Description of a new bat-associated bug species of the Cimex lectularius group from Vietnam.

Cimex lectularius, the common bedbug is an important, emerging pest of both veterinary and medical importance. Here a recently discovered, genetically distinct new species of the C. lectularius group is described morphologically, as Cimex pulveratus Hornok sp. nov.

Discrimination between lineage-specific shelters by bat- and human-associated bed bugs does not constitute a stable reproductive barrier.

The common bed bug Cimex lectularius, has been recently shown to constitute two host races, which are likely in the course of incipient speciation. The human-associated lineage splits from the ancestral bat-associated species deep in the history of modern humans, likely even prior to the Neolithic Period and establishment of the first permanent human settlements. Hybridization experiments between these two lineages show that post-mating reproductive barriers are incomplete due to local variation. As mating takes place in off-host refugia marked by aggregation semiochemicals, the present investigation tested the hypothesis that bed bugs use these semiochemicals to differentiate between refugia marked by bat- and human-associated bed bugs; this would constitute a pre-copulation isolation mechanism. The preference for lineage-specific odors was tested using artificial shelters conditioned by a group of either male or female bed bugs. Adult males were assayed individually in four-choice assays that included two clean unconditioned control shelters. In most assays, bed bugs preferred to rest in conditioned shelters, with no apparent fidelity to shelters conditioned by their specific lineage. However, 51 % of the bat-associated males preferred unconditioned shelters over female-conditioned shelters of either lineage. Thus, bed bugs show no preferences for lineage-specific shelters, strongly suggesting that semiochemicals associated with shelters alone do not function in reproductive isolation.

IDENTIFICATION OF BAT ECTOPARASITE LEPTOCIMEX INORDINATUS FROM BAT-DWELLING CAVE, KANCHANABURI PROVINCE, THAILAND.

Bat bugs are blood-feeding insects of bats or warm blooded animals and humans. Since 2011, Leptocimex spp (Heteroptera: Cimicidae) has been reported in Thailand. However, microscopic examination of Leptocimex spp is complicated, especially when the entire body of the specimen is not available. To confirm the phenotypic identification of L. inordinatus from a limestone bat cave in Thailand, partial fragments of mitochondrial cytochrome c oxidase subunit 1 (COI) gene and 16S mitochondrial ribosomal DNA were PCR amplified and sequenced, which revealed 97% sequence identity with Cimicidae family members, being most similar to Cacodminae gen. sp. and C. vicinus, both bat bugs. Phylogenetic tree construction showed that L. inordinatus has a separate genetic lineage from that of with human bed bugs (Cimex hemipterus or C. lectularius), swallow bugs and other tick species. The presence of L. inordinatus in a bat-dwelling cave frequented by humans presents a potential public health problem requiring attention in particular regarding the possibility of zoonotic transmission of pathogens.

Genetic Variability and Geographic Diversity of the Common Bed Bug (Hemiptera: Cimicidae) Populations from the Midwest Using Microsatellite Markers.

With the recent global resurgence of the bed bugs (Cimex lectularius L.), there is a need to better understand its biology, ecology, and ability to establish populations. Bed bugs are domestic pests that feed mainly on mammalian blood. Although bed bugs have not been implicated as vectors of pathogens, their biting activity inflicts severe insomnia and allergic reactions. Moreover, they have recently developed resistance to various insecticides, which requires further molecular research to determine genetic variation and appropriate interventions. Population dynamics, including genetic differentiation and genetic distance of 10 populations from the Midwest were analyzed in this study. The bed bug samples collected by pest control companies were genotyped using eight species-specific microsatellite markers. Results showed all eight markers were polymorphic, with 8-16 alleles per locus, suggesting high genetic diversity. The FST values were >0.25, signifying pronounced genetic differentiation. The G-test results also indicated high genetic differentiation among populations. The frequency of the most common allele across all eight loci was 0.42. The coefficient of relatedness between each of the populations was >0.5, indicative of sibling or parent-offspring relationships, while the FIS and its confidence interval values were statistically insignificant within the populations tested. The populations departed from Hardy-Weinberg equilibrium, possibly because of high heterozygosity. The genetic distance analysis using a neighbor-joining tree showed that the populations from Kansas City, MO, were genetically separate from most of those from Nebraska, indicating a geographic pattern of genetic structure. Our study demonstrated the effectiveness of using microsatellite markers to study bed bugs population structure, thereby improving our understanding of bed bug population dynamics in the Midwest. Overall, this study showed a high genetic diversity and identified several new alleles in the bed bug populations in the Midwest.

