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Abstract Bed bugs are hematophagous arthropods that can parasitize humans. During the coronavirus disease pandemic, there has been an increase in elderly neglect. A man in his 90s came to the hospital complaining of generalized pruritus. Despite being a dependent patient, he was left alone in a home by his relatives during the pandemic. Examination revealed inflammatory nodules in addition to a live bed bug crawling over his trunk. Identifying a bed bug during consultation is an uncommon feature that can help determine a particular diagnosis. As this case shows, the need for social isolation during pandemics can contribute to elder abuse and neglect.

Bed bug infestation rate has gone through an unforeseen increase in the past decades worldwide. Their resurgence is a consequence of numerous factors, including growing population density, increased international travel and the spread of insecticide resistance. Bed bug infestation is often revealed by skin symptoms appearing after their bite in sensitive patients. Medical professionals encountering patients with bed bug bites have responsibility for recognizing the condition and for instructing patients about the necessary measures for eradication. Setting the correct diagnosis, however, is not unequivocal as several skin diseases with autoimmune, immune-mediated aetiology or other arthropod stings and bites may present with similar symptoms. In this review we provide a differential diagnostic guide and an atlas of clinical pictures assigned to the diagnoses. We highlight those dermatological findings where the possibility of bed bug bite arises and identify key elements that help in the differentiation so as to avoid unnecessary diagnostic tests and force early start of extermination. [ABSTRACT FROM AUTHOR]

Arthropods are the cause of considerable human morbidity. In spite of numerous text books and reviews published on arthropods of medical importance, this is the first paper in the world to present a comprehensive review of specimens sent to a medical entomology laboratory over an extended period. The Department of Medical Entomology at Westmead Hospital is the New South Wales reference laboratory for arthropods of medical importance. In the years 1988–2017, there were 5655 samples submitted for identification. Some 25 orders, 188 families and 177 different genera were recorded, with 170 unique species. The most common specimens included the Australian paralysis tick Ixodes holocyclus (708 specimens submitted), the bird mite Ornithonyssus bursa (506), bed bugs Cimex spp. (149), moth flies Clogmia spp. (135), head lice Pediculus capitis (105), pubic lice Pthirus pubis (91) and scabies Sarcoptes scabiei (57). In 1211 samples submitted, there was no evidence for any life stages of arthropods. For these common samples, data analysed included yearly and seasonal trends, female vs. male patient submissions and the age classes of the patients. Some species such as I. holocyclus, O. bursa, Cimex spp., Clogmia spp. and P. capitis demonstrated strong seasonal trends. In the case of the female vs. male patients, there were significant differences in submissions with O. bursa, P. capitis, P. pubis and with the samples containing no arthropod evidence. Of these, only with P. pubis did more males submit than females. Younger ages classes (<10 years) were more associated with I. holocyclus and P. capitis, older patients >70 years) with scabies, mature females (50–69 years) with samples containing no evidence of arthropods and middle‐aged adults (40–69) with the remainder of the common samples. Key diagnostic features are included for some of the more challenging arthropod species to distinguish and as well as case studies provided of situations involving unique or unusual infestations. The data provides useful information on the risks that arthropods of medical importance pose to the community and will refine educational programs. [ABSTRACT FROM AUTHOR]

Aims: To investigate the immunoglobulin (Ig) G response after being fed upon by Cimex lectularius L. Methods and Results: Participants were fed upon by three male C lectularius insects weekly for a month. Blood was obtained before the feeding and at the last feeding, which was used for immunoblots against bed bug salivary gland extract, with antihuman Immunoglobulin G (IgG) secondary antibodies. No consistent IgG changes developed in 11 humans serially fed upon by C lectularius. Two participants had new IgG responses to proteins at molecular weights of approximately 12‐13 kDa, and one had an IgG response to a protein at approximately 40 kDa. At the last study visit, more intense IgG bands to proteins at molecular weights of 12‐13 kDa had developed in 55% of participants (6/11) and at molecular weights of ≈30, ≈40 and ≈70 kDa in 45% (5/11) compared with the first study visit. Nitrophorin and apyrase were the most common C lectularius proteins identified with liquid chromatography‐tandem mass spectrometry in both crushed bed bug salivary gland extract and post–bed bug feeding extract. Conclusions: Human participants did not have consistent IgG responses to crushed C lectularius salivary gland extract. [ABSTRACT FROM AUTHOR]

Bedbugs, Cimex lectularius, have re‐gained their status as economically important insects in many parts of the world and, consequently, re‐attracted research into their biology. Standardizing age, feeding and mating status of experimental animals requires easy and reliable identification of the nymphal sex. Here, we show the angle of the pointedness of the abdomen to be a reliable sex marker in nymphal stage 5, as well as the shape of the 9th sternite, allowing rapid nymph sorting by sex. The sexual dimorphism was driven by males, not females, departing from the larval growth trajectory. [ABSTRACT FROM AUTHOR]

