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Chow Yang Lee - One of the best experts on this subject based on the ideXlab platform.
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Insecticide resistance and resistance mechanisms in bed bugs, Cimex spp. (Hemiptera: Cimicidae)
Parasites and Vectors, 2017Co-Authors: Kai Dang, G. Veera Singham, Stephen L. Doggett, Chow Yang LeeAbstract: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.
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Differences in Climbing Ability of Cimex lectularius and Cimex Hemipterus (Hemiptera: Cimicidae)
'Oxford University Press (OUP)', 2017Co-Authors: Dae, Yun Kim, Johan Billen, Stephen L. Doggett, Chow Yang LeeAbstract:The climbing abilities of two bed bug species, Cimex lectularius L. and Cimex Hemipterus (F.), were determined by evaluating their escape rates from smooth surface pitfall traps using four commercial bed bug monitors (Verifi Bed Bug Detector, ClimbUp Insect Interceptor, BlackOut Bed Bug Detector, and SenSci Volcano Bed Bug Detector). All detectors were used in the absence of lures or attractants. Unlike C. lectularius, adult C. Hemipterus were able to escape from all traps. On the other hand, no or a low number nymphs of both species escaped, depending on the evaluated traps. Examination of the vertical friction force of adults of both species revealed a higher vertical friction force in C. Hemipterus than in C. lectularius. Scanning electron microscope micrograph observation on the tibial pad of adult bed bugs of C. Hemipterus showed the presence of a greater number of tenent hairs on the tibial pad than on that of adult C. lectularius. No tibial pad was found on the fourth and fifth instars of both species. Near the base of the hollow tenent hairs is a glandular epithelium that is better developed in adult C. Hemipterus than in adult C. lectularius. This study highlights significant morphological differences between C. lectularius and C. Hemipterus, which may have implications in the monitoring and management of bed bug infestations
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Identification of putative kdr mutations in the tropical bed bug, Cimex Hemipterus (Hemiptera: Cimicidae).
Pest management science, 2014Co-Authors: Kai Dang, David G. Lilly, Chow Yang Lee, Cheryl S. Toi, Richard Naylor, Apiwat Tawatsin, Usavadee Thavara, Stephen L. DoggettAbstract:BACKGROUND: Bed bugs [both Cimex Hemipterus (F.) and Cimex lectularius L.] are highly resistant to pyrethroids worldwide. An important resistance mechanism known as ‘knockdown resistance’ (kdr) is caused by genetic point mutations on the voltage-gated sodium channel (VGSC) gene. Previous studies have identified two point mutations (V419L and L925I) on the VGSC gene in C. lectularius that are responsible for kdr-type resistance. However, the kdr mutations in C. Hemipterus have not been investigated. RESULTS: Four novel mutations, L899V (leucine to valine), M918I (methionine to isoleucine), D953G (asparticacid to glycine) and L1014F (leucine to phenylalanine), were identified in the domain II region of the C. Hemipterus VGSC gene. This region has been widelyinvestigatedforthestudyofkdr-typeresistancetopyrethroidsinotherinsectpests.TheV419LandL925Ikdr mutations as previously identified in C.lectulariuswere not detected in C.Hemipterus. CONCLUSION:M918IandL1014Fareconsideredtobeprobablekdrmutationsandmayplayessentialrolesinkdr-typeresistance to pyrethroids in C. Hemipterus. Further studies are under way in the authors’ laboratory to determine the non-kdr-type resistance mechanisms in C.Hemipterus. ©2 014 Society of Chemical Industry
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Duplicated female receptacle organs for traumatic insemination in the tropical bed bug Cimex Hemipterus: adaptive variation or malformation?
