel and immigration, the banning of dichlorodiphenyltrichloroethane, and insecticide resistance have caused a resurgence of bedbug infestations. Infestations can be identified based on clinical presentation and situational indicators such as housing location and the presence of bedbug fecal smears and nests. Chronic infestation can lead to nervousness, anxiety, and insomnia arising from the inability to identify and eradicate the problem. Scratching at the bite site can lead to a secondary bacterial infection. Because bedbugs continue to bite until the infestation is eradicated, treatment is not accomplished by one strategy alone. A team effort by different health care professionals is necessary. Because bedbugs are hardy insects, eradication can be a daunting task. Proper eradication plans should be in place at all health care facilities, and bedbug infestations should be reported to the state public health department to support the tracking and management of bedbugs. Bedbug infestations are prevalent in locations with high occupant turnover, including hospitals and health systems. Bedbug bites can cause secondary infections and lead to discomfort and anxiety in affected individuals. Pharmacists should work with other health care providers to provide affected patients with supportive treatment and ensure appropriate eradication of the infestation.

Potential population growth and harmful effects on humans from bed bug populations exposed to different feeding regimes

Effects of host availability and feeding period on bed bugs, Cimex lectularius (L.) (Hemiptera: Cimicidae), were measured. Population growth and the potential harmful effect of bed bug populations on human hosts were modelled. Bloodmeal sizes were affected by both feeding length and frequency, with >2-fold difference between insects fed daily or weekly. Blood consumption increased >2-fold between bed bugs fed occasionally and often, and 1.5-fold between occasional and daily feeding. Bed bugs fed more often than once a week, potentially every 2-4 days. Egg production was associated with nutrition, being strongly correlated with blood consumption in the previous week. Bed bug populations can grow under different feeding regimes and are hard to control with <80% mortality. Bed bugs can survive and grow even in locations with a limited blood supply, where bed bug persistence may be important for the continual spread of populations. Persistence in non-traditional locations and a potential association with human pathogens increase the health risks of bed bugs. Potential blood loss as a result of a bed bug can have serious consequences because uncontrolled populations can reach harmful levels in 3-8 months. The reproduction potential of bed bug populations suggests serious consequences to human health and the need for efficacious control measures.

Effects of juvenile hormone analog formulations on development and reproduction in the bed bug Cimex lectularius (Hemiptera: Cimicidae)

Bed bugs (Cimex lectularius L.) have become a common insect pest in urban areas and are often difficult to manage. Eradication is made more problematic by widespread insecticide resistance, raising interest in alternative control products. Juvenile hormone analogs (JHAs) such as methoprene and hydroprene are relatively harmless to non-arthropods and have proved to be effective against other urban insect pests. Two JHA products (Gentrol(®) and Precor(®), Central Life Sciences, Schaumburg, IL) were tested for efficacy against various bed bug stages as direct spray and as dry residue using three bed bug strains. At 1× and 2× the label rate, Precor(®) [active ingredient (S)-methoprene] had no significant effect on the development or fecundity of bed bugs. At 2× the label rate, confinement to residues of Gentrol(®) [active ingredient (S)-hydroprene] had no significant effect, but residues at 3× and 10× the label rate caused a reduction in fecundity and impaired development. Field strains were more susceptible to the reproductive effects of (S)-hydroprene than a long-maintained laboratory strain. While JHAs are attractive alternatives for pest management because of their inherent safety and distinct mode of action, these JHA formulations would have little impact on bed bug populations without relabeling to allow for higher application rates.

Genetic Analysis of Bed Bug Populations Reveals Small Propagule Size Within Individual Infestations but High Genetic Diversity Across Infestations From the Eastern United States

Bed bugs (Cimex lectularius L.) are a resurgent pest worldwide and infestations within the United States are increasing at a rapid rate. Because of the physical and psychological discomfort inflicted by their blood feeding habits, and allergies and secondary infections associated with bites, bed bugs are recognized as a significant public health problem. Although bed bug infestations are spreading and becoming more prevalent, we have a poor understanding of their dispersal patterns and sources of infestation. To help fill this gap, we conducted a genetic study of 21 bed bug infestations from the eastern United States, nearly all of which came from single rooms within residences. We genotyped samples comprised of 8-10 individuals per infestation at nine polymorphic microsatellite loci. Despite high genetic diversity across all infestations, with 5-17 alleles per locus (mean = 10.3 alleles per locus), we found low genetic diversity (1-4 alleles per locus) within all but one of the infestations. These results suggest that nearly all the studied infestations were started by a small propagule possibly consisting of a singly mated female and/or her progeny, or a female mated with multiple males that were highly related to her. All infestations were strongly genetically differentiated from each other (mean pairwise F(ST) between populations = 0.68) and we did not find strong evidence of a geographic pattern of genetic structure, indicating infestations located in closer proximity to each other were nearly as genetically differentiated as those located hundreds of kilometers away. The high level of genetic diversity across infestations from the eastern United States together with the lack of geographically organized structure is consistent with multiple introductions into the United States from foreign sources.

Bed Bug (Cimex lectularius L.) Population Composition as Determined by Baited Traps.

Two established field populations of bed bugs were sampled using host-mimicking traps baited with a combination of CO2, heat and a synthetic kairomone. The proportion of first instar nymphs (between 52% and 78% of all captured insects) was significantly higher than reported in previous studies, which had employed different sampling methods. The proportion of adults was correspondingly much lower than previously reported, between 5% and 7% of total capture. As many as 120 bed bugs were captured in a single trap in one night; the variation in catches between sampling locations within the same room and between days at the same location indicates that multiple nights of trapping may be required to obtain an accurate representation of population structure.