Background: Bedbugs are blood feeding ectoparasites of humans and several domesticated animals. There are scar-city of information about the bed bugs population throughout Iran and only very limited and local studies are available. The aim of this study is to assess the phylogenetic relationships and nucleotide diversity using partial sequences of cytochrome oxidase I gene (COI) among the populations of tropical bed bugs inhabiting Iran. Methods: The bedbugs were collected from cities located in different geographical regions of Iran. After DNA ex-traction PCR was performed for COI gene using specific primers. Then DNA sequencing was performed on PCR products for the all 15 examined samples. Results: DNA sequencing analysis showed that the all C. hemipterus samples were similar, despite the minor nucleotide variations (within the range of 576 to 697bp) on average between 5 and 10 Single nucleotide polymorphisms (SNPs). Subsequently, the results were compared with the database in gene bank which revealed close similarity and sequence homology with other C. hemipterus from other parts of the world. Conclusion: In conclusion, this study has demonstrated the ability of the COI gene to differentiate between the C. hemipterus populations from a few different locations in Iran. The current research is the first report of phylogenetic and genetic species diversity analysis conducted on C.hemipterus in Iran. These results provided basic information for further studies of molecular epidemiology, public health and pest control operators in Iran [ABSTRACT FROM AUTHOR]

Insecticide dust formulations are considered as more effective for controlling the common bed bug, Cimex lectularius (L) (Hemiptera: Cimicidae), than residual sprays. Various environmental factors may affect the efficacy of insecticide dusts. In this study, we evaluated the effect of moisture on the efficacy of three insecticide dusts against C. lectularius. Moisture was created using two methods: applying steam to insecticide dust-treated tiles and aging insecticide dust-treated tiles in chambers with various levels of relative humidity (RH). In the steam treatment, three insecticides including Cimexa (92.1% amorphous silica gel), Alpine (0.25% dinotefuran, 95% diatomaceous earth), and Tempo (1% cyfluthrin) were evaluated. Exposure to steam significantly reduced the efficacy of all three insecticide dusts. Among the three insecticides, the efficacy of Cimexa was significantly higher than Alpine and Tempo. In the different RH treatments, Cimexa treated tiles that were aged under different (52, 75, and 100%) RH conditions for 1 and 2 mo caused significantly lower mortality to C. lectularius than nonaged Cimexa. We conclude that both, a short period of exposure to steam and long-period aging in a moist environment, can significantly reduce the efficacy of insecticide dusts. Moisture needs to be considered when applying insecticide dusts for controlling bed bug infestations. [ABSTRACT FROM AUTHOR]

Background: Bed bugs as blood-sucking insects have become a public health problem in urban communities throughout the world. The objective of this study was to determine the effects of resident education and self-implementation of Integrated Pest Management (IPM) strategy for eliminating bed bug infestation in infected apartments in Ahvaz City, Iran. Methods: This interventional study was conducted in seventy apartments infested with bed bug (Cimex lectularius) in Ahvaz City, southwest Iran, during a 6-month period. The bed bug infestations reported to Health centers were inspected visually and confirmed by medical entomology experts. Then, the heads of the households were received techniques/ tools of the IPM program and trained by medical entomology experts before self-implementation of control methods. Finally, the infected apartments were inspected by the experts at 1, 3, and 6 months after intervention and data were recorded in a checklist. Results: From the seventy infected apartments, 57%, 28% and 15% were considered as low, moderate, and high level infestation respectively. The bed bug infestation was eliminated from 53 apartments (76%) after one month and it reached to 62 apartments (88%) by the end of third month. Finally, after six months of applying IPM program, bed bugs infestation was eliminated from all infected apartments (100%). Residents expressed their 100% satisfaction with applying the bed bug IPM strategy. Conclusion: Training residents to implement the IPM program can reduce pest control costs, the volume of pesticides consumed, and human exposure to chemical pesticides, resulting in increased human and environmental health and safety. [ABSTRACT FROM AUTHOR]

Background: The common bed bug, a nocturnal bloodsucking insect, is known as a human parasite and public health problem in the world. The prevalence and geographical dispersion of bed bug in Ahvaz City, southwest of Iran was measured. Methods: Spatial distribution of Cimex lectularius was determined by surveying 520 houses in 62 areas of Ahvaz City in 2017. Some information like as infested points, the concern level of the residents and allergic reaction to the insect bite were registered in a form using the secondhand instrument. Results: According to the spatial distribution map, of 62 areas, 27 of them are infested with bed bugs. Infestation is scattered throughout the city, but its focus is on the east of the Karun River. The most bed bug infestation was in Asiabad followed by Manbaab areas. Prevalence of bed bug infestation estimated 9.61% in Ahvaz city. It was 5.4% and 11.6% in apartments and single houses, respectively. The lowest and highest infestation rates based on its source were 1.35% and 9.03% in wallpaper and cracks and crevices, respectively. Bedroom and sitting room were the main harborages for bed bug in the houses. The majority of residents who had bitten by a bed bug showed various allergic reactions like redness skin, papules, vesicles, pustules and blisters. Most of the people in the infested houses (62%) were very concern about bed bug infestation. Conclusion: Public education and increasing the knowledge of people can lead to successful management, prevention and elimination of this nuisance pest. [ABSTRACT FROM AUTHOR]

