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Introduction Bed bugs are hematophagous insects that can be problematic in some urban emergency departments. The objective was to determine if red blood cell (RBC) and coagulation indices of bed bug–infested emergency department (ED) patients differed from those of noninfested control patients. Methods A chart review from a single health system was performed for ED patients between February 1, 2011, and February 1, 2017. Bed bug–infested patients were matched to noninfested control patients on the basis of age, sex, and the presenting ED. Variables were analyzed with the t-test and Pearson χ2 test and were modeled with multivariable logistic regression. Results The study had 332 bed bug–infested patients and 4952 controls. Infested patients had lower hemoglobin (11.7 g/dL vs 12.8 g/dL), hematocrit (35.0% vs 37.9%), RBC counts (4.1 × 109/L vs 4.4 × 109/L), mean corpuscular volume (86.0 vs 87.5 fL/cell), and mean corpuscular hemoglobin concentrations (33.2 vs 33.7 g/dL) and higher RBC distribution width-coefficient of variation (RDW-CV) (15.2% vs 14.2%) than noninfested patients (all P ≤ .003). Infested patients were more likely to be anemic (59.5% vs 36.9%) and to have severe anemia (4.4% vs 0.7%) (P Conclusion Bed bug infestated patients in the ED are associated with anemia.

The world has experienced a major global resurgence of bed bug infestations over the past 2 decades. While bed bugs do not serve as vectors of disease, their bites and household infestations result in significant psychological distress, clinical manifestations, and economic costs. Most human bed bug infestations are caused by the “common bed bug,” Cimex lectularius, or the “tropical bed bug,” C. hemipterus. Zoonotic cimicids also occasionally feed on humans. Bites are the most commonly reported manifestation of infestations, although findings may be subtle and overlooked for some time. The bugs can be submitted to the laboratory for identification, and therefore, clinical microbiologists should be familiar with their key identifying features and how they can be differentiated from similar-appearing arthropods. This review covers the biology and epidemiology of bed bugs; aspects of laboratory collection, identification, and reporting; and the clinical implications of bed bug infestations.

Knockdown-resistance (kdr) against pyrethroids in bed bugs (Cimex lectularis) is associated with the presence of several point mutations in the voltage-sensitive sodium channel α-subunit gene and/or an increased metabolic detoxification by cytochrome P450 monooxygenases (CYPs). In the present study, pyrosequencing assays were developed to quantify the presence of the kdr substitutions (V419L or L925I substitution) in bed bugs in Berlin, Germany. In 14 of 17 bed bug field strains, pyrosequencing revealed the presence of the substitution L925I with allele frequencies between 30% and 100%. One field strain additionally carried the substitution V419L with allele frequencies of 40% in males and 96% in females. In seven of the 17 field strains, mRNA levels of four CYP genes were examined using RT-qPCR. Relative to a susceptible laboratory reference strain, five field strains showed significantly higher mRNA levels of cyp397a1 with 7.1 to 56-fold increases. One of these strains additionally showed a 4.9-fold higher mRNA level of cyp398a1 compared to the reference strain, while cyp4cm1 and cyp6dn1 showed no significant differences. Our findings indicate that multiple resistance mechanisms are present in German C. lectularius populations simultaneously., Graphical abstract Image 1, Highlights • Multiple pyrethroid resistance mechanisms in bed bugs from Germany. • Occurrence of substitutions V419L and L925I in voltage-sensitive sodium channel. • New pyrosequencing assays to quantify V419L and L925I in beg bug populations. • Increased mRNA expression levels of the cytochrome P450 genes cyp397a1 and cyp398a1.