[NEW FINDINGS OF BAT ECTOPARASITES (CHIROPTERA: VESPERTILIONIDAE) IN SOUTHERN SIBERIA].

The data on new findings of ectoparasites (mites and insects) of bats (Chiroptera: Vespertilionidae) in the Western Sayan and Tuva are represented. The bat fly Basilia mongolensis mongolensis Theodor, 1966 was discovered in the territory of Russia for the first time. Gamasid mite Spinturnix bregetovae Stanyukovich, 1995 is new for the region. New hosts were described for some ectoparasites.

Two different lineages of bedbug (Cimex lectularius) reflected in host specificity.

Co-speciation between host-parasite species is generally thought to result in mirror-image congruent phylogenies. For the last several centuries, many bat species have been turning synanthropic, especially those that are hosted by bedbugs in Europe. There is evidence of only limited gene flow from the population of people to the population of bats. This study was focused on comparison of survival, development, and the reproduction rate based on cross-feeding experiments. In our research, we used two bedbugs groups of Cimex lectularius-bat- and human-associated and respectively as specific/non-specific host bat and commercial human blood. Both lineages show different behavior according to their host preferences. During the bat blood experiment, we found significant differences between both human- and bat-associated bedbugs (Log rank test fourth χ(2) = 9.93, p > 0.05; fifth χ(2) = 11.33, p < 0.05), while no differences occurred with the human blood experiment between the survival levels. In molting, differences between both groups were significant particularly in the case of the bat blood experiment (fourth χ(2) = 5.91, p < 0.05). In the case of the bat blood experiment, we found a higher probability of molting in bat-associated groups than in human-associated groups. In the case of the human blood experiment, molting probability was stable in both specific and non-specific, showing similar pattern in both cases for all stages. Our results indicate an occurrence of two ecotypes within the one species C. lectularius. These findings support earlier data about morphological and mitochondrial DNA differences. The differentiation of both lineages fits the concept of specific host choice.

Mitochondrial DNA and morphology show independent evolutionary histories of bedbug Cimex lectularius (Heteroptera: Cimicidae) on bats and humans.

The bedbug, Cimex lectularius, is a well-known human ectoparasite that is reemerging after a long absence of several decades in developed countries of North America and Western Europe. Bedbugs' original hosts were likely bats, and the bedbugs are still common in their roosts. Using morphometry and sequences of mitochondrial cytochrome oxidase subunit I and 16S genes, we showed that the populations on bats and humans are largely isolated and differ in morphology. The character of the morphological difference suggests it to be due to adaptation to different hosts, namely adaptations to different sensory, feeding, and dispersal needs. Using the molecular data, we estimated the time of splitting into bat- and human-parasitizing groups using the isolation-with-migration model. The estimate is surprisingly long ago and seems to predate the expansion of modern human from Africa. The gene flow between bat- and human-parasitizing bedbugs is limited and asymmetric with prevailing direction from human-parasitizing populations to bat-parasitizing populations. The differentiation of the populations fits the concept of host races and supports the idea of sympatric speciation. Furthermore, our findings contradict recently formulated hypotheses suggesting bat roosts as a source of bedbug's resurgence as a human pest. Also, we extend the known host range of the bedbug by two bat species.

Infestation by pyrethroids resistant bed bugs in the suburb of Paris, France.

Bed bugs are hematophagous insects responsible for a re-emerging and challenging indoor pest in many countries. Bed bugs infestations may have health consequences including nuisance biting, cutaneous and systemic reactions. This resurgence can probably be attributed to factors such as increased international travel and development of resistance against insecticides. Resistance against pyrethroids has been reported several times from the USA and rarely in Europe. In France, very few data on bed bugs are available. The present study aimed to assess the infestation by bed bugs of a complex of two high-rise apartment buildings in the suburb of Paris and to evaluate their susceptibility to pyrethroid insecticides. We inspected for bed bugs 192 out of 198 apartments units (97%) and interviewed their residents. 76 (39.6%) apartments were infested. Among the 97 residents living in infested apartments, 53 (54.6%) reported bed bug bites. A total of 564 bed bugs were collected in the infested units. Bioassays showed that 54 out of 143 bed bugs were resistant to pyrethroids (37.8%; 95% confidence interval: 29.9-45.7%). DNA sequencing showed that all bed bugs tested (n=124) had homozygous L925I kdr-like gene mutation. The level of pyrethroid resistance found indicates that this phenomenon was already established in the site and prompts the need to reevaluate the wide use of pyrethroids to control bed bugs.