Two-point mutations (V419L and L925I) on the voltage-sensitive sodium channel of bed bugs (Cimex lectularius) are known to confer pyrethroid resistance. To determine the status of pyrethroid resistance in bed bugs in Korea, resistance allele frequencies of bed bug strains collected from several US military installations in Korea and Mokpo, Jeollanamdo, from 2009-2019 were monitored using a quantitative sequencing. Most bed bugs were determined to have both of the point mutations except a few specimens, collected in 2009, 2012 and 2014, having only a single point mutation (L925I). No susceptible allele was observed in any of the bed bugs examined, suggesting that pyrethroid resistance in bed bug populations in Korea has reached a serious level. Large scale monitoring is required to increase our knowledge on the distribution and prevalence of pyrethroid resistance in bed bug populations in Korea. Based on present study, it is urgent to restrict the use of pyrethroids and to introduce effective alternative insecticides. A nation-wide monitoring program to determine the pyrethroid resistance level in bed bugs and to select alternative insecticides should be implemented. [ABSTRACT FROM AUTHOR]

Abstract The worldwide resurgence of bed bugs [both Cimex lectularius L. and Cimex hemipterus (F.)] over the past two decades is believed in large part to be due to the development of insecticide resistance. The transcriptomic and genomic studies since 2010, as well as morphological, biochemical and behavioral studies, have helped insecticide resistance research on bed bugs. Multiple resistance mechanisms, including penetration resistance through thickening or remodelling of the cuticle, metabolic resistance by increased activities of detoxification enzymes (e.g. cytochrome P450 monooxygenases and esterases), and knockdown resistance by kdr mutations, have been experimentally identified as conferring insecticide resistance in bed bugs. Other candidate resistance mechanisms, including behavioral resistance, some types of physiological resistance (e.g. increasing activities of esterases by point mutations, glutathione S-transferase, target site insensitivity including altered AChEs, GABA receptor insensitivity and altered nAChRs), symbiont-mediated resistance and other potential, yet undiscovered mechanisms may exist. This article reviews recent studies of resistance mechanisms and the genes governing insecticide resistance, potential candidate resistance mechanisms, and methods of monitoring insecticide resistance in bed bugs. This article provides an insight into the knowledge essential for the development of both insecticide resistance management (IRM) and integrated pest management (IPM) strategies for successful bed bug management.

Background: The common bed bug, a nocturnal bloodsucking insect, is known as a human parasite and public health problem in the world. The prevalence and geographical dispersion of bed bug in Ahvaz City, southwest of Iran was measured. Methods: Spatial distribution of Cimex lectularius was determined by surveying 520 houses in 62 areas of Ahvaz City in 2017. Some information like as infested points, the concern level of the residents and allergic reaction to the insect bite were registered in a form using the secondhand instrument. Results: According to the spatial distribution map, of 62 areas, 27 of them are infested with bed bugs. Infestation is scattered throughout the city, but its focus is on the east of the Karun River. The most bed bug infestation was in Asi­abad followed by Manbaab areas. Prevalence of bed bug infestation estimated 9.61% in Ahvaz city. It was 5.4% and 11.6% in apartments and single houses, respectively. The lowest and highest infestation rates based on its source were 1.35% and 9.03% in wallpaper and cracks and crevices, respectively. Bedroom and sitting room were the main harbor­ages for bed bug in the houses. The majority of residents who had bitten by a bed bug showed various allergic reactions like redness skin, papules, vesicles, pustules and blisters. Most of the people in the infested houses (62%) were very concern about bed bug infestation. Conclusion: Public education and increasing the knowledge of people can lead to successful management, prevention and elimination of this nuisance pest.

Background: Bed bugs as blood-sucking insects have become a public health problem in urban communities through­out the world. The objective of this study was to determine the effects of resident education and self-implementation of Integrated Pest Management (IPM) strategy for eliminating bed bug infestation in infected apartments in Ahvaz City, Iran. Methods: This interventional study was conducted in seventy apartments infested with bed bug (Cimex lectularius) in Ahvaz City, southwest Iran, during a 6-month period. The bed bug infestations reported to Health centers were in­spect­ed visually and confirmed by medical entomology experts. Then, the heads of the households were received tech­niques/ tools of the IPM program and trained by medical entomology experts before self-implementation of control methods. Finally, the infected apartments were inspected by the experts at 1, 3, and 6 months after intervention and data were rec­orded in a checklist. Results: From the seventy infected apartments, 57%, 28% and 15% were considered as low, moderate, and high level infestation respectively. The bed bug infestation was eliminated from 53 apartments (76%) after one month and it reached to 62 apartments (88%) by the end of third month. Finally, after six months of applying IPM program, bed bugs infestation was eliminated from all infected apartments (100%). Residents expressed their 100% satisfaction with ap­plying the bed bug IPM strategy. Conclusion: Training residents to implement the IPM program can reduce pest control costs, the volume of pesticides consumed, and human exposure to chemical pesticides, resulting in increased human and environmental health and safety.