Bed bugs (Cimex lectularius L.) are ectoparasitic wingless insects that feed on the blood of mammals, typically in residential settings. The objectives of this study were to establish a time-course of human DNA quantitation from bed bugs and to generate human DNA profile(s) of a host and/or multiple hosts from a bed bug that fed on human blood. Female human genomic DNA concentrations ranged from 18.370 to 0.195ng/bed bug at 0-108h post blood meal (PBM), male human genomic DNA concentrations ranged from 5.4 to 0.105ng/bed bug at 0-108h PBM, and pooled human female and male blood ranged from 5.49 to 0.135ng/bed bug at 0-96h PBM. Human autosomal STR complete profiles were obtained until 72h PBM for female, male, and pooled human blood. These results reveal that identification of multiple human hosts is possible from a single bed bug. However, the ratio of each contributor may be variable depending on the amount of blood ingested from each individual and the time difference of blood consumed from each subject. Average peak heights for three STR markers of low (D3S1358), medium (D13S317), and high molecular weight (D2S1338), were also compared over time. Peak heights were consistently higher for the low molecular weight marker over all time intervals. These data suggest that some markers can be successfully recovered more than three days PBM. Hence, bed bugs can serve as physical evidence in temporal and spatial predictions to match suspects and/or victims to specific locations in criminal investigations.

Patients with suspected bites or skin rashes regularly present to their primary care physician. Common mite infections encountered in the primary care office include scabies, chiggers, grain itch, and allergic responses from dust mites. In fact, scabies is one of the 50 most prevalent diseases worldwide. Bed bugs are also becoming increasingly common, living in dark crevices, such as mattresses, feeding at night, and causing a maculopapular immune mediated allergic skin response in humans. Proper identification of the mite or bed bug is essential to guide treatment and eradication.

Bed bug control highly depends on insecticides with a limited number of modes of action, especially since the global prevalence of pyrethroid resistance. De facto insecticide options against bed bugs in Japan are acetylcholinesterase inhibitors (AChEis) that consist of organophosphates and carbamates. However, the status of AChEi resistance and the mechanisms involved have not been ascertained. An amino acid substitution mutation, F348Y (or F331Y in standard numbering), occurring at an acyl-binding site of the paralogous AChE gene (p-Ace), was identified among AChEi-resistant colonies of both common and tropical bed bugs (Cimex lectularius and C. hemipterus, respectively). This mutation was genetically associated with propoxur and fenitrothion resistance in F348Y-segregating colonies of C. hemipterus. Inhibition of heterologously expressed C. lectularius p-Ace with insecticides revealed that the sensitivities of F348Y-carrying AChE decreased by orders of 10- to more than 100-fold for diazoxon, carbaryl, fenitroxon, paraoxon, chlorpyrifos-methyl, malaoxon, azamethiphos, methyl-paraoxon, and propoxur. In contrast, the mutant AChE showed a slightly decreased degree of sensitivity for dichlorvos and almost unchanged sensitivity for metoxadiazone. Further studies are needed to ascertain whether the practical efficacies of dichlorvos and metoxadiazone are ensured against F348Y-carrying bed bugs and whether other resistance mechanisms are involved.

Due in part to the development of insecticide resistance, the common bed bug, Cimex lectularius, has overcome human intervention efforts to make a global resurgence. The failure of chemical pesticides has created a need for novel strategies to combat bed bugs. While a number of insect pests are susceptible to the use of entomopathogenic microbes or microbial-derived toxins, biological control methods have not been thoroughly explored in bed bugs. Here, we tested the virulence of three entomopathogenic bacterial species in C. lectularius to determine their potential for bed bug control. We examined bed bug survival after inoculation with live or heat-killed Serratia marcescens, Pseudomonas fluorescens, and Bacillus thuringiensis israelensis at varying temperatures. We also analyzed the viability and growth of the same bacteria in infected bed bugs. All three bacterial species were pathogenic to bed bugs. However, the effects of S. marcescens and P. fluorescens were temperature-dependent while the lethality of B. thuringiensis israelensis was not. In addition, bacterial virulence was partly dependent on the route of infection but was not strongly associated with proliferation. Thus, our results suggest multiple possible mechanisms of microbial pathogenicity in the bed bug and indicate that entomopathogenic bacteria, or products derived from them, may have useful applications for bed bug control.