Insecticide resistance in bedbugs in Thailand and laboratory evaluation of insecticides for the control of Cimex hemipterus and Cimex lectularius (Hemiptera: Cimicidae).

Bedbugs are found in many countries around the world, and in some regions they are resistant to numerous insecticides. This study surveyed bedbugs in Thailand and determined their resistance to insecticides. The surveys were carried out in six provinces that attract large numbers of foreign tourists: Bangkok, Chonburi, Chiang Mai, Ubon Ratchathani, Phuket, and Krabi. Bedbugs were collected from hotels and colonized in the laboratory to evaluate their resistance to insecticides. Cimex hemipterus (F.) was found in some hotels in Bangkok, Chonburi, Phuket, and Krabi, whereas Cimex lectularius L. was found only in hotels in Chiang Mai. No bedbugs were found in Ubon Ratchathani. The colonized bedbugs showed resistance to groups of insecticides, including organochlorines (dichlorodiphenyl trichloroethane, dieldrin), carbamates (bendiocarb, propoxur), organophosphates (malathion, fenitrothion), and pyrethroids (cyfluthrin, deltamethrin, permethrin, lambda-cyhalothrin, etofenprox) in tests using World Health Organization insecticide-impregnated papers. The new insecticides imidacloprid (neonicotinoid group), chlorfenapyr (pyrrole group), and fipronil (phenylpyrazole group) were effective against the bedbugs; however, organophosphate (diazinon), carbamates (fenobucarb, propoxur), and pyrethroids (bifenthrin, cypermethrin, esfenvalerate, etofenprox) were ineffective. Aerosols containing various pyrethroid insecticides with two to four different active ingredients were effective against the bedbugs. The results obtained from this study suggested that both species of bedbugs in Thailand have developed marked resistance to various groups of insecticides, especially those in the pyrethroid group, which are the most common insecticides used for pest control. Therefore, an integrated pest management should be implemented for managing bedbugs in Thailand.

Latrocimicinae completes the phylogeny of Cimicidae: meeting old morphologic data rather than modern host phylogeny.

The family Cimicidae includes obligate hematophagous ectoparasites (bed bugs and their relatives) with high veterinary/medical importance. The evolutionary relationships of Cimicidae and their hosts have recently been reported in a phylogenetic context, but in the relevant study, one of the six subfamilies, the bat-specific Latrocimicinae, was not represented. In this study the only known species of Latrocimicinae, i.e., Latrocimex spectans, was analyzed with molecular and phylogenetic methods based on four (two nuclear and two mitochondrial) genetic markers. The completed subfamily-level phylogeny of Cimicidae showed that Latrocimicinae is most closely related to Haematosiphoninae (ectoparasites of birds and humans), with which it shares systematically important morphologic characters, but not hosts. Moreover, in the phylogenetic analyses, cimicid bugs that are known to infest phylogenetically distant bat hosts clustered together (e.g., Leptocimex and Stricticimex within Cacodminae), while cimicid subfamilies (Latrocimicinae, Primicimicinae) that are known to infest bat hosts from closely related superfamilies clustered distantly. In conclusion, adding Latrocimicinae significantly contributed to the resolution of the phylogeny of Cimicidae. The close phylogenetic relationship between Latrocimicinae and Haematosiphoninae is consistent with long-known morphologic data. At the same time, phylogenetic relationships of genera within subfamilies are inconsistent with the phylogeny of relevant hosts.

Molecular and MALDI-TOF MS identification of swallow bugs Cimex hirundinis (Heteroptera: Cimicidae) and endosymbionts in France.

BACKGROUND: The Cimicidae are obligatory blood-feeding ectoparasites of medical and veterinary importance. We aim in the current study to assess the ability of MALDI-TOF MS to identify Cimex hirundinis swallow bugs collected in house martin nests. METHODS: Swallow bugs were picked out from abandoned nests of house martin swallows and identified morphologically to the species level. The bugs were randomly selected, dissected and then subjected to MALDI-TOF MS and molecular analyses. RESULTS: A total of 65 adults and 50 nymphs were used in the attempt to determine whether this tool could identify the bug species and discriminate their developmental stages. Five adults and four nymphs of C. hirundinis specimens were molecularly identified to update our MS homemade arthropod database. BLAST analysis of COI gene sequences from these C. hirundinis revealed 98.66-99.12% identity with the corresponding sequences of C. hirundinis of the GenBank. The blind test against the database supplemented with MS reference spectra showed 100% (57/57) C. hirundinis adults and 100% (46/46) C. hirundinis nymphs were reliably identified and in agreement with morphological identification with logarithmic score values between 1.922 and 2.665. Ninety-nine percent of C. hirundinis specimens tested were positive for Wolbachia spp. The sequencing results revealed that they were identical to Wolbachia massiliensis, belonging to the new T-supergroup strain and previously isolated from C. hemipterus. CONCLUSIONS: We report for the first time to our knowledge a case of human infestation by swallow bugs (C. hirundinis) in France. We also show the usefulness of MALDI-TOF MS in the rapid identification of C. hirundinis specimens and nymphs with minimal sample requirements. We phylogenetically characterized the novel Wolbachia strain (W. massiliensis) infecting C. hirundinis and compared it to other recognized Wolbachia clades.