Wolbachia is an obligatory nutritional symbiont of the common bed bug, Cimex lectularius, providing B-vitamins to its host. The biological significance of Wolbachia to bed bugs is investigated primarily by eliminating the symbiont with antibiotics, which is followed by confirmation with molecular assays. In this chapter, we describe a protocol for eliminating Wolbachia in bed bugs using the ansamycin antibiotic rifampicin (also known as rifampin) and three molecular methods to accurately detect and quantify the Wolbachia gene copies in bed bug samples. We describe the digital droplet PCR (ddPCR), a highly sensitive technique for absolute quantification of low abundance target genes, which has proven to be a valuable technique for confirmation of the elimination of Wolbachia., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Bed bugs are a significant and under-studied public health nuisance. We surveyed 706 emergency department patients and found bed bug infestations were more likely (p < 0.05) among subjects having persons 19–64 years of age in the house, living in a group home, a previous history with bed bugs, and knowing someone who currently has bed bugs. Sleeping in a hotel, recent homelessness, obtaining used clothing or furniture and using a laundromat were not associated with increased risk (p > 0.05) for infestation. Individuals with less education and income were more likely (p < 0.05) to have bed bugs and express concern about getting bed bugs. Younger persons were more likely to correctly identify a picture of a bed bug compared to those over the age of 60 years (p < 0.001). [ABSTRACT FROM AUTHOR]

Most field studies on Cimex lectularius are conducted in residential or hospitality industrial settings. Cimex lectularius infestations in office settings are reported, but are rarely studied. An office environment (~875 m2) consisting of 105 cubicles or pod-seating areas with persistent C. lectularius sightings over a 2-yr period was evaluated for 90 d through intensive trapping to determine C. lectularius distribution and to eliminate the infestation. The study area was partially occupied during the study period. Two treatments of amorphous silica dust (112.5 g dust in total) were applied 29 and 57 d after the first day of monitoring. A total of 32 C. lectularius were captured by interceptors over a period of 55 d. Dry ice traps captured eight additional C. lectularius. Visual inspections identified one chair with live C. lectularius and eggs. The infestation was eliminated on 69 d after initial installation of interceptors. Spatial analysis using Ripley's K and L functions showed a high level of aggregation up to a 15 meter scale. Dispersal of C. lectularius in office settings was limited. Intensive trapping plus limited insecticide dust treatments effectively detected and eliminated C. lectularius. [ABSTRACT FROM AUTHOR]

Not all encounters with pathogens are stochastic and insects can adjust their immune management in relation to cues associated with the likelihood of infection within a life cycle as well as across generations. In this study we show that female insects (bed bugs) up-regulate immune function in their copulatory organ in anticipation of mating by using feeding cues. Male bed bugs only mate with recently fed females and do so by traumatic insemination (TI). Consequently, there is a tight temporal correlation between female feeding and the likelihood of her being infected via TI. Females that received predictable access to food (and therefore predictable insemination and infection cycles) up-regulated induced immunity (generic antibacterial activity) in anticipation of feeding and mating. Females that received unpredictable (but the same mean periodicity) access to food did not. Females that anticipated mating-associated immune insult received measurable fitness benefits (survival and lifetime reproductive success) despite laying eggs at the same rate as females that were not able to predict these cycles. Given that mating is a time of increased likelihood of infection in many organisms, and is often associated with temporal cues such as courtship and/or feeding, we propose that anticipation of mating-associated infection in females may be more widespread than is currently evidenced. [ABSTRACT FROM AUTHOR]

The global resurgence of the bed bug (Cimex lectularius L.) and the widespread resistance of this insect to pyrethroid insecticides have created the need to find alternatives to chemical control. Thus, synthetic or natural repellents have been considered as a suitable choice to control bed bug infestations. Repellents not only keep insects away from their hosts, but also allow a decrease in insecticide selection pressure. The aim of this study was to evaluate the repellence effectivity of DEET against two bed bug colonies from Argentina (a susceptible one and a field-collected pyrethroid-resistant one), under two starving periods. We found different repellent effects of DEET on the two C. lectularius colonies and no differences between the two starving periods. In fact, DEET had a lower effect on the insecticide-resistant colony. The methodology used in this study proved to be useful to test the variation of the effect of DEET between pyrethroid-susceptible and -resistant bed bugs. [ABSTRACT FROM AUTHOR]

To determine whether volatiles from bed bug eggs were similar to the defensive secretions from nymphs and adults, headspace volatiles from eggs of the common bed bug (Cimex lectularius L.) were collected by aeration, daily until hatch, and subsequently analyzed by gas chromatography–mass spectrometry. We now report that eucalyptol (1,8-epoxy- p -menthane) was identified from all egg samples. Blank control samples containing no eggs had no evidence of eucalyptol. Positive controls, containing nymphs, adults, and fecal deposits, showed the presence of the defensive secretions (E)-2-hexenal and (E)-2-octenal, but no eucalyptol. The lack of detectable (E)-2-hexenal and (E)-2-octenal in viable egg samples and the detection of eucalyptol are discussed in relation to canine detection of bed bugs. [ABSTRACT FROM AUTHOR]

