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Stephen L. Doggett - One of the best experts on this subject based on the ideXlab platform.
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Binucleation of male accessory gland cells in the common bed bug Cimex lectularius.
Scientific reports, 2019Co-Authors: Koji Takeda, Stephen L. Doggett, Jun Yamauchi, Aoi Miki, Dae-yun Kim, Xin-yeng Leong, Chow-yang Lee, Takashi Adachi-yamadaAbstract:The insect male accessory gland (MAG) is an internal reproductive organ responsible for the synthesis and secretion of seminal fluid components, which play a pivotal role in the male reproductive strategy. In many species of insects, the effective ejaculation of the MAG products is essential for male reproduction. For this purpose, the fruit fly Drosophila has evolved binucleation in the MAG cells, which causes high plasticity of the glandular epithelium, leading to an increase in the volume of seminal fluid that is ejaculated. However, such a binucleation strategy has only been sporadically observed in Dipteran insects, including fruit flies. Here, we report the discovery of binucleation in the MAG of the common bed bug, Cimex lectularius, which belongs to hemimetabolous Hemiptera phylogenetically distant from holometabolous Diptera. In Cimex, the cell morphology and timing of synchrony during binucleation are quite different from those of Drosophila. Additionally, in Drosophila, the position of the two nuclei in the adult stage changes as a result of the mating history or the nutrient conditions; however, it remains stable in Cimex. These differences suggest that binucleation in the Cimex MAG plays a unique role in the male reproductive system that is distinct from that of Drosophila.
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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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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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Systemic and erythrodermic reactions following repeated exposure to bites from the Common bed bug Cimex lectularius (Hemiptera: Cimicidae)
Austral Entomology, 2016Co-Authors: Rashi Minocha, Cameron E. Webb, Kai Dang, Changlu Wang, Pablo Fernandez-penas, Stephen L. DoggettAbstract:Bed bugs (Cimex spp.) have undergone a global resurgence over the last 15–20 years. They readily bite humans, producing a range of cutaneous reactions. This article documents systemic reactions in two patients following repeated bites from the common bed bug, Cimex lectularius. Both patients had previously fed bed bugs on themselves without any serious complication, however upon feeding a new batch of the insects subsequently developed systemic urticarial reactions. Patient 1 fed 40–50 bed bugs on himself and after 8 min, he developed itch, swelling of the face, lethargy, profuse sweating and widespread wheals on the torso and limbs. The reaction disappeared in 5 h after treatment with systemic prednisone and antihistamines. Patient 2 developed a similar reaction after feeding five to six bed bugs on himself. In this case, the patient also developed chest tightness and breathing difficulties. Following a similar treatment, symptoms disappeared in 4 h. In light of the increasing exposure of this insect to the general public, systemic reactions in patients may present more commonly to the medical practitioner.
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simple rapid and cost effective technique for the detection of pyrethroid resistance in bed bugs Cimex spp hemiptera cimicidae
Australian Journal of Entomology, 2015Co-Authors: Kai Dang, David G. Lilly, Stephen L. DoggettAbstract:A ready to use d-allethrin impregnated mat (‘Mortein Odourless Mozzie Zapper’, Reckitt Benckiser) was used to detect pyrethroid resistance in bed bugs, Cimex spp. Bed bugs of different species, stages and strains were confined on the mat and knockdown measured over 24 h. The insecticide-susceptible ‘Monheim’ strain of Cimex lectularius was significantly (P < 0.001) more sensitive than the insecticide-resistant ‘Sydney’ strain of C. lectularius and the ‘North Queensland’ strain of C. hemipterus. Based on the results, a protocol to rapidly diagnose pyrethroid resistance is suggested whereby, unless 100% of 10 bed bugs (irrespective of the life stage) are knocked down after 1 h exposure to the d-allethrin impregnated mat at room temperature of 23 ± 1°C, the population can be considered resistant. This protocol was validated using six Australian field-collected strains of C. lectularius, which were known to possess ‘kdr’-type resistance mechanisms, of which there was no mortality at 1 h exposure. Thus, the protocol developed in this study can be used to monitor pyrethroid resistance in bed bug populations and should assist pest managers in determining the most appropriate control strategies for managing bed bug infestations.
José M. C. Ribeiro - One of the best experts on this subject based on the ideXlab platform.
