Assessment of Conventional Insecticides against Common Bed Bugs Cimex Hemipterus (Hemiptera: Cimicidae) in Jeddah Province, Saudi Arabia

Bed bugs, Cimex hemipterus (Hemiptera: Cimicidae) are small insects that are considered public health pests and cause many health and economic problems. The efficacy of Organophosphorus insecticides (Safrotin and Actikill) and pyrethroids (Project and Cyper Safe) in controlling C. hemipterus adults and nymphs were investigated using contact and dipping methods. The WHO protocol was followed for insecticides application. The results of the current study showed that the project pesticide from the pyrethroids group gave the highest effectiveness against bed bugs, as the value of the concentration that killed 50% (LC50) of insects was of the adults (264.8, 337.5 ppm) when using dipping and contact methods, respectively. while the LC50 value when applying the two methods of the same insecticide against nymphs was 254.7 and 329.3ppm, respectively. However, Safrotin the more effective organophosphorus insecticide. The dipping method was more effective than the contact method for all insecticides, and the nymphs were more susceptible than the adults (LC50= 1502.6 and 1065.28ppm). The pesticides can be arranged in descending order according to their effect as follows: Project> Cyper Safe > Safrotin > Actikill. Our findings suggest that bed bugs in Jeddah Province may have developed resistance to common pesticides used in public health pest management programs. For this reason, this study recommends a periodic evaluation of the effectiveness of pesticides to be used during emergency pest outbreaks

Diatomaceous Earth for Arthropod Pest Control: Back to the Future

Nowadays, we are tackling various issues related to the overuse of synthetic insecticides. Growing concerns about biodiversity, animal and human welfare, and food security are pushing agriculture toward a more sustainable approach, and research is moving in this direction, looking for environmentally friendly alternatives to be adopted in Integrated Pest Management (IPM) protocols. In this regard, inert dusts, especially diatomaceous earths (DEs), hold a significant promise to prevent and control a wide range of arthropod pests. DEs are a type of naturally occurring soft siliceous sedimentary rock, consisting of the fossilized exoskeleton of unicellular algae, which are called diatoms. Mainly adopted for the control of stored product pests, DEs have found also their use against some household insects living in a dry environment, such as bed bugs, or insects of agricultural interest. In this article, we reported a comprehensive review of the use of DEs against different arthropod pest taxa, such as Acarina, Blattodea, Coleoptera, Diptera, Hemiptera, Hymenoptera, Ixodida, Lepidoptera, when applied either alone or in combination with other techniques. The mechanisms of action of DEs, their real-world applications, and challenges related to their adoption in IPM programs are critically reported.

Human skin triglycerides prevent bed bug (Cimex lectularius L.) arrestment

Bed bugs (Cimex lectularius) have proliferated globally and have become one of the most challenging pests to control indoors. They are nocturnal and use multiple sensory cues to detect and orient towards their human hosts. After feeding, usually on a sleeping human, they return to a shelter on or around the sleeping surface, but not directly on the host. We hypothesized that although human skin odors attract hungry bed bugs, human skin compounds may also prevent arrestment on hosts. We used arrestment assays to test human skin swabs, extracts from human skin swabs, and pure compounds identified from human skin swabs. When given a choice, bed bugs preferred to arrest on substrates not previously conditioned by humans. These responses were consistent among laboratory-reared and apartment-collected bed bugs. The compounds responsible for this behavior were found to be extractable in hexane, and bed bugs responded to such extracts in a dose-dependent manner. Bioassay-guided fractionation paired with thin-layer chromatography, GC–MS, and LC–MS analyses suggested that triglycerides (TAGs), common compounds found on human skin, were preventing arrestment on shelters. Bed bugs universally avoided sheltering in TAG-treated shelters, which was independent of the number of carbons or the number of double bonds in the TAG. These results provide strong evidence that the complex of human skin compounds serve as multifunctional semiochemicals for bed bugs, with some odorants attracting host-seeking stages, and others (TAGs and possibly other compounds) preventing bed bug arrestment. Host chemistry, environmental conditions and the physiological state of bed bugs likely influence the dual nature behavioral responses of bed bugs to human skin compounds.

Estranged companions: Bed bugs, biologies, and affective histories

In recent decades, bed bugs have swept across wealthy industrialized nations. After near extirpation in North America and Northern Europe, the return of these insects has led to a significant level of public anxiety and cultural notoriety. Here, we undertake an analysis of human-bed bug relations in order to both better understand this contemporary resurgence and critically examine the concept of “companion species.” We argue for conceiving of bed bugs as “estranged companions,” and foreground the need to understand contemporary encounters between humans and the insects through distinct histories that have been shaped by the opening and closing of spaces between classed and racialized bodies and that have been dependent upon the development and deployment of particular technologies such as Dichlorodiphenyltrichloroethane (DDT). Further, we argue that “estrangement” has wider conceptual purchase and contributes to a body of research that has countered a strain of scientism in theory that decenters “the human” by interrogating the relations between companion species, (bio)political interventions, and colonial histories. Estrangement contributes to this task by, first, foregrounding that relationships with all companion species are imbricated in situated histories and biopolitical regimes and, second, drawing attention to the differential ethico-political implications of these regimes.