The common bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), is an obligate hematophagous insect that has resurged worldwide since the early 2000s. Bed bug control is largely based on the widespread, intensive application of pyrethroid-based insecticide formulations, resulting in the emergence of insecticide-resistant bed bug populations. Insecticide resistance is frequently linked to metabolic detoxification enzymes such as cytochrome monooxygenase (P450s), esterases, glutathione S-tranferase, and carboxylesterase. Therefore, one way to overcome insecticide resistance could be the formulation of insecticides with synergists that counteract metabolic resistance. To test this hypothesis, we evaluated the impact of four synergists—piperonyl butoxide (PBO), diethyl maleate (DEM), S,S,S-tributyl phosphorotrithioate (DEF), and triphenyl phosphate (TPP)—on deltamethrin efficacy in two pyrethroid-resistant bed bug strains. A statistically significant difference in synergism ratios (SR) of a highly resistant field-derived strain (Jersey City, resistance ratio [RR] = 20,000) was noted when any of the four synergists (PBO SR = 20.5; DEM SR = 11.7; DEF SR = 102.3; and TPP SR = 9.7) were used with deltamethrin. In a less deltamethrin-resistant strain, Cincinnati (RR = 3,333), pretreatment with PBO and DEM significantly synergized deltamethrin (PBO SR = 158.8; DEM = 58.8), whereas application of DEF and TPP had no synergistic effect. The synergism data collected strongly suggest that detoxification enzymes play a significant role in the metabolic mechanisms that mediate deltamethrin resistance in bed bugs. The development and use of safe metabolic synergists that suppress detoxification enzymes offers an interesting avenue for the management of insecticide-resistant field populations. [ABSTRACT FROM AUTHOR]

Bed bugs are globally important pests and there is an ongoing need for the development and improvement of bed bug control tools. Though promising against other insect pests, the exploration of biological methods for bed bug control is limited. Previously, we identified several species of bacteria that have entomopathogenic effects against bed bugs when ingested. We also described the conservation of several antibacterial responses in bed bugs, including the expression of immune effector genes regulated by NF-kB transcription factors through the Toll and immune deficiency (IMD) signaling pathways. Accordingly, we predicted that chemical inhibition of NF-kB signaling could reduce bed bug resistance to orally provisioned entomopathogenic bacteria, potentially improving their effectiveness as biological control agents. In the present study, we administered four small molecule inhibitors of NF-kB signaling (BMS345541, IKK16, IMD0354, Takinib) to bed bugs by feeding them in a blood meal. We then quantified basal mortality and mortality in response to oral infection with two different entomopathogenic bacteria (Pseudomonas entomophila and Bacillus thuringiensis israelensis). None of the NF-kB signaling inhibitors tested increased mortality above control levels when administered alone, suggesting a lack of direct toxicity. However, one inhibitor (IKK16) significantly enhanced the rate of mortality from oral infection with P. entomophila. Enhanced mortality was independent of direct effects of IKK16 on P. entomophila growth in vitro but was associated with higher bacterial loads in vivo (i.e., reduced resistance). Together, these results provide new insight into the regulation of the bed bug immune system and suggest that administration of entomopathogens in combination with inhibition of immune signaling pathways to reduce infection resistance may be effective for biological control of bed bugs.

Introduction . Bed bugs belong to the family Cimicidae, which includes two cosmopolitan species: Cimex lectularius and Cimex hemipterus. Bed bugs feed on the blood of humans and animals. As a result of bites, skin changes can manifest as itchy spots, erythematous-edematous lesions, hives and bullae. Aim . To describe two cases: a father and daughter living in the same household, both having skin lesions after bed bug bites that could imitate autoimmune bullous diseases. Case reports. The first case concerns a 57-year-old man on whose trunk and extremities were erythematous-edematous lesions and bullae. The second case concerns the 34-year-old daughter of the first patient, on whose trunk and extremities were linear erythematous-edematous lesions. Both in the first and second case direct and indirect immunofluorescence was negative. Conclusions. Bed bug bites can mimic other skin diseases, including autoimmune bullous diseases.

Bed bugs produce volatile aldehydes that have alarm and aggregation functions. Using two synanthropic bed bug species, Cimex lectularius L. and C. hemipterus (Fabricius), developmental changes were examined for (E)-2-hexenal, 4-oxo-(E)-2-hexenal, (E)-2-octenal, and 4-oxo-(E)-2-octenal, the four most abundant aldehydes shared between the two species. Quantitative analyses of the aldehydes in the nymphal exuviae indicated that the aldehydes’ ratio remained similar throughout nymphal development. In general, (E)-2-octenal was most abundant, and (E)-2-hexenal and 4-oxo-(E)-2-octenal were least abundant. The fourth aldehyde, 4-oxo-(E)-2-hexenal, was present in intermediate quantities. The quantities and percent abundances of the aldehydes in nymphal exuviae and the adults were significantly different between C. lectularius and C. hemipterus. The ratio between (E)-2-hexenal and (E)-2-octenal was determined in adult male and female bed bugs of each species. Adult C. hemipterus had a higher proportion of (E)-2-hexenal than C. lectularius, while no sex differences were found. This work provides the first systematic quantification of four aldehydes [(E)-2-hexenal, 4-oxo-(E)-2-hexenal, (E)-2-octenal and 4-oxo-(E)-2-octenal] for all five of the nymphal stages for both C. lectularius and C. hemipterus.

