Infestation of cockroaches (Insecta: Blattaria) in the human dwelling environments: A systematic review and meta-analysis

Insecticidal Activity of Essential Oils and Their Synergistic Effect on Improving the Efficacy of β-Cypermethrin against Blattella germanica

We screened the contact activity of 32 commercial essential oils (EOs) and their synergistic effect with β-cypermethrin against Blattella germanica. Results showed that the most effective EOs against B. germanica were from Illicium verum, Syzygium aromaticum, and Cinnamomum camphora, with LD50 values of less than 500 μg/insect. The most potent synergistic effects of β-cypermethrin on B. germanica were from Dysphania ambrosioides and Mentha canadensis. Both oils have a co-toxic factor of 133.33. The results of the major compound testing of the EOs showed that trans-anisaldehyde and thymol have the best insecticidal activity against B. germanica, with LD50 values of 141.30 and 138.61 μg/insect, respectively. The compounds with the best synergistic effect on β-cypermethrin were γ-terpinene and linalool at a concentration of 0.5%. The co-toxic factors for γ-terpinene and linalool were 150 and 133.33, respectively, which were similar to the synergistic effect observed with 2% piperonyl butoxide.

Evaluation of the effectiveness of two Iranian su-strains of Metarhizium anisopliae (ascomycota: hypocreales) on the mortality rate of American cockroach

The cockroach is one of the most important disease vectors in world. Entomopathogenic fungi, as three concentrations of spores were taken 1.1 × 105, 1.1 × 107, and 1.1 × 109 conidia/mL from two isolates of Nour and Saravan-Iranian. In this study, the immersion method caused about 13% mortality only in isolation (1 × 109 conidia/mL) of Saravan isolates. Inoculation of isolates below the pronotum did not significantly differ the mortality rate between the two genera (P = 0.8), compared to the pathogenicity of three isolates of M. anisopliae (1.1 × 105, 1.1 × 107, and 1.1 × 109 conidia/mL). In total, Saravan and Nour isolates were 66%, 73%, and 93%, respectively, indicating a significant difference (P < 0.001). Mortality of male and female cockroaches with Saravan isolates respectively occurred 3 and 4 days after inoculation (LT50 = 4.3d), while for Nour isolates, in both sexes, mortality was observed within four days after the test (LT50 = 5.5d). Considering the results M. anisopliae can be one benefit methods for control American cockroach in the future.                       .

Intestinal pathogens detected in cockroach species within different food-related environment in Pudong, China

Cockroaches are considered mechanical transmitters of infectious diseases, posing a threat to human health. This study assessed the potential of cockroaches in food-related environments to mechanically transmit intestinal pathogens. Cockroaches captured with traps were placed together into a low temperature refrigerator at - 80° for 2 h. Standard taxonomic keys and Fluorescent quantitative PCR techniques were applied for species identification and digestive tract etiological examination. A total of 360 cockroach traps were placed, with a positive rate of 20.8%, and 266 cockroaches were captured. In general, compared with other places and areas, the degree of infestation of cockroaches was more serious in catering places and kitchens. Blattella germanica were most found in catering places (40.2%), followed by Periplaneta fuliginosa in schools (22.2%). According to the life stage, among the 128 cockroach samples, 23 were positive for nymphs and 13 were positive for adults. There were statistically significant differences in the intestinal pathogen detection rates between nymphs and adults (P < 0.05). A total of eight intestinal pathogens were detected, and enterovirus infections were the main ones, with sapovirus being the most detected in Blattella germanica or nymph. Shiga toxin-producing Escherichia coli (STEC) was the most frequently isolated bacterium. Blastocystis hominis had the highest isolation rate. In contrast, 12 diarrhoeal disease pathogens were isolated, and the viruses and bacteria with the highest frequencies were norovirus and E. coli, respectively; no parasites were found. Blattella germanica and Periplaneta fuliginosa in food-related environments can act as potential vectors for the spread of intestinal pathogens and may pose a significant threat to public health.

Differential development and survival of Blattella asahinai and Blattella germanica (Blattodea: Ectobiidae) at six constant temperatures

The Asian cockroach, Blattella asahinai Mizukubo, is a peridomestic nuisance pest in the southeastern United States. Blattella asahinai is the closest relative to Blattella germanica (L.), the German cockroach, one of the most prolific and widespread domestic pests. Because these two species live in different habitats, they are expected to have differential development patterns reflecting environmental adaptations. Development of B. asahinai and B. germanica cockroach nymphs were observed at six constant temperatures ranging from 10 to 35 °C. At 10 °C and 15 °C, all nymphs died in the first instar, but B. germanica nymphs survived longer (10 °C: 12.9 d; 15 °C: 42.9 d) than B. asahinai nymphs (10 °C 8.2 d; 15 °C 18.4 d) at both temperatures. At 20 °C, 25 °C, and 30 °C, B. asahinai consistently had more instars and longer stadia than B. germanica. At 35 °C, only B. germanica was able to complete nymphal development; cannibalism among B. asahinai nymphs during molting was often observed at this temperature. The results for B. asahinai corroborated previously estimated growth patterns. The lower nymphal development threshold was 14.1 °C for B. germanica and 13.7 °C for B. asahinai. Comparing the development of B. germanica directly with its closest relative reveals specific physiological adaptations that B. germanica has developed for the indoor biome.

Effects of copper and zinc oxide nanoparticles on German cockroach development, indoxacarb resistance, and bacterial load

BACKGROUND

The German cockroach, Blattella germanica, is a ubiquitous and medically significant urban pest. The ongoing development of insecticide resistance in global populations of B. germanica has complicated control efforts and created a need for improved tools. We previously reported that disruption of the gut microbiota by oral administration of the antimicrobial doxycycline reduced resistance in an indoxacarb resistant field strain and also delayed nymphal development and reduced adult fecundity. However, the application of doxycycline for cockroach control in the field is impractical. Here, we sought to determine whether two metal nanoparticles with known antimicrobial properties, copper (Cu) and zinc oxide (ZnO), have similar effects to doxycycline on the physiology of B. germanica and could provide more practical alternatives for control.

RESULTS

We found that dietary exposure to 0.1% Cu nanoparticles, but not ZnO, significantly delays the development of nymphs into adults. However, neither of the nanoparticles altered the fecundity of females, and ZnO surprisingly increased resistance to indoxacarb in a resistant field strain, in contrast to doxycycline. Semi-quantitative polymerase chain reaction (qPCR) further revealed that prolonged dietary exposure (14 days) to Cu or ZnO nanoparticles at the low concentration readily consumed by cockroaches (0.1%) does not reduce the load of the bacterial microbiota, suggesting alternative mechanisms behind their observed effects.

CONCLUSIONS

Together, our results indicate that ingestion of Cu nanoparticles can