Morphological and Molecular Identification of Tropical Bed Bugs From Two Cities of the Pearl River Delta in China.

From the 1960s to the 1980s, with the implementation of nationwide 'Four-Pest Elimination' campaigns (bed bugs, Cimex lectularius L. and Cimex hemipterus (F.) (Hemiptera: Cimicidae), were listed as one of the targeted pests), bed bug infestations were gradually eliminated in most provinces in China. However, during the last two decades, reports of bed bug infestations in the Pearl River Delta of China have shown an upward trend. Up to now, the bed bug species occurring in this area was much less frequently reported. In this study, we used both morphological and molecular methods to accurately identify the species of bed bugs collected from the cities of Guangzhou and Foshan, China. Results indicated that no significant difference was observed in the mean pronotum width-to-length ratio of Guangzhou (2.6) and Foshan (2.4) specimens; however, both were significantly lower than that of a laboratory strain C. lectularius (3.1). The genetic distances of our specimens with C. hemipterus and C. lectularius were 0-0.2% and 22.2-22.6%, respectively. On the basis of the morphological characteristics and mitochondrial DNA sequence data, it can be affirmed that bed bugs collected from Guangzhou and Foshan were C. hemipterus.

MALDI-TOF MS identification of Cimex lectularius and Cimex hemipterus bedbugs.

Bedbugs (Cimex lectularius and C. hemipterus) have reemerged as a major public health problem around the world. Their bites cause various skin lesions as well as discomfort and anxiety. Their role as potential vectors of various infectious agents is discussed. Accordingly, all suspected cases of bedbug infestations need to be documented thoroughly, with an unequivocal identification of the arthropods involved, if any are present. Although morphological identification is easily and quickly performed by entomologists or professionals, it can be challenging otherwise. Also, distinguishing Cimex lectularius and C. hemipterus requires entomological expertise. MALDI-TOF mass spectrometry has been recently presented as an additional tool for arthropod identification. In this study, we assess the use of MALDI-TOF MS for the identification of laboratory and wild strains of C. lectularius and C. hemipterus. Several body parts of laboratory reared C. lectularius specimens were used to develop a MALDI-TOF MS protocol for bedbug identification, which was later validated using five other laboratory and wild populations of C. hemipterus and C. lectularius. A total of 167C. lectularius and C. hemipterus bedbug specimens (98 laboratory specimens and 69 wild specimens) were submitted to MALDI-TOF MS analysis. 143/167 (85.63%) provided high quality MS spectra. The in-lab database was then upgraded with a total of 20 reference spectra from all bedbug populations and the rest of the MS spectra (123 bedbugs) were blind tested. All specimens were properly identified to the species level using MALDI-TOF MS and 86,25% (69/80) were aptly identified according to their origin with LSVs ranging from 1.867 to 2.861. MALDI-TOF MS appears as a reliable additional tool for the identification of these two anthropophilic species.

Bed Bugs (Hemiptera, Cimicidae): Overview of Classification, Evolution and Dispersion.

The bed bugs (Cimex lectularius and C. hemipterus) have undergone a significant resurgence worldwide since the 1990s. A compilation of findings from a database, including 2650 scientific publications from seven major medical databases, allowed us to document main evolutionary events, from fossil evidence, dating from 11,000 years ago, until the present that has led to the current worldwide expansion of Cimicid species. We present the hypotheses on the possible dispersion pathways of bed bugs in light of the major historical and evolutionary events. A detailed classification of the Cimicidae family and finally, an illustrative map displaying the current distribution of known Cimex species in each geographical ecozone of Asia, Europe, Africa, the Americas, and Australia are presented.