The common bed bug, Cimex lectularius, is an obligate blood-feeding insect that is resurgent worldwide, posing a threat to human beings through its biting nuisance and disease transmission. Bed bug aggregation pheromone is considered a very promising attractant for use in the monitoring and management of bed bugs, but as yet little is known regarding the sensory physiology of bed bugs related to this pheromone. This study examined how the individual components of aggregation pheromone are perceived by the olfactory receptor neurons (ORNs) housed in different types of olfactory sensilla in bed bugs and the molecular basis for the ORNs' responses to the aggregation pheromone. We found that the ORNs in the D olfactory sensilla played a predominant role in detecting all the components of aggregation pheromone except for histamine, which was only recognized by the C sensilla. Bed bugs' E sensilla, which include four functionally distinct groups, showed only a very weak but variant sensitivity (both excitatory and inhibitory) to the components of aggregation pheromone. Functional tests of 15 odorant receptors (ORs) in response to the components of aggregation pheromone revealed that most of these components were encoded by multiple ORs with various tuning properties. This study provides a comprehensive understanding of how bed bug aggregation pheromone is perceived and recognized in the peripheral olfactory system and will contribute useful information to support the development of synthetic attractants for bed bug monitoring and control.

The detection of urban pests, such as bed bugs, has economic and human health implications. The current methods of insect detection leveraged in daily practice include visual inspection; passive interception devices, such as sticky traps; and active monitoring traps, which exude odors that the insects are attracted to. This paper describes recent advancements related to the resonant sensing of trans-2-hexenal vapor, which offers practical utility in bed bug detection. The described sensing system includes a resonant element that is more sensitive than those reported in prior work. The work also details the method by which the functional chemistries were developed, efficiently screened, and evaluated using a multi-channel resonant sensing approach.

Indoor pests, and the allergens they produce, adversely affect human health. Surprisingly, however, their effects on indoor microbial communities have not been assessed. Bed bug (Cimex lectularius) infestations pose severe challenges in elderly and low-income housing. They void large amounts of liquid feces into the home environment, which might alter the indoor microbial community composition. In this study, using bed bug-infested and uninfested homes, we showed a strong impact of bed bug infestations on the indoor microbial diversity. Floor dust samples were collected from uninfested and bed bug-infested homes and their microbiomes were analyzed before and after heat interventions that eliminated bed bugs. The microbial communities of bed bug-infested homes were radically different from those of uninfested homes, and the bed bug endosymbiont Wolbachia was the major driver of this difference. After bed bugs were eliminated, the microbial community gradually shifted toward the community composition of uninfested homes, strongly implicating bed bugs in shaping the dust-associated environmental microbiome. Further studies are needed to understand the viability of these microbial communities and the potential risks that bed bug-associated microbes and their metabolites pose to human health.

Pyrethroid resistance has been a major hurdle limiting the effective control of bed bugs (Cimex lectularius L.). Alternative approaches that include the use of plant essential oils (EOs) have been proposed for effective management of bed bugs. However, EO resistance level comparisons between pyrethroid susceptible and resistant bed bug populations have not been previously conducted. The goal of this study was twofold: (i) determine deltamethrin resistance levels and associated resistance mechanisms in the field-collected Knoxville strain and (ii) quantify resistance levels of the Knoxville strain to five EOs (thyme, oregano, clove, geranium and coriander), their major insecticidal constituents (thymol, carvacrol, eugenol, geraniol and linalool) and an EO-based product (EcoRaider®). First, we found that the Knoxville strain was 72,893 and 291,626 fold more resistant to topically applied deltamethrin in comparison to the susceptible Harlan strain at the LD25 and LD50 lethal dose levels, respectively. Synergist bioassays and detoxification enzyme assays revealed significantly higher activity of cytochrome P450 and esterase enzymes in the resistant Knoxville strain. Further, Sanger sequencing revealed the presence of the L925I mutation in the voltage-sensitive sodium channel α subunit gene. The Knoxville strain that possesses both enzymatic and target site deltamethrin resistance, however, did not show any resistance to EOs, their major insecticidal constituents and EcoRaider® in topical bioassays (resistance ratio of ~1). In conclusion, this study demonstrated that a deltamethrin-resistant strain of bed bugs is susceptible to EOs and their insecticidal constituents.