PloS one, 2014Co-Authors: Yoshitaka Kamimura, Hiroyuki Mitsumoto, Chow Yang LeeAbstract:During mating, male bed bugs (Cimicidae) pierce the female abdomen to inject sperm using their needle-like genitalia. Females evolved specialized paragenital organs (the spermalege and associated structures) to receive traumatically injected ejaculates. In LeptoCimex duplicatus, the spermalege is duplicated, but the evolutionary significance of this is unclear. In Cimex Hemipterus and C. lectularius, in which females normally develop a single spermalege on the right side of the abdomen, similar duplication sometimes occurs. Using these aberrant morphs (D-females) of C. Hemipterus, we tested the hypothesis that both of the duplicated spermaleges are functionally competent. Scars on female abdominal exoskeletons indicated frequent misdirected piercing by male genitalia. However, the piercing sites showed a highly biased distribution towards the right side of the female body. A mating experiment showed that when the normal insemination site (the right-side spermalege) was artificially covered, females remained unfertilized. This was true even when females also had a spermalege on the left side (D-females). This result was attributed to handedness in male mating behavior. Irrespective of the observed disuse of the left-side spermalege by males for insemination, histological examination failed to detect any differences between the right-side and left-side spermaleges. Moreover, an artificial insemination experiment confirmed that spermatozoa injected into the left-side spermalege show apparently normal migration behavior to the female reproductive organs, indicating an evolutionary potential for functionally-competent duplicated spermaleges. We discuss possible mechanisms for the evolutionary maintenance of D-females and propose a plausible route to the functionally-competent duplicated spermaleges observed in L. duplicatus.
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Duplicated Female Receptacle Organs for Traumatic Insemination in the Tropical Bed Bug Cimex Hemipterus: Adaptive Variation or Malformation? PLOS One
2014Co-Authors: Yoshitaka Kamimura, Hiroyuki Mitsumoto, Chow Yang LeeAbstract:During mating, male bed bugs (Cimicidae) pierce the female abdomen to inject sperm using their needle-like genitalia. Females evolved specialized paragenital organs (the spermalege and associated structures) to receive traumatically injected ejaculates. In LeptoCimex duplicatus, the spermalege is duplicated, but the evolutionary significance of this is unclear. In Cimex Hemipterus and C. lectularius, in which females normally develop a single spermalege on the right side of the abdomen, similar duplication sometimes occurs. Using these aberrant morphs (D-females) of C. Hemipterus, we tested the hypothesis that both of the duplicated spermaleges are functionally competent. Scars on female abdominal exoskeletons indicated frequent misdirected piercing by male genitalia. However, the piercing sites showed a highly biased distribution towards the right side of the female body. A mating experiment showed that when the normal insemination site (the right-side spermalege) was artificially covered, females remained unfertilized. This was true even when females also had a spermalege on the left side (D-females). This result was attributed to handedness in male mating behavior. Irrespective of the observed disuse of the left-side spermalege by males for insemination, histological examination failed to detect any differences between the right-side and left-side spermaleges. Moreover, an artificial insemination experiment confirmed that spermatozoa injected into the left-side spermalege show apparently normal migration behavior to the female reproductive organs, indicating an evolutionary potential for functionally-competent duplicated spermaleges. We discus
Teresa Cristina Monte Gonçalves - One of the best experts on this subject based on the ideXlab platform.
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Cimidíase: descrição de dois casos na cidade do Rio de Janeiro, Brasil
Anais Brasileiros De Dermatologia, 2015Co-Authors: Fred Bernardes Filho, Teresa Cristina Monte Gonçalves, João Carlos Regazzi Avelleira, Luna Azulay-abulafia, Maria Victória Quaresma, David Rubem Azulay, Amanda Queiroz Bastos, Rj Fundação Técnico-educacional Souza Marques. Rio DeAbstract:Abstract: Bed bugs are hematophagous insects which due to their morphological and biological characteristics are able to easily adapt themselves to human households. The authors describe two cases of dermatitis caused by bed bug bites in the city of Rio de Janeiro, Brazil. Patients presented linear lesions in the usual "breakfast, lunch and dinner" arrangement, suggesting this diagnosis. A visit to their dwellings showed infestation of insects identified as Cimex Hemipterus. The knowledge of these insects by the dermatological community will contribute to an accurate diagnosis as well as subsidize the dissemination of information aiming for prevention
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Bed bug dermatitis, description of two cases in Rio de Janeiro, Brazil
Anais brasileiros de dermatologia, 2015Co-Authors: Fred Bernardes Filho, João Carlos Regazzi Avelleira, Luna Azulay-abulafia, Maria Victória Quaresma, David Rubem Azulay, Amanda Queiroz Bastos, Teresa Cristina Monte GonçalvesAbstract:Bed bugs are hematophagous insects which due to their morphological and biological characteristics are able to easily adapt themselves to human households. The authors describe two cases of dermatitis caused by bed bug bites in the city of Rio de Janeiro, Brazil. Patients presented linear lesions in the usual "breakfast, lunch and dinner" arrangement, suggesting this diagnosis. A visit to their dwellings showed infestation of insects identified as Cimex Hemipterus. The knowledge of these insects by the dermatological community will contribute to an accurate diagnosis as well as subsidize the dissemination of information aiming for prevention.