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Insight into the Sialome of the Bed Bug, Cimex lectularius
Journal of proteome research, 2010Co-Authors: Ivo M. B. Francischetti, Jesus G. Valenzuela, Eric Calvo, John F. Andersen, Van My Pham, Amanda J. Favreau, Kent D. Barbian, Alvaro Romero, José M. C. RibeiroAbstract:The evolution of insects to a blood diet leads to the development of a saliva that antagonizes their hosts' hemostasis and inflammation. Hemostasis and inflammation are redundant processes, and thus a complex salivary potion comprised of dozens or near one hundred different polypeptides is commonly found by transcriptome or proteome analysis of these organisms. Several insect orders or families evolved independently to hematophagy creating unique salivary potions in the form of novel pharmacological use of endogenous substances, and in the form of unique proteins not matching other known proteins, these probably arriving by fast evolution of salivary proteins as they evade their hosts' immune response. In this work we present a preliminary description of the sialome (from the Greek Sialo = saliva) of the common bed bug Cimex lectularius, the first such work from a member of the Cimicidae family. This manuscript is a guide for the supplemental database files http://exon.niaid.nih.gov/transcriptome/C_lectularius/S1/Cimex-S1.zip and http://exon.niaid.nih.gov/transcriptome/C_lectularius/S2/Cimex-S2.xls
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Apyrase and anti-platelet activities from the salivary glands of the bed bug Cimex lectularius
Insect Biochemistry and Molecular Biology, 1996Co-Authors: Jesus G. Valenzuela, Ouatfa M. Chuffe, José M. C. RibeiroAbstract:Abstract Apyrase activity was detected in the salivary gland of Cimex lectularius . Kinetic, HPLC chromatography, isoelectric focusing gel electrophoresis and thermal sensitivity assays indicated that the enzymatic activity is the result of a true apyrase and not the result of independent or combined different enzyme activities. The apyrase activity was dependent on calcium and not on magnesium, manganese or zinc, and was inhibited in the presence of EDTA. The pH optimum for both, ATPase and ADPase activities was 8.5. A high specific activity of Cimex salivary apyrase for hydrolysis of both ADP and ATP was found. Cimex salivary gland apyrase activity decreased by 43 percent right after insects fed on blood as compared with insects before feeding. The apparent molecular mass of apyrase activity as determined by HPLC molecular sieving chromatography was 79 600 daltons. Additionally, a peak showing apyrase activity was detected with a molecular mass of 21 000. However, the small molecular mass activity shifted to a high molecular mass activity when the salivary gland homogenate was prepared in more alkaline buffer and frozen, thus suggesting that the high molecular weight form of Cimex apyrase may result from aggregation of active small units. The saliva of Cimex lectularius inhibited platelet aggregation induced by ADP; one salivary gland pair was sufficient to completely inhibit the aggregation of 0.1 ml of citrated platelet rich plasma induced by 5 μM ADP. The inhibitor was shown to be a component different than nitric oxide. Altogether the data suggest that Cimex salivary apyrase can act to prevent an important step on hemostasis, platelet aggregation, and thus play an important role during the insect feeding to overcome the vertebrate host hemostatic defense mechanism.
Richard C. Russell - One of the best experts on this subject based on the ideXlab platform.
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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.
David G. Lilly - One of the best experts on this subject based on the ideXlab platform.
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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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simple rapid and cost effective technique for the detection of pyrethroid resistance in bed bugs Cimex spp hemiptera cimicidae
Australian Journal of Entomology, 2015Co-Authors: Kai Dang, David G. Lilly, Stephen L. DoggettAbstract:A ready to use d-allethrin impregnated mat (‘Mortein Odourless Mozzie Zapper’, Reckitt Benckiser) was used to detect pyrethroid resistance in bed bugs, Cimex spp. Bed bugs of different species, stages and strains were confined on the mat and knockdown measured over 24 h. The insecticide-susceptible ‘Monheim’ strain of Cimex lectularius was significantly (P < 0.001) more sensitive than the insecticide-resistant ‘Sydney’ strain of C. lectularius and the ‘North Queensland’ strain of C. hemipterus. Based on the results, a protocol to rapidly diagnose pyrethroid resistance is suggested whereby, unless 100% of 10 bed bugs (irrespective of the life stage) are knocked down after 1 h exposure to the d-allethrin impregnated mat at room temperature of 23 ± 1°C, the population can be considered resistant. This protocol was validated using six Australian field-collected strains of C. lectularius, which were known to possess ‘kdr’-type resistance mechanisms, of which there was no mortality at 1 h exposure. Thus, the protocol developed in this study can be used to monitor pyrethroid resistance in bed bug populations and should assist pest managers in determining the most appropriate control strategies for managing bed bug infestations.