The tropical bed bug, Cimex hemipterus (F.), has now emerged as an important public health pest in the tropics. Despite its alarming infestation rate, the information on its population genetics remains scarce. Here, we described the infestation structure and population dynamics of C. hemipterus in the tropics, especially Malaysia and Singapore, based on eight novel microsatellites and two mtDNA markers, including cytochrome c oxidase I (COI) and 16S rRNA genes. Across populations, microsatellite data revealed high genetic diversity with significant genetic differentiation and restricted gene flow. Analysis within populations revealed evidence of a recent bottleneck. Nonetheless, elevated genetic diversity in nearly all populations suggests that the propagule in C. hemipterus populations were much diverse, distantly related (mean r = 0.373), and not significantly inbred (mean FIS = 0.24) than that observed in Cimex lectularius from previous studies. We observed seven mtDNA haplotypes across the 18 populations studied (Hd = 0.593) and several populations displayed more than one matrilineal descent. The two markers were generally congruent in suggesting a common, genetically diverse (especially at the nuclear region) source population with possibilities of multiple introductions for the bed bug populations in the present study.

Two strains of the common bed bug, Cimex lectularius L., eggs and first instars collected from pyrethroid-resistant adults were evaluated for insecticide resistance and compared to a susceptible strain. Dose-response bioassays were conducted using two insecticide formulations (Temprid: imidacloprid/β-cyfluthrin, and Transport: acetamiprid/ bifenthrin). The lethal concentration (LC50) for the two resistant egg strains exposed to imidacloprid/β-cyfluthrin ranged from 3 to 5-fold higher than susceptible strain eggs. Resistant strain eggs dipped into formulations of acetamiprid/bifenthrin had LC50 values which were significantly greater (39 to 1,080-fold) than susceptible strain eggs. Similar to eggs, resistant strain first instars exposed to residual applications of imidacloprid/β-cyfluthrin had LC50 values ranging from 121 to 493-fold greater than susceptible strain first instars. When resistant strain first instars were treated with acetamiprid/bifenthrin, they had LC50 values that were 99 to >1,900-fold greater than susceptible strain first instars. To determine differences between egg and first instar resistance, stage resistance ratios (SRR) were compared between the two stages. There was little difference between the egg and first instar stages, indicated by small SRR values ranging from 1.1 to 10.0. This study suggests that insecticide resistance is expressed early during bed bug development.

Bed bugs, Cimex lectularius L., are a major pest in the urban environment. Their presence often results in physical, psychological, and financial distress of homeowners and apartment dwellers. Although many insecticide bioassays have been performed on this pest, little attention has been paid to bed bug feeding status, which is closely linked to metabolism, molting, and mass. Therefore, we evaluated the toxicity of topically applied deltamethrin on insecticide susceptible adult male bed bugs fed 2 d, 9 d, and 21 d prior to testing. When toxicity was evaluated on a “per-bug” basis, there was no difference between 2 d [LD50 = 0.498 (0.316 − 0.692) ng·bug−1] and 9 d [LD50 = 0.572 (0.436 − 0.724) ng·bug−1] starved bugs, while 21 d starved bugs had a significantly lower LD50 [0.221 (0.075 − 0.386) ng·bug−1]. When toxicity was evaluated in terms of body mass, 9 d starved bugs had the highest LD50 values [0.138 (0.102 − 0.176) ng·mg−1], followed by 2 d starved bugs [0.095 (0.060 − 0.134) ng·mg−1], and then 21 d starved bugs [0.058 (0.019–0.102) ng·mg−1]; the LD50 values of 2 d and 9 d starved bugs were significantly different from 21 d starved bugs. These results indicate that feeding status plays an important role in the toxicity of deltamethrin. In addition, the lack of differences between 2 d and 9 d starved bugs indicate that the blood meal itself has little impact on tolerance, but rather it is some physiological change following feeding that confers increased tolerance to bed bugs.