Background We investigated a cluster of skin rashes on an inpatient adult and pediatric eating disorders treatment facility (EDTF) unit where group activities occur and include therapy dogs. Methods An epidemiological investigation was launched after scabies was diagnosed in patient A (occupying room X). An interprofessional team was engaged and included EDTF leaders, dermatology, environmental services, and infection prevention. Patient A was treated for scabies and persons with epidemiologic links were informed of possible exposure. Within two weeks, patient B (occupying room X) was evaluated by dermatology for a rash deemed inconsistent with scabies, but bed bug bites could not be excluded. Pest control professionals assessed room X for bed bugs, none were found. Four weeks later, a bed bug was visualized in room X (occupied by patient B). Pest control professionals confirmed presence of bed bugs and treated the room with high temperature heat. The investigation was expanded to persons with epidemiological links to patient B. Results 92 employees were informed of scabies exposure, no post exposure prophylaxis administered as none reported skin-to-skin contact. 55 patients had a concurrent inpatient stay with patient A. Of these, 9 had possible skin-to-skin contact and received prophylaxis. 25 were discharged and informed of possible exposure, none sought prophylaxis. Therapy dogs were examined, no fleas identified. Heat treatment cost was approximately $1000.00. There were no bedbugs identified outside room X and no additional patients with bed bug-related rashes. Investigative data supports source of bed bugs was outside the facility. Policies are under revision to restrict personal items, such as bedding, brought to EDTF. Conclusions This investigation illustrates challenges with identifying etiology of arthropod-related skin rashes in a special population and the need to reevaluate hypotheses as data unfolds over time. An interprofessional team supported timely implementation of control measures.

Bed bugs (Cimex spp.) are urban pests of global importance. Knowledge of the immune system of bed bugs has implications for understanding their susceptibility to biological control agents, their potential to transmit human pathogens, and the basic comparative immunology of insects. Nonetheless, the immunological repertoire of the family Cimicidae remains poorly characterized. Here, we use microscopy, flow cytometry, and RNA sequencing to provide a basal characterization of the circulating hemocytes of the common bed bug, Cimex lectularius. We also examine the responses of these specialized cells to E. coli exposure using the same techniques. Our results show that circulating hemocytes are comprised of at least four morphologically distinct cell types that are capable of phagocytosis, undergo degranulation, and exhibit additional markers of activation following stimulation, including size shift and DNA replication. Furthermore, transcriptomic profiling reveals expression of predicted Toll/IMD signaling pathway components, antimicrobial effectors and other potentially immunoresponsive genes in these cells. Together, our data demonstrate the conservation of several canonical cellular immune responses in the common bed bug and provide a foundation for additional mechanistic immunological studies with specific pathogens of interest.

Cimex lectularius are parasitic insects that feed on blood from a human host and are found in homes, hotels, libraries, and airports. Their behavior makes them difficult to prevent, detect, and/or treat. As well as traps and monitors, bed bug detection canines are routinely used to locate C. lectularius infestations. The role of the bed bug detector canines team has recently expanded as a potential forensic tool due to the ability to isolate human DNA from bed bugs up to three days after taking a blood meal. The effectiveness of the detector canine is in part dependent on access to target odor and for handlers understanding how to maximize target odor exposure. Little is known about the volatile organic compounds (VOCs) emitted by C. lectularius. In this study, different stages of C. lectularius were analyzed, including eggs, live adults, eggs and live adults combined, dead adults, and shed casings. VOC sampling using headspace solid-phase microextraction arrow (SPME Arrow) was performed and samples were analyzed by gas chromatography – mass spectrometry (GC–MS). The samples each had varying VOC profiles. Live and dead adult samples gave diverging profiles, providing a foundation for the success of bed bug detection canines in live targets. All samples containing eggs had the most dissimilar VOC profile. A slight increase in total VOCs was observed with increased insects present, but only after removal of volatile pheromone components. The identification of VOCs emitted by C. lectularius may help as scientific foundation to guide the development of detection canine training and certification.