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The feeding process of Cimex lectularius (Linnaeus 1758) and Cimex Hemipterus (Fabricius 1803) on different bloodmeal sources.
Journal of Insect Physiology, 2009Co-Authors: Ricardo N. Araujo, Teresa Cristina Monte Gonçalves, Fernanda S. Costa, Nelder F. Gontijo, Marcos H. PereiraAbstract:The bedbugs Cimex lectularius and Cimex Hemipterus are obligate hematophages in all their nymphal instars as well as in the adult stage. The efficiency with which the insects obtain blood from their hosts is directly related to their population dynamics. In the present study we compared the feeding process and salivary content in individuals of these two species when fed on different blood sources or host sites, using a cibarial pump electromyogram. Females ingested more blood than males but needed longer contact time with the host to complete the meal. The bedbug C. lectularius was more efficient than C. Hemipterus in obtaining blood from mice and pigeons. With regard to the feeding site on mice, it was easier for the insects to obtain blood from the skin of the belly than that of the back. Individuals of C. Hemipterus were able to maintain the cibarial pump functioning at higher frequencies for longer periods when fed on pigeons treated with anticoagulant. Although saliva from C. lectularius contained more hemeproteins and showed more anti-clotting activity its total protein content was similar to that of C. Hemipterus. Overall, C. lectularius obtains a bloodmeal more efficiently from its hosts, which may have enabled this species to reach higher levels of infestation than C. Hemipterus.
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Notes on midgut ultrastructure of Cimex Hemipterus (Hemiptera: Cimicidae).
Journal of medical entomology, 2009Co-Authors: Dihego Oliveira Azevedo, Clóvis Andrade Neves, Jacenir Reis Dos Santos Mallet, Teresa Cristina Monte Gonçalves, José Cola Zanuncio, José Eduardo SerrãoAbstract:This work studied the ultrastructure of the midgut cells of Cimex Hemipterus Fabricius (Hemiptera: Cimicidae). The midgut of adult insects was analyzed on different days after a bloodmeal, and three anatomical regions with different digestive functions were apparent. In the anterior midgut, the digestive cells had many spherocrystals, lipid inclusions, and glycogen deposits, suggesting a role in water absorption, ion regulation, digestion, and storage of lipids and sugars. The digestive cells in the middle midgut contained secretory granules in the apical cytoplasm, lysosomes, and large amounts of rough endoplasmic reticulum, suggesting that this midgut region was active in digestive processes. The posterior midgut contained digestive cells with secretory vesicles, lysosomes, rough endoplasmic reticulum, and spherocrystals, suggesting digestion and ion/water absorption. Also, there was strong evidence that the posterior midgut may be the major site of nutrient absorption. The hematophagous heteropteran groups share many of these blood digestion mechanisms.