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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, Chow-yang Lee, David G. Lilly, 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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Simple, rapid and cost‐effective technique for the detection of pyrethroid resistance in bed bugs, Cimex spp. (Hemiptera: Cimicidae)
Australian Journal of Entomology, 2014Co-Authors: Kai Dang, David G. Lilly, Wenjun Bu, Stephen L. DoggettAbstract:A ready to use d-allethrin impregnated mat (‘Mortein Odourless Mozzie Zapper’, Reckitt Benckiser) was used to detect pyrethroid resistance in bed bugs, Cimex spp. Bed bugs of different species, stages and strains were confined on the mat and knockdown measured over 24 h. The insecticide-susceptible ‘Monheim’ strain of Cimex lectularius was significantly (P
Kai Dang - One of the best experts on this subject based on the ideXlab platform.
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Systemic and erythrodermic reactions following repeated exposure to bites from the Common bed bug Cimex lectularius (Hemiptera: Cimicidae)
Austral Entomology, 2016Co-Authors: Rashi Minocha, Cameron E. Webb, Kai Dang, Changlu Wang, Pablo Fernandez-penas, Stephen L. DoggettAbstract:Bed bugs (Cimex spp.) have undergone a global resurgence over the last 15–20 years. They readily bite humans, producing a range of cutaneous reactions. This article documents systemic reactions in two patients following repeated bites from the common bed bug, Cimex lectularius. Both patients had previously fed bed bugs on themselves without any serious complication, however upon feeding a new batch of the insects subsequently developed systemic urticarial reactions. Patient 1 fed 40–50 bed bugs on himself and after 8 min, he developed itch, swelling of the face, lethargy, profuse sweating and widespread wheals on the torso and limbs. The reaction disappeared in 5 h after treatment with systemic prednisone and antihistamines. Patient 2 developed a similar reaction after feeding five to six bed bugs on himself. In this case, the patient also developed chest tightness and breathing difficulties. Following a similar treatment, symptoms disappeared in 4 h. In light of the increasing exposure of this insect to the general public, systemic reactions in patients may present more commonly to the medical practitioner.
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simple rapid and cost effective technique for the detection of pyrethroid resistance in bed bugs Cimex spp hemiptera cimicidae
Australian Journal of Entomology, 2015Co-Authors: Kai Dang, David G. Lilly, Stephen L. DoggettAbstract:A ready to use d-allethrin impregnated mat (‘Mortein Odourless Mozzie Zapper’, Reckitt Benckiser) was used to detect pyrethroid resistance in bed bugs, Cimex spp. Bed bugs of different species, stages and strains were confined on the mat and knockdown measured over 24 h. The insecticide-susceptible ‘Monheim’ strain of Cimex lectularius was significantly (P < 0.001) more sensitive than the insecticide-resistant ‘Sydney’ strain of C. lectularius and the ‘North Queensland’ strain of C. hemipterus. Based on the results, a protocol to rapidly diagnose pyrethroid resistance is suggested whereby, unless 100% of 10 bed bugs (irrespective of the life stage) are knocked down after 1 h exposure to the d-allethrin impregnated mat at room temperature of 23 ± 1°C, the population can be considered resistant. This protocol was validated using six Australian field-collected strains of C. lectularius, which were known to possess ‘kdr’-type resistance mechanisms, of which there was no mortality at 1 h exposure. Thus, the protocol developed in this study can be used to monitor pyrethroid resistance in bed bug populations and should assist pest managers in determining the most appropriate control strategies for managing bed bug infestations.
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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, Chow-yang Lee, David G. Lilly, 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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Simple, rapid and cost‐effective technique for the detection of pyrethroid resistance in bed bugs, Cimex spp. (Hemiptera: Cimicidae)
Australian Journal of Entomology, 2014Co-Authors: Kai Dang, David G. Lilly, Wenjun Bu, Stephen L. DoggettAbstract:A ready to use d-allethrin impregnated mat (‘Mortein Odourless Mozzie Zapper’, Reckitt Benckiser) was used to detect pyrethroid resistance in bed bugs, Cimex spp. Bed bugs of different species, stages and strains were confined on the mat and knockdown measured over 24 h. The insecticide-susceptible ‘Monheim’ strain of Cimex lectularius was significantly (P