Bed bugs are now one of the most prevalent human-associated, blood-feeding pests in the urban world, but few studies of their association with human pathogens have been conducted since their resurgence. Here, we used PCR to screen samples of field-collected bed bugs (Cimex spp.) for the presence of Rickettsia bacteria and we describe the first detection of an uncharacterized Rickettsia in Cimex lectularius in nature. Rickettsia was detected in 5/39 (12.8%) of the bed bug samples tested. In particular, three pools from the USA and two individual insects from the UK were positive for Rickettsia DNA. Sequencing and analysis of a fragment of the citrate synthase gene (gltA) from positive samples from each country revealed that the Rickettsia detected in both were identical and were closely related to a Rickettsia previously detected in the rat flea Nosopsyllus laeviceps. Additional experiments indicated that the Rickettsia localizes to multiple tissues in the bed bug and reaches high titres. Attempts were made to infect mammalian cells in culture but these efforts were inconclusive. Our findings suggest that Rickettsia are secondary endosymbionts of bed bugs and have potential implications for both bed bug control and public health. However, further investigation is required to determine the pathogenicity of this Rickettsia, its transmission mechanisms, and its contributions to bed bug physiology. Keywords: Bed bug, Cimex, detection, infection, pathogen, Rickettsia, symbiont

Objective To survey current bed bugs infestation status in 11 states and federal territory in Peninsular Malaysia. Methods Targeted sampling in the urban areas was performed and the sites in each state were selected based on foreign workers' abundance and reports from pest control professionals in Malaysia. The collected bed bugs were classified into different strains obtained at the respective sites. Results Out of all 185 surveyed sites, approximately 38 of them have been actively infested with one species, Cimex hemipterus (F.). A high number of collected bed bugs were found in the states of Perak (24.8%), Selangor (21.0%) and Kedah (16.1%). In terms of preferred harborages, bedding, crevices in walls and floors and cushion seats were common locations with 49.2% infestation. Bed bugs were dominantly found in dormitories of foreign workers (51.6%) compared to residential houses and public accommodations such as hotels and airports. Conclusions Migration activities and reused infested furniture probably were the possible reasons to bed bug resurgence.

Objective: To investigate some morphological and molecular characteristics of fungal parasites isolated from wild tropical bed bug, Cimex hemipterus. Methods: A series of culture methods were used to obtain fungal isolates from field-collected bed bugs. Characteristics of the isolates such as colony appearance, mycelial texture and pigmen-tation were studied to explore their morphology. Isolates were also subjected to a PCRbased genotyping test. Results: There were noticeable differences in morphological characteristics among the four isolates. Conidial areas of one isolate were dark green, whereas those of the remaining colonies were olive-green, black or dark brown. Conidia of the dark green isolate were globose, while those of olive-green, black and dark brown isolates were globose to subglobose, globose to spherical and globose to subglobose/finely roughened, respectively. These morphological specificities and the molecular analyses showed that the fungal internal transcribed spacer ribosomal region and β-tubulin gene sequences of the isolates shared clade with Trichoderma and Aspergillus sequences. Conclusions: Overall, the new discovery of common pathogens in agricultural field developed in live bed bugs storage tank may initiate the use of biological agents in later years.

Graphical abstract, Highlights • A 56-year-old woman of low-socioeconomic status with a history of mental illness was seen in an emergency department. • The patient was infested with body lice and bed bugs. • Insects were collected and tested for louse-borne pathogens but none were detected., Body lice and bed bugs are hematophagous insects that parasitize humans. Body lice are established vectors of several bacterial pathogens (e.g. Bartonella quintana, Borrelia recurrentis). Bed bugs are biologically competent vectors of some of the same agents, but their vectorial capacity for these in nature is unclear. In particular, a lack of exposure to louse-borne pathogens in bed bugs in the field could be a factor that limits their contribution to transmission. Here, we describe a case of a patient seen in an urban emergency department who was suffering from infestation with both body lice and bed bugs. Insects were collected from the patient and tested for the presence of louse-borne bacterial pathogens using 16S rRNA gene amplicon sequencing. Although no Bartonella, Borrelia, or Rickettsia were detected, this case provides evidence of ecological overlap between body lice and bed bugs and highlights several potential risk factors for co-infestation. The ecological relationships between bed bugs, body lice, and louse-borne bacteria should be further investigated in the field to determine the frequency of co-infestations and identify possible instances of pathogen infection in bed bugs.