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Ultrastructure of the Salivary Glands in Cimex Hemipterus (Hemiptera: Cimicidae)
Journal of medical entomology, 2008Co-Authors: José Eduardo Serrão, José Cola Zanuncio, Maria Ignez Castrillon, Jacenir Reis Dos Santos-mallet, Teresa Cristina Monte GonçalvesAbstract:Cimex Hemipterus (Fabricius) is a hematophagous insect that can be an experimental host of Trypanosoma cruzi and may play a role as vector of Chagas' disease. This work analyzed the structure of the salivary glands of C. Hemipterus. The secretory portion of main salivary glands has a single oval lobe that is translucent and is formed from a simple columnar epithelium lined by muscle cells. The gland cells are high, with one or two spherical nuclei, nucleolus, and some condensed chromatin. The cell cytoplasm has a well-developed rough endoplasmic reticulum, electron lucent vesicles, lysosomes, and glycogen deposits. The apical plasma membrane has microvilli, zonula adherens, and desmosomes, whereas the basal plasma membrane has some infoldings associated with mitochondria. The duct of the main salivary glands has flattened cells. The secretory portion of the accessory salivary glands is a single vesicular lobe that is translucent and is formed from a single layer of cells that varies from flattened to cubical onto muscle cells. The cytoplasm contains a well-developed smooth endoplasmic reticulum, vacuoles of different sizes containing secretions, electron lucent, and abundant mitochondria. The baso-lateral plasma membrane of adjacent cells shows septate junctions. The duct is formed from a flattened epithelium like the duct of the principal salivary gland. The secretory cells of the main salivary glands are related to protein synthesis and transport of ions. However, the secretory cells of the accessory salivary glands are related mainly to transport of ions and water from the hemolymph to glandular lumen.
Stephen L. Doggett - One of the best experts on this subject based on the ideXlab platform.
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Differences in Climbing Ability of Cimex lectularius and Cimex Hemipterus (Hemiptera: Cimicidae).
Journal of Economic Entomology, 2017Co-Authors: Johan Billen, Stephen L. DoggettAbstract:The climbing abilities of two bed bug species, Cimex lectularius L. and Cimex Hemipterus (F.), were determined by evaluating their escape rates from smooth surface pitfall traps using four commercial bed bug monitors (Verifi Bed Bug Detector, ClimbUp Insect Interceptor, BlackOut Bed Bug Detector, and SenSci Volcano Bed Bug Detector). All detectors were used in the absence of lures or attractants. Unlike C. lectularius, adult C. Hemipterus were able to escape from all traps. On the other hand, no or a low number nymphs of both species escaped, depending on the evaluated traps. Examination of the vertical friction force of adults of both species revealed a higher vertical friction force in C. Hemipterus than in C. lectularius. Scanning electron microscope micrograph observation on the tibial pad of adult bed bugs of C. Hemipterus showed the presence of a greater number of tenent hairs on the tibial pad than on that of adult C. lectularius. No tibial pad was found on the fourth and fifth instars of both species. Near the base of the hollow tenent hairs is a glandular epithelium that is better developed in adult C. Hemipterus than in adult C. lectularius. This study highlights significant morphological differences between C. lectularius and C. Hemipterus, which may have implications in the monitoring and management of bed bug infestations.
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Insecticide resistance and resistance mechanisms in bed bugs, Cimex spp. (Hemiptera: Cimicidae)
Parasites and Vectors, 2017Co-Authors: Kai Dang, G. Veera Singham, Stephen L. Doggett, Chow Yang LeeAbstract: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.
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Differences in Climbing Ability of Cimex lectularius and Cimex Hemipterus (Hemiptera: Cimicidae)
'Oxford University Press (OUP)', 2017Co-Authors: Dae, Yun Kim, Johan Billen, Stephen L. Doggett, Chow Yang LeeAbstract:The climbing abilities of two bed bug species, Cimex lectularius L. and Cimex Hemipterus (F.), were determined by evaluating their escape rates from smooth surface pitfall traps using four commercial bed bug monitors (Verifi Bed Bug Detector, ClimbUp Insect Interceptor, BlackOut Bed Bug Detector, and SenSci Volcano Bed Bug Detector). All detectors were used in the absence of lures or attractants. Unlike C. lectularius, adult C. Hemipterus were able to escape from all traps. On the other hand, no or a low number nymphs of both species escaped, depending on the evaluated traps. Examination of the vertical friction force of adults of both species revealed a higher vertical friction force in C. Hemipterus than in C. lectularius. Scanning electron microscope micrograph observation on the tibial pad of adult bed bugs of C. Hemipterus showed the presence of a greater number of tenent hairs on the tibial pad than on that of adult C. lectularius. No tibial pad was found on the fourth and fifth instars of both species. Near the base of the hollow tenent hairs is a glandular epithelium that is better developed in adult C. Hemipterus than in adult C. lectularius. This study highlights significant morphological differences between C. lectularius and C. Hemipterus, which may have implications in the monitoring and management of bed bug infestations