De bedwants: a bad bug?

The bed bug: a bad bug? The common bed bug, Cimex lectularius, is a bloodsucking ectoparasite which attacks mammals and is on the rise since the beginning of the early 21st century. They are brown and flat. Skin lesions appear after the painless bite, often during the predawn hours. Small, purpuric macules develop into erythematous, indurated papules on exposed areas of skin of the face, neck and extremities, and resolve over the course of 2 weeks. Often, a linear or cluster configuration of 3 to 4 lesions (‘breakfast, lunch and dinner’) appears. Pruritic wheal reactions represent a type 1 hypersensitivity reaction elicited by the parasite’s saliva antigens. The clinical differential diagnosis is broad and may include other insect and arthropod bites and stings, scabies infestation, dermatitis herpetiformis, ecthyma, etc. There is no evidence that bed bugs are vectors and transmit human pathogens. They are responsible for considerable physical irritation and significant psychological distress. Very rarely, the patient could develop anemia or anaphylaxis. Control involves treating both the patient’s symptoms and the cause by the eradication of the infestation, a challenge that may require a professional exterminator for an integrated pest management strategy. “Good night, sleep tight, don’t let the bed bugs bite!”

Factors Contributing to Community None Acceptance for Indoor Residual Spraying (IRS) for Malaria prevention in Chipushi Area of Mpika, Zambia

Indoor residual spraying (IRS) is one of the primary vector control interventions for reducing and interrupting malaria transmission. In recent years, however, it has received relatively little attention. Just like it is the case in the 17 villages of the Chipushi area of Mpika district in Muchinga province, Zambia. In community work, among the things that attracted my attention are the non-acceptance and perceived negative attitudes towards acceptance for indoor residual spraying. The purpose of this study was to analyze and establish the factors that contribute to none acceptance for Indoor Residual Spraying (IRS) in the Chipushi area of Mpika, Zambia. None acceptance, in this case, refers to a widespread negative response to having indoor residual spraying performed in people’s homes at the community level. Simple random sampling was used to come up with the study population. And after executing the study through the questionnaire and semi-structured interviews on the 97 respondents, findings revealed that 12 (12.4%) respondents believed that chemicals used in IRS increase mosquitoes and bed bugs instead of controlling them. Other 22 (22.7%) never believed IRS could reduce the incidence of malaria. 18 (18.6%) respondents avoided being in-convenience by the spray operators and health personnel. 10 (10.3%) respondents don’t want to be seen how wrecked their houses are or fear of being embarrassed due to lack of sanity in their homes. Similarly, 17 (17.5%) respondents believed that by the culture, they could not allow strangers to expose their privacy in their homes. Surprisingly 26 (26.8%) respondents never just wanted to participate in spray operations. Keywords: Community, Households, Indoor Residual Spraying, Malaria elimination, Prevention.

High levels of pyrethroid resistance and super-kdr mutations in the populations of tropical bed bug, Cimex hemipterus, in Iran

Background The tropical bed bug, Cimex hemipterus, is an important ectoparasite causing various health problems. This species is mainly confined to tropical regions; however, insecticide resistance, global warming, and globalization have changed its distribution map. Molecular information on pyrethroid resistance, which is essential for the development of control programs, is unknown for C. hemipterus in expanded areas. The present study was designed to determine the permethrin resistance status, characterize the pyrethroid receptor sites in voltage-gated sodium channel (vgsc) gene, and identify the resistance-related mutations in the populations of tropical bed bug in Iran. Methods Live bed bugs were collected, and adults of C. hemipterus were selected for bioassay and molecular surveys. Bioassay was performed by tarsal contact with permethrin 0.75% in mixed-sex of samples. Conventional and quantitative TaqMan and SYBR Green real-time PCR assays were conducted to characterize the vgsc gene and genotypes of studied populations. Results In the bioassay tests, the mortality rates were in the range of 30.7–38.7% and 56.2–77.4% in 24 and 48 h, respectively. The knockdown rates of studied populations were in the range of 32.2–46.6% and 61.5–83.8% in the first and second days, respectively. The KT50 and KT90 values in the Cimex lectularius Kh1 strain were presented as 5.39 and 15.55 h, respectively. These values in the selected populations of C. hemipterus varied from 27.9 to 29.5 and from 82.8 to 104.4 h, respectively. Knockdown time ratios (KR50 and KR90) in these populations varied from 5.17 to 6.17-fold compared with those of the C. lectularius Kh1 strain. Fragments of vgsc gene with 355 bp and 812 bp were amplified. Analysis of sequences revealed the A468T substitution, kdr-associated D953G, and super-kdr M918I and L1014F mutations in all populations. Conclusions The specific/sensitive, safe, and rapid diagnostic assays developed in this study are recommended for detection of kdr/super-kdr mutations and frequency of mutant alleles. The presence of super-kdr mutations and high resistance to permethrin in all the populations necessitate the reconsideration of control approaches against C. hemipterus. Graphical Abstract