Cimex lectularius, known as the common bed bug, is a widespread hematophagous human ectoparasite and urban pest that is not known to be a vector of any human infectious disease agents. However, few studies in the era of molecular biology have profiled the microorganisms harbored by field populations of bed bugs. The objective of this study was to examine the viruses present in a large sampling of common bed bugs and related bat bugs (Cimex pipistrelle). RNA sequencing was undertaken on an international sampling of > 500 field-collected bugs, and multiple workflows were used to assemble contigs and query these against reference nucleotide databases to identify viral genomes. Shuangao bed bug virus 2, an uncharacterized rhabdovirus previously discovered in Cimex hemipterus from China, was found in several bed bug pools from the USA and Europe, as well as in C. pipistrelle, suggesting that this virus is common among bed bug populations. In addition, Shuangao bed bug virus 1 was detected in a bed bug pool from China, and sequences matching Enterobacteria phage P7 were found in all bed bug pools, indicating the ubiquitous presence of phage-derived elements in the genome of the bed bug or its enterobacterial symbiont. However, viral diversity was low in bed bugs in our study, as no other viral genomes were detected with significant coverage. These results provide evidence against frequent virus infection in bed bugs. Nonetheless, our investigation had several important limitations, and additional studies should be conducted to better understand the prevalence and composition of viruses in bed bugs. Most notably, our study largely focused on insects from urban areas in industrialized nations, thus likely missing infrequent virus infections and those that could occur in rural or tropical environments or developing nations., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

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. [ABSTRACT FROM AUTHOR]

Boric acid has been used as an insecticide in the successful control of agricultural, public health and urban pests long before the advent of synthetic organic pesticides. Boric acid products, formulated as dusts, sprays, granular baits, pastes, gels, and liquids, are widely available to consumers and pest management professionals, especially to control pest infestations within homes. Boric acid dust is commonly used against bed bugs (Cimex lectularius L. [Hemiptera: Cimicidae]), but its efficacy has not been demonstrated. We evaluated the efficacy of boric acid as an ingestible and residual contact insecticide on bed bugs, and compared its efficacy on the German cockroach (Blattella germanica L. [Blattodea: Ectobiidae]) which is known to be susceptible to boric acid by both routes. Dose–response studies of 0–5% boric acid in blood demonstrated that ingested boric acid caused rapid mortality at concentrations of ≥2%, and even 0.5% and 1% boric acid caused 100% mortality, albeit at a slower time course. In contrast, bed bugs survived contact with high concentrations of boric acid dust. Smaller boric acid particles did not increase mortality of either unfed or recently fed bed bugs. The same boric acid products were effective at causing mortality of German cockroaches by both contact and ingestion. We thus conclude that although boric acid is an excellent candidate active ingredient for an ingestible bait formulation, residual applications of dust or spray would be ineffective in bed bug interventions. [ABSTRACT FROM AUTHOR]

Abstract The common bed bug, Cimex lectularius , possesses a cholinesterase expressed exclusively in the salivary gland (ClSChE). In this study, we investigated the molecular forms, tissue distribution patterns and biochemical properties of ClSChE and showed that ClSChE exists as a soluble monomeric form or a soluble dimeric form connected by a disulfide bridge. Immunohistochemical analysis confirmed that ClSChE was expressed in the epithelial cells of both the salivary gland and the duct. In addition, the secretion of monomeric ClSChE through the proboscis during feeding was confirmed by western blotting using a ClSChE-specific antibody. To predict the role of ClSChE injected into the tissue of an animal host, we analyzed the extent of hydrolysis of acetylcholine (ACh) by ClSChE by ultra-performance liquid chromatography-tandem mass spectrometry. ClSChE binding to ACh was not clearly resolved in the binding assay format used in this study, probably due to the weak but detectable ACh-hydrolytic activity of ClSChE. Nevertheless, kinetic analysis revealed that ClSChE possesses extremely low K m (high affinity to ACh) and V max values. These findings suggest that ClSChE functions virtually as an ACh-sequestering protein by having a very strong affinity to ACh but an extremely long turnover time. Given that ACh regulates a wide variety of host physiologies, we discuss the tentative roles of ClSChE in blood vessel constriction and itch/pain regulation in the host. Graphical abstract Image 1 Highlights • ClSChE is expressed in the epithelial cells of both salivary gland and duct. • Monomeric form of ClSChE is secreted through proboscis during feeding. • UPLC-MS/MS-based kinetic analysis reveals extremely low K m and V max of ClSChE. • ClSChE appears to function virtually as acetylcholine-sequestration protein. • Putative roles of ClSChE in blood feeding are discussed. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Bed bugs, Cimex lectularius L., have become one of the most difficult urban pests to control. Steam treatment is reported to be an effective method to kill bed bugs and is considered to be an important component of bed bug integrated pest management (IPM). We evaluated and compared the efficacies of two affordable consumer‐grade commercial steamers and a commonly used professional‐grade steamer for killing bed bugs. RESULTS: In laboratory experiments, the consumer‐grade steamers at affordable prices achieved the same high control efficacy as the professional‐grade steamer for treating bed bugs exposed on mattresses (100% bed bug mortality for all steamers), located beneath a fabric cover (>89% bed bug mortality for all steamers), or hiding in cracks (100% bed bug mortality for all steamers). Bed bugs located behind a leather cover did not suffer significant mortality from steam treatment regardless of the type of steamers used and the treatment duration. CONCLUSION: Proper use of steamers can kill all life stages of bed bugs. Affordable consumer‐grade steamers are as effective as professional‐grade steam machines for eliminating bed bugs resting on mattresses and hiding behind fabric materials or in cracks. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Bed bugs are one the most troublesome household pests that feed primarily on human blood. RNA interference (RNAi) is currently being pursued as a potential tool for insect population management and has shown efficacy against some phytophagous insects. We evaluated the different techniques to deliver dsRNA specific to bed bug muscle actin (dsactin) into bed bugs. Initially, stability of dsRNA in human blood was studied to evaluate the feasibility of feeding method. Adult bed bugs were injected with dsRNA between last thoracic segment and first abdominal segment on the ventral side, with a dose of 0.2 μg dsactin per insect. In addition to injection, dsactin was mixed in acetone and treated topically in the abdomens of fifth stage nymphs. We found the quick degradation of dsRNA in blood. Injection of dsactin caused significant depletion of actin transcripts and substantial reduction in oviposition and lethality in female adults. Topically treated dsRNA in fifth stage nymphs had no effect on actin mRNA expression and survival. Our results demonstrated that injection is a reliable method of dsRNA delivery into bed bugs while topical treatment was not successful. This research provides an understanding on effective delivery methods of dsRNA into bed bugs for functional genomics research and feasibility of the RNAi based molecules for pest management purposes. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