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Evidence of Tolerance to Silica-Based Desiccant Dusts in a Pyrethroid-Resistant Strain of Cimex lectularius (Hemiptera: Cimicidae)
Insects, 2016Co-Authors: David G. Lilly, Cameron E. Webb, Stephen L. DoggettAbstract:Insecticide resistance in bed bugs (Cimex lectularius and Cimex Hemipterus) has become widespread, which has necessitated the development of new IPM (Integrated Pest Management) strategies and products for the eradication of infestations. Two promising options are the diatomaceous earth and silica gel-based desiccant dusts, both of which induce dehydration and eventual death upon bed bugs exposed to these products. However, the impact of underlying mechanisms that confer resistance to insecticides, such as cuticle thickening, on the performance of these dusts has yet to be determined. In the present study, two desiccant dusts, Cimexa Insecticide Dust (silica gel) and Bed Bug Killer Powder (diatomaceous earth) were evaluated against two strains of C. lectularius; one highly pyrethroid-resistant and one insecticide-susceptible. Label-rate doses of both products produced 100% mortality in both strains, albeit over dissimilar time-frames (3–4 days with Cimexa vs. 14 days with Bed Bug Killer). Sub-label rate exposure to Cimexa indicated that the pyrethroid-resistant strain possessed a degree of tolerance to this product, surviving 50% longer than the susceptible strain. This is the first study to suggest that mechanisms conferring resistance to pyrethroids, such as cuticular thickening, may have potential secondary impacts on non-synthetic insecticides, including desiccant dusts, which target the bed bug’s cuticle.
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Identification of putative kdr mutations in the tropical bed bug, Cimex Hemipterus (Hemiptera: Cimicidae).
Pest management science, 2014Co-Authors: Kai Dang, David G. Lilly, Chow Yang Lee, Cheryl S. Toi, Richard Naylor, Apiwat Tawatsin, Usavadee Thavara, Stephen L. DoggettAbstract:BACKGROUND: Bed bugs [both Cimex Hemipterus (F.) and Cimex lectularius L.] are highly resistant to pyrethroids worldwide. An important resistance mechanism known as ‘knockdown resistance’ (kdr) is caused by genetic point mutations on the voltage-gated sodium channel (VGSC) gene. Previous studies have identified two point mutations (V419L and L925I) on the VGSC gene in C. lectularius that are responsible for kdr-type resistance. However, the kdr mutations in C. Hemipterus have not been investigated. RESULTS: Four novel mutations, L899V (leucine to valine), M918I (methionine to isoleucine), D953G (asparticacid to glycine) and L1014F (leucine to phenylalanine), were identified in the domain II region of the C. Hemipterus VGSC gene. This region has been widelyinvestigatedforthestudyofkdr-typeresistancetopyrethroidsinotherinsectpests.TheV419LandL925Ikdr mutations as previously identified in C.lectulariuswere not detected in C.Hemipterus. CONCLUSION:M918IandL1014Fareconsideredtobeprobablekdrmutationsandmayplayessentialrolesinkdr-typeresistance to pyrethroids in C. Hemipterus. Further studies are under way in the authors’ laboratory to determine the non-kdr-type resistance mechanisms in C.Hemipterus. ©2 014 Society of Chemical Industry
Richard C. Russell - One of the best experts on this subject based on the ideXlab platform.
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Bed bugs: Clinical relevance and control options
Clinical Microbiology Reviews, 2012Co-Authors: Stephen L. Doggett, Pablo F. Peñas, Dominic E Dwyer, Richard C. RussellAbstract:Since the late 1990s, bed bugs of the species Cimex lectularius and Cimex Hemipterus have undergone a worldwide resurgence. These bed bugs are blood-sucking insects that readily bite humans. Cutaneous reactions may occur and can start out as small macular lesions that can develop into distinctive wheals of around 5 cm in diameter, which are accompanied by intense itching. Occasionally, bullous eruptions may result. If bed bugs are numerous, the patient can present with widespread urticaria or eythematous rashes. Often, bites occur in lines along the limbs. Over 40 pathogens have been detected in bed bugs, but there is no definitive evidence that they transmit any disease-causing organisms to humans. Anemia may result when bed bugs are numerous, and their allergens can trigger asthmatic reactions. The misuse of chemicals and other technologies for controlling bed bugs has the potential to have a deleterious impact on human health, while the insect itself can be the cause of significant psychological trauma. The control of bed bugs is challenging and should encompass a multidisciplinary approach utilizing nonchemical means of control and the judicious use of insecticides. For accommodation providers, risk management procedures should be implemented to reduce the potential of bed bug infestations.