After blood feeding on a host, bed bugs, Cimex lectularius, assemble in aggregation sites away from the host. Off-host aggregation is mediated by a combination of mechanical and chemical stimuli associated with bug feces. Partial antennectomies indicated removal of flagellomeres did not affect aggregation, but removal of the whole pedicel or its distal half significantly reduced (P

We examined the molecular and enzymatic properties of two acetylcholinesterases (AChEs; ClAChE1 and ClAChE2) from the common bed bug, Cimex lectularius. Native polyacrylamide gel electrophoresis followed by activity staining and Western blotting revealed that ClAChE1 is the main catalytic enzyme and is abundantly expressed in various tissues. Both ClAChEs existed in dimeric form connected by a disulfide bridge and were attached to the membrane via a glycophosphatidylinositol anchor. To determine their kinetic and inhibitory properties, both ClAChE1 and ClAChE2 were in vitro expressed in Sf9 cells using a baculovirus expression system. ClAChE1 showed higher catalytic efficiency toward acetylcholine, supporting the hypothesis that ClAChE1 plays a major role in postsynaptic transmission. An inhibition assay revealed that ClAChE1 is generally more sensitive to organophosphates and carbamates examined although ClAChE2 was >4000-fold more sensitive to malaoxon than ClAChE1. The relatively higher correlation between the in vitro ClAChE1 inhibition and the in vivo toxicity suggested that ClAChE1 is the more relevant toxicological target for organophosphates and carbamates. Although the physiological function of ClAChE2 remains to be elucidated, ClAChE2 also appears to have neuronal functions, as judged by its tissue distribution and molecular and kinetic properties. Our findings help expand our knowledge on insect AChEs and their toxicological properties.

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.

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 15 years. 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.

Residual biopesticide treatments of Beauveria bassiana were tested against the bed bug Cimex lectularius. An oil formulation of conidia was applied to different substrates. Bed bugs were exposed for 1 h, transferred to an unsprayed environment and monitored for mortality. Separate bioassays evaluated the effect of bed bug strain, sex, life stage, and exposure substrate on mortality. Rapid mortality was observed in all bioassays, with bed bugs exposed to treated jersey knit cotton dying most rapidly. A further assay demonstrated efficient autodissemination of conidia from exposed bed bugs to unexposed bed bugs within artificial harborages.

Bed bugs are one of the most important human ectoparasites in the United States, and a growing problem in the emergency department. We evaluated 40 emergency department (ED) patients found with a bed bug. The data show that ED patients with bed bugs are statistically more likely to be male, older, more likely to be admitted to the hospital, have higher triage emergency severity index (ESI) scores, and arrive by ambulance than the general ED patient population (p

Bed bugs must avoid detection when finding hosts and returning to hidden harborages. Their stealthy habits include foraging when hosts are asleep. Characteristics of spontaneous locomotor activity rhythm of bed bugs with different feeding histories were studied. In the absence of host stimuli, adults and nymphs were much more active in the dark than in the light. The onset of activity in the scotophase commenced soon after lights-off. The free-running period ( τ ) for all stages was longer in continuous darkness (DD) than in continuous light (LL). The lengthening of τ in DD is an exception for the circadian rule that predicts the opposite in nocturnal animals. Activity in all stages was entrained to reverse L:D regimes within four cycles. Short-term starved adults moved more frequently than recently fed adults. While bed bugs can survive for a year or more without a blood meal, we observed a reduction in activity in insects held for five weeks without food. We suggest that bed bugs make a transition to host-stimulus dependent searching when host presence is not predictable. Such a strategy would enable bed bugs to maximize reproduction when resources are abundant and save energy when resources are scarce.