An insect egg is one of the most vulnerable stages of insect life, and the evolutionary success of a species depends on the eggshell protecting the embryo and the egg glue securing the attachment. The common bed bug (Cimex lectularius), notorious for its painful and itchy bites, infests human dwellings to feed on blood. They are easier to find these days as they adapt to develop resistance against commonly used insecticides. In this study, we identify and characterize the eggshell protein and the probable egg glue protein (i.e. keratin associated protein 5–10 like protein) of the bed bug by using mass spectrometry and bioinformatics analysis. Furthermore, by using transcription profiling and in vivo RNA interference, we show evidences that the keratin associated protein 5–10 like protein functions as the glue protein. Finally, structural characterizations on the two proteins are performed using recombinant proteins. Amino acid sequences of various insect eggshell and egg glue proteins support their independent evolution among different insect groups. Hence, inhibiting the function of these proteins related to the earliest stage of life can achieve species-specific population control. In this respect, our results would be a starting point in developing new ways to control bed bug population. [ABSTRACT FROM AUTHOR]

As the most extensively used chemical repellent, N,N-diethyl-3-methylbenzamide (DEET) displayed repellency to a wide range of insects, including the common bed bug, Cimex lectularius. While the neuronal or molecular basis involved in DEET's repellency have been majorly focused on mosquitos and fruit flies, DEET's repellency to the common bed bug is largely unreached. To gain new insights into the cellular and molecular mechanisms in DEET's repellency to the common bed bug, we characterized the neuronal response of bed bugs to DEET, identified the olfactory receptors targeted by DEET and demonstrated the interfering effect of DEET on bed bug's responses to human odorants. High doses of DEET were required for activating the olfactory receptor neurons in the sensilla of bed bugs and at least three DEET-sensitive receptors were functionally deciphered. These DEET-sensitive receptors presented even more sensitive to certain botanical terpenes/terpenoids which also displayed repellency at varying levels for bed bugs. In addition, DEET produced a blocking effect on the neuronal responses of bed bugs to specific human odors and showed inhibitory effect on the function of odorant receptors in responding to certain human odors. Taken together, our results indicate that DEET may function as a stimulus that triggers avoidance behaviors and a molecular “confusant” for interrupting the host odor recognition in the odorant receptors of bed bugs. The receptors that coincidently responded to both synthetic DEET and botanical terpenes/terpenoids suggested that DEET probably target on receptors that originally responded to terpenes/terpenoids. This study gave novel insight into the mechanisms of DEET's repellency to bed bugs and also provided valuable information for developing new reagents for bed bug control.

Kadsura coccinea (Lem.) A.C. Smith is an evergreen, woody climbing plant that is widely distributed throughout southwest mainland China. Extracts of this plant are used in traditional Chinese medicine (TCM) for the treatment of various diseases, like cancer and dermatosis, and as an anodyne to relieve pain, while the leaves are used to treat eczema. In the current study, the toxicity of essential oil from its stem (EOKC) was studied against two strains of bed bugs (Cimex lectularius). Essential oil from the plant was obtained by hydrodistillation and analyzed by GC/MS. The major compound identified was β-caryophyllene (24.73%), followed by caryophyllene oxide (5.91%), α-humulene (3.48%), and β-pinene (2.54%). Preliminary screening was performed by topically delivering a 1 µL droplet of the treatments dissolved in acetone. At 24 h after treatment, the EOKC induced mortality rates of 61.9% and 66.7% in the Bayonne and Ft. Dix strains, respectively, at 100 µg/bug. Four major compounds—β-caryophyllene, caryophyllene oxide, α-humulene, and β-pinene—were selected based on their availability and were subjected to topical, residual, and fumigation methods. When applied topically, only β-caryophyllene induced high toxicity in both strains. None of the selected compounds induced significant toxicity in the residual and fumigation methods.