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Bed bugs: The Australian response
Insects, 2011Co-Authors: Stephen L. Doggett, Christopher J. Orton, David G. Lilly, Richard C. RussellAbstract:Australia has experienced a sudden and unexpected resurgence in bed bug infestations from both Cimex lectularius L. and Cimex Hemipterus F. A survey in 2006 revealed that infestations had increased across the nation by an average of 4,500% since the start of the decade. In response, a multi-disciplinary approach to combat the rise of this public health pest was implemented and involved the coordinated efforts of several organizations. The key components of the strategy included the introduction of a pest management standard 'A Code of Practice for the Control of Bed Bug Infestations in Australia‘ that defines and promotes 'best practice‘ in bed bug eradication, the development of a policy and procedural guide for accommodation providers, education of stakeholders in best management practices, and research. These strategies continue to evolve with developments that lead to improvements in ‗best practice‘ while bed bugs remain problematic in Australia.
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The Resurgence of Bed Bugs, Cimex spp. (Hemiptera: Cimicidae) in Australia
Proceedings of the Sixth International Conference on Urban Pests, 2008Co-Authors: Stephen L. Doggett, Richard C. RussellAbstract:From 2001 to 2004, Australia experienced a resurgence in bed bug infestations involving both the common (Cimex lectularius) and Tropical (Cimex Hemipterus) species. It was found that all Australian mainland states had experienced an exponential rise in bed bug infestations since 2001, with an overall national increase of 4.5%. A conservative estimate of the economic impact of the resurgence was $AUS100 million. To combat the resurgence, a four point strategy was implemented. The first strategy was to better define the degree of the resurgence through a survey of professional pest managers. The second strategy was the defining of best practice in bed bug management, which led to the development in 2005 of a Code of Practice for the Control of Bed Bug infestations in Australia (CoP) (www.bedbug.org.au). The aims of the CoP were to promote best practice in the eradication of active bed bug infestations and the management of potential infestations. Education of stakeholders affected by bed bugs on best practice management as defined by the CoP was the third strategy and encompassed the production of industry publications and lectures. Research, and investigations have begun in relation to both non-chemical and chemical means of control.
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has the tropical bed bug Cimex Hemipterus hemiptera cimicidae invaded australia
Environmental Health, 2003Co-Authors: Stephen L. Doggett, Merilyn J Geary, William J Crowe, Peter Wilson, Richard C. RussellAbstract:This article provides the first published record of the tropical bed bug, C. Hemipterus in Australia and describes a dual infestation of bed bugs involving two species in a backpackers' hostel. The implications of the introduction of this pest into Australia are discussed.
S. H. P. Parakrama Karunaratne - One of the best experts on this subject based on the ideXlab platform.
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Insecticide resistance mechanisms with novel 'kdr' type gene mutations in the tropical bed bug Cimex Hemipterus.