Homosexual mounting is a common behaviour in bed bugs as male sexual interest is directed towards any newly fed individual. The only mode of copulation in the common bed bug, Cimex lectularius, is by traumatic insemination, where the male pierces the female abdomen with his needle-like penis. Homosexual mating would result in abdominal injuries in mounted males, as males lack the female counteradaptive spermalege structure. I here show that bed bug alarm pheromones, previously hypothesized to be a predator chemical defence, can be used by newly fed males to signal their sex and reduce the risk of homosexual mating. Mechanical blocking of the male pheromone glands significantly increased homosexual mounting duration compared to control males, while applying male extracts containing mainly alarm pheromone onto male-female mating pairs completely interrupted or shortened mating duration and reduced sperm transfer. Males confined with other males received piercing scars, demonstrating that homosexual mating occurs. The focal males in the all-male confinement experiment had reduced longevity compared to singly held males, but why this reduction in longevity occurred is not clear. Mounted males thus benefit from being able to discharge alarm pheromones, while mounting males consider the alarm signal a major sex identification cue, suggesting that male bed bugs use alarm pheromone communication to avoid homosexual harassment and mounting. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

The feeding frequency of blood-feeding invertebrates in the wild is largely unknown but is an important predictor for the potential of disease transmission and for estimating the effects blood feeding may have on the host population. We present a method to estimate the mean feeding frequency per individual parasite from the frequency distribution of fed and unfed individuals in the wild. We used three populations of the cimicid species, Afrocimex constrictus , that parasitises the fruit bat Rousettus aegyptiacus . We found that the area occupied by a bug refugium was a good predictor of the number of bugs in that refugia. The estimated parasite population sizes ranged from ca. 25,000 to 3 million bugs. Their mean abundance was 1–15 bugs per host individual. Preventing feeding by bugs in their natural habitat showed that bugs took approximately 20 days to return to an unfed stage. A formula is presented by which the distribution of digestion stages in the samples was used to calculate that A. constrictus feeds approximately every 7–10 days. The dry weight of a full blood meal was approximated as 13.3 mg. Therefore A. constrictus is estimated to draw an average of 1–28 μL blood per host per day. We suggest that any of our methods can be adjusted to be used in other haematophagous insects to estimate host and parasite population size, mean parasite abundance and blood meal size as well as mean feeding frequency in the wild, including the bed bug species that parasitise humans.

Bed bugs are small, blood-sucking insects. The common bed bug (Cimex lectularius) is reddish-brown in colour, with an oval, flattened body 1e6 mm in length when not blood engorged. It feeds on the blood of warm-blooded animals, preferably humans. Bed bugs usually bite people at night while they are asleep. Some people demonstrate little or no reaction to the bites, while others develop a range of dermatological reactions and, in rare cases, anaphylaxis. Bed bugs are not known to transmit infectious agents. Following the introduction of dichlorodiphenyltrichloroethane (DDT) in the 1950s, bed bugs virtually disappeared from the USA. However, there has been a resurgence in bedbug infestations in recent years. Pest control companies are reporting more infestations now than 10 years ago. Several explanations have been offered for this resurgence, including increased movement of people within the USA and internationally. In addition, bed bugs have developed resistance to many pesticides. The most common methods to treat bedbug infestations include application of heat, cold and/or pesticides. It is often recommended that management of bedbug infestations should be left to professionals such as pest control companies. However, some pesticide products are advertised directly to

Pentane extracts of male and female bed bugs were analyzed by gas chromatography and mass spectrometry in an effort to identify cuticular hydrocarbons. Seventeen hydrocarbons accounting for nearly 99% of the compounds eluting in the cuticular hydrocarbon region were identified. The sample contained mostly n-alkanes of 24 to 34 carbons, with odd numbered components predominating. The second major type of hydrocarbon were the 2-methylalkanes.

process from the APIC Text and EPI 201 was utilized to investigate and successfully control the outbreak. Results: Infection Control immediately initiated an Oubtreak Investigation after being notified of the situation. Control measures were implemented that included cohorting patients, enhanced environmental cleaning, education for staff, patients and visitors and controlling access to the unit. As the number of cases continued to increase additional control measures were taken. These included hand hygiene posters, disposable meal trays and supplies, implementing a vistor check-in process, and finally closing the unit to new admissions. Initial investion led to the hypothesis that Norovirus was the leading suspect as the cause of the illness. Within a week the number of new cases dropped and the unit was re-opened. Lesson Learned: This was the first time than an outbreak had occurred in this facility. Use of the 13 step Outbreak Investigaton process from the APIC Text and the reference material from the EPI 201 course had a dramatic effect in sucessfully controlling the outbreak. Several weeks later the State Department of Health Laboratory confirmed the cause as Norovirus.