Four Species of Under-reported Parasitic Arthropods in Mexico and their Potential Role as Vectors of Pathogens.

Numerous arthropod taxa are important in human and veterinary medicine. The salivary secretions and feces of arthropods can cause allergic reactions in host vertebrates or harbor pathogens. Also, bites can be a risk factor for secondary infections. Documenting the diversity of arthropods of medical and veterinary importance remains an important aspect of disease control and prevention. We provide new records of ectoparasitic arthropods from Mexico that are of potential medical or veterinary relevance. Scanning electron microscopy along with amplification and sequencing of a fragment of the mitochondrial gene (16S rRNA) was used to confirm some species identities. We report the cat louse Felicola subrostratus from cats and the chewing louse Heterodoxus spiniger from dogs, which are common ectoparasites but largely not reported in Mexico. The chigger Eutrombicula alfreddugesi is common on wild lizards (Squamata). For the first time, E. alfreddugesi is reported on Hemidactylus frenatus (common house gecko). This reptile has a close relationship with humans and its chiggers can cause dermatitis (i.e., trombiculiasis) or transmit pathogens. In addition, the common bed bug Cimex lectularius is reported for the first time in the state of Yucatan, an atypical area for its natural distribution. Phylogenetic analysis revealed that Cimex lectularius from Yucatan is closely related to genetic sequences of Cimex lectularius from China. Knowing the regional distribution of arthropods allows the design and implementation of prevention strategies for those that have potential roles as reservoirs or vectors.

Detection of seminal fluid proteins in the bed bug, Cimex lectularius, using two-dimensional gel electrophoresis and mass spectrometry.

The global increase of the human parasite, the common bed bug Cimex lectularius, calls for specific pest control target sites. The bed bug is also a model species for sexual conflict theory which suggests that seminal fluids may be highly diverse. The species has a highly unusual sperm biology and seminal proteins may have unique functions. One-dimensional PAGE gels showed 40-50% band sharing between C. lectularius and another cimicid species, Afrocimex constrictus. However, adult, sexually rested C. lectularius males were found to store 5-7 microg of seminal protein and with only 60 microg of protein we obtained informative 2-D PAGE gels. These showed 79% shared protein spots between 2 laboratory populations, and more than half of the shared protein spots were detected in the mated female. Further analysis using liquid chromatography electrospray ionization tandem mass spectrometry revealed that 26.5% of the proteins had matches among arthropods in databases and 14.5% matched Drosophila proteins. These included ubiquitous proteins but also those more closely associated with reproduction such as moj 29, ubiquitin, the stress-related elongation factor EF-1 alpha, a protein disulfide isomerase and an antioxidant, Peroxiredoxin 6.

An Early Holocene Record of Cimex (Hemiptera: Cimicidae) From Western North America.

The subfossil remains of 14 cimicids (Hemiptera: Cimicidae) were recovered during archaeological investigations of the Paisley Five Mile Point Cave site (35LK3400), an exceptionally well-dated (n = 229 radiocarbon dates) late Pleistocene-early Holocene rock shelter site in south-central Oregon. Nine of the specimens have been assigned to three modern species of Nearctic Cimicidae-Cimex antennatus Usinger & Ueshima, Cimex latipennis Usinger & Ueshima, and Cimex pilosellus (Horváth)-whereas the remaining five individuals were too fragmentary to positively identify. The chronology of the insect assemblage puts one specimen at circa 5,100 calibrated years before present (cal. yr BP), and the remaining 13 range in age from 9,400 to almost 11,000 cal. yr BP. Although fossil and subfossil cimicid remains have been recovered at other archaeological sites, the fossil record for bed bugs is largely undocumented. The Paisley Caves specimens thus far represent the oldest remains of the genus in probable contact with humans on record.

Phylogenetic analyses of bat-associated bugs (Hemiptera: Cimicidae: Cimicinae and Cacodminae) indicate two new species close to Cimex lectularius.