Parasites & vectors, 2019Co-Authors: Ranindra Punchihewa, W. A. Priyanka P. De Silva, Thilini C. Weeraratne, S. H. P. Parakrama KarunaratneAbstract:The tropical bed bug, Cimex Hemipterus, is a serious indoor public health pest in tropical regions causing intense physical discomfort and mental distress to humans. At present, the application of insecticides is the major control strategy. The present study was designed to evaluate the development of resistance and resistance mechanisms in Cimex Hemipterus from Kandy district, Sri Lanka. The resistance status of the collected bed bugs was determined against the discriminative dosages of DDT, malathion, propoxur, deltamethrin and permethrin by conducting bioassays according to World Health Organization guidelines. Activities of insecticide metabolizing enzymes, i.e. esterases, glutathione S-transferases (GST) and monooxygenases, and the insensitivity of organophosphate/carbamate target site acetylcholinesterase (AChE), were evaluated by biochemical assays. Regions of the gene of the pyrethroid/DDT target site, the voltage-gated sodium channel regulatory protein (VGSC), were sequenced for possible kdr mutations. Survival percentages of bed bug population were 71, 68 and 51% for DDT, malathion and propoxur respectively. KT50 and KT90 values, calculated using log-probit mortality curves for deltamethrin were 62.55 and 123.96 h, respectively. These values were much higher for permethrin where KT50 was 201.10 h and the KT90 was beyond the detectable range. Results were compared with previous values reported for the same population in 2002. Resistance to propoxur has increased significantly from 11 to 51% with about a 20-fold increase in the number of individuals with elevated esterase mechanism. No significant change has occurred in malathion and DDT resistance, in GST and monooxygenase activities, and in AChE sensitivity for the past 14 years. Six kdr associated mutations (Y/L995H, V1010L, I1011F, L1014F, V1016E, L1017F/S) and a non-kdr associated mutation (A1007S mutation) were found from the α-region of the VGSC gene. Out of the kdr type mutations, only L1014F has been reported previously form C. Hemipterus while the others have been reported from other insects. The bed bug population has developed high resistance to propoxur with increased esterase activities. KT50 for deltamethrin and permethrin has increased 125- and 20-fold, respectively, over the period 2002 to 2016. To the authors’ knowledge, this is the first time that the possible involvement of a kdr type mutation in developing pyrethroid resistance in C. Hemipterus has been shown in Sri Lanka.
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Insecticide resistance mechanisms with novel ‘kdr’ type gene mutations in the tropical bed bug Cimex Hemipterus
Parasites & Vectors, 2019Co-Authors: Ranindra Punchihewa, W. A. Priyanka P. De Silva, Thilini C. Weeraratne, S. H. P. Parakrama KarunaratneAbstract:Background The tropical bed bug, Cimex Hemipterus , is a serious indoor public health pest in tropical regions causing intense physical discomfort and mental distress to humans. At present, the application of insecticides is the major control strategy. The present study was designed to evaluate the development of resistance and resistance mechanisms in Cimex Hemipterus from Kandy district, Sri Lanka. Methods The resistance status of the collected bed bugs was determined against the discriminative dosages of DDT, malathion, propoxur, deltamethrin and permethrin by conducting bioassays according to World Health Organization guidelines. Activities of insecticide metabolizing enzymes, i.e. esterases, glutathione S-transferases (GST) and monooxygenases, and the insensitivity of organophosphate/carbamate target site acetylcholinesterase (AChE), were evaluated by biochemical assays. Regions of the gene of the pyrethroid/DDT target site, the voltage-gated sodium channel regulatory protein (VGSC), were sequenced for possible kdr mutations. Results Survival percentages of bed bug population were 71, 68 and 51% for DDT, malathion and propoxur respectively. KT_50 and KT_90 values, calculated using log-probit mortality curves for deltamethrin were 62.55 and 123.96 h, respectively. These values were much higher for permethrin where KT_50 was 201.10 h and the KT_90 was beyond the detectable range. Results were compared with previous values reported for the same population in 2002. Resistance to propoxur has increased significantly from 11 to 51% with about a 20-fold increase in the number of individuals with elevated esterase mechanism. No significant change has occurred in malathion and DDT resistance, in GST and monooxygenase activities, and in AChE sensitivity for the past 14 years. Six kdr associated mutations (Y/L995H, V1010L, I1011F, L1014F, V1016E, L1017F/S) and a non- kdr associated mutation (A1007S mutation) were found from the α-region of the VGSC gene. Out of the kdr type mutations, only L1014F has been reported previously form C. Hemipterus while the others have been reported from other insects. Conclusions The bed bug population has developed high resistance to propoxur with increased esterase activities. KT_50 for deltamethrin and permethrin has increased 125- and 20-fold, respectively, over the period 2002 to 2016. To the authors’ knowledge, this is the first time that the possible involvement of a kdr type mutation in developing pyrethroid resistance in C. Hemipterus has been shown in Sri Lanka.