A Bed Utility Grip can be positioned on the bed frame in whatever place is the most advantageous for such purposes as supporting urinary drainage bags, including double-hanger designs, and the Vitalmetric unit.

The behaviour of Cimex spermatozoa was studied in vitro in a medium developed from ripe coconut milk which initiated sperm motility and sustained sperm aggregation and disaggregation. Although sperm motility could be initiated in a variety of buffers, even in the absence of seminal fluid, oxygen was essential for initiating sperm motility. Rotenone and 2,4-dinitrophenol inhibited this initiation whereas cyanide and carbon monoxide did not. The anaerobic and aerobic nature of sperm metabolism were revealed by different gas-atmosphere experiments. Once anaerobic metabolism of sperm had been initiated in nitrogen atmosphere, it continued for a specific period even in the presence of oxygen and then the respiration subsequently shifted to oxidative pathway. These respiratory metabolic phases correspond to mesospermalege and haemocoelic phases of sperm migration in the female bug.

Sensilla on the antenna of the bed bug, Cimex lectularius, were studied with the scanning and transmission electron microscope. Those which display a tubular body in the dendrite ending are presumed to have a mechanoreceptor function (bristles of type A, flat plate of type B). Bristles of type A1 contain additional dendrites which terminate at the tip of the bristle and may be gustatory receptors. Sensilla with pores in the hair wall are supposed to have an offactory, humidity and/or temperature receptor function (pegs and hairs of types C, D, E). Hairs of type E contain receptors for the alarm pheromones of the bed bug. Special attention has been paid to the pore structures and epicuticular layers of these sensilla. Possible differences in stimulus conduction are discussed between (i) sensilla with a simple wall and pores with pore tubules (types D and E) and (ii) the ribbed pegs (type C), which have a complex wall structure and spoke channels. The immersed cones of type F have a peculiar innervation, which has not been described previously. Two dendrites are held closely together by a third flat dendrite which wraps around them in the region of the outer segment. Coupling structures were found between the central dendrites, and between these and the third enveloping dendrite. Possible functions of this unique innervation are discussed. The dendrites innervating type D are grouped in three to eight bundles by multiple sheaths. The term thecogen cell is introduced to denote the innermost of the three sheath cells of a sensillum (the outer being the tormogen and the trichogen cell) which builds the dendrite sheath during ontogeny. Comparative morphometry revealed type-specific differences in the length and diameter of the dendrites. Some axons were found to lack any glial or perineurial sheath. Microorganisms were observed in the antennal tissue of several animals.

High temperature treatment significantly reduced the reproductive rate of Cimex lectularius and simultaneously rendered their mycetomes nearly symbiote-free. The possibility that the symbiotes may affect host reproductive potential is discussed.

1. 1. The pathogenicity of flagellates to their invertebrate hosts is discussed. 2. 2. The pathogenicity of T. rangeli to R. prolixus is found to be heavy in the first nymphal instars. Bugs with infection in the hemolymph were unable to molt. 3. 3. The pathogenicity of T. rangeli in the bed bug, C. lectularius , was found to be greater than in R. prolixus . Invasion of the hemolymph was fairly rapid. 4. 4. Bugs with a heavy infection in the hemolymph carried a higher mortality than those with lighter infection. 5. 5. Mortality is probably not connected with the penetration of the gut wall, since it occurs in bugs infected directly into the hemolymph. Preliminary studies indicate that the deficiency in the concentration of certain amino acids interferes with the molting process in the infected bugs.