BACKGROUND: Bats are regarded as the primary (ancestral) hosts of bugs of the family Cimicidae. The historically and economically most important species in the family is the common bedbug (Cimex lectularius), because of its worldwide occurrence and association with humans. This molecular-phylogenetic study was initiated in order to expand the knowledge on the phylogeny of cimicid bugs of bats, by investigating samples from Hungary, Romania (representing central-eastern Europe) and two further countries (South Africa and Vietnam). RESULTS: Altogether 216 cimicid bugs were collected (73 Ci. lectularius, 133 Ci. pipistrelli, nine Cacodmus ignotus and one Ca. sparsilis). Members of the Cimex lectularius species group were found both in the environment of bats (only Myotis emarginatus, which is a cave/attic-dwelling species) and on three crevice-dwelling bat species (two pipistrelloid bats and M. bechsteinii). On the other hand, Ci. pipistrelli always occurred off-host (near M. myotis/blythii, which are cave/attic-dwelling species). In addition, two Cacodmus spp. were collected from Pipistrellus hesperidus. The morphological characters of these specimens are illustrated with high resolution pictures. Analysis of cytochrome c oxidase subunit 1 (cox1) sequences generated from 38 samples indicated relative genetic homogeneity of Ci. pipistrelli, while the Ci. lectularius group had two haplotypes (collected from pipistrelloid bats in Hungary and Vietnam) highly divergent from other members of this species group. These results were confirmed with molecular and phylogenetic analyses based on the internal transcribed spacer 2 (ITS2). Bat-associated bugs morphologically identified as Ca. ignotus and Ca. sparsilis were different in their cox1, but identical in their ITS2 sequences. CONCLUSIONS: Molecular evidence is provided here on the existence of two new genotypes, most likely new species, within the Ci. lectularius species group. The relevant specimens (unlike the others) were collected from pipistrelloid bats, therefore the association of Ci. lectularius with different bat host species (pipistrelloid vs myotine bats) should be evaluated further as a possible background factor of this genetic divergence. In addition, Ca. ignotus is reported for the first time in South Africa.

Genetic Diversity and Phylogenetic Relationships of Cytochrome C Oxidase Subunit I in Cimex hemipterus (Hemiptera: Cimicidae) Populations in Malaysia.

The tropical bed bug is scientifically recognized as a significant public health problem. While there is an increased awareness about their resurgence by medical and life science committees, efficient bed bug management still remains unresolved. The solution may soon arise, as information about bed bugs' infestation dynamics and systematics are becoming more distinguishable. Recent developments in studies about bed bugs are based on molecular intervention by determining their genetic variation and phylogeography. The aim of this study is to assess the phylogenetic relationships and genetic diversity among the populations of tropical bed bugs inhabiting Malaysia. A molecular genotyping study was conducted with 22 tropical bed bug populations composed of three individuals per population. The mitochondrial (COI) gene was used as a marker. The data obtained were analyzed using the T-Coffee, ClustalX, MEGA 6.0, and PAUP software. The results showed one main monophyletic clade that consisted of two groups: Ch01 and Ch02. Ch02 consists of samples from the Bandar Hilir population, differing from the other populations studied by one singleton base. However, as there were no changes in the amino acid, this singleton genetic variation was considered to have no effect on genetic differentiation. Ch01 shows similarity with some sequence of Cimex hemipterus (F.) from Thailand, suggesting an international diversity connection. The disparity index apparently suggests that all isolates are homogeneous populations and are supported by the low value of the mean pairwise distance between isolates. This study will increase the knowledge about phylogeographic diversity of tropical bed bug in Malaysia.

High prevalence of bedbugs Cimex hemipterus and Cimex lectularis in camps for internally displaced persons in Freetown, Sierra Leone: a pilot humanitarian investigation.

The prevalence of bedbugs Cimex hemipera and C. lectularis was investigated in camps for the internally displaced persons (IDPs) in Freetown, Sierra Leone. Two hundred and thirty eight rooms were searched during the day and at night, and 233 (98%) of those rooms in 30 booths were infested with different life cycle stages of bedbugs. There hundred and ninety-eight (68%) of the bedbugs were adults, 145 (24.8%) were nymphs of various instars, and 41 (7%) were clusters of eggs. Significantly (P > 0.05) more bedbugs were recovered during the night inspections 64.6% as compared to 35.4% during the day inspections. In addition, more adult bedbugs were recovered at night than during the day, a manifestation of their peak feeding period. Of the total of 570 adults and nymphs collected and identified, 320 (56.1%) and 250 (43.9%) were Cimex lectularis and Cimex hemipterus respectively. Clinical examination of 221 individuals living in the booths during 3 consecutive weeks of examinations and treatment for conditions suggestive of bedbug infestation (bites and skin reactions as well as treatments for other health and medical conditions) showed that 196 (86%) had wheals as a direct result of bedbug bites. The data of this pilot humanitarian investigation shows a high prevalence of bedbug infestation in these displacement camps. It is recommended that some control measures be instituted, like residual insecticide application along with integrating control methods within the primary health care system, because bedbugs are a source of great irritation and sleepless nights that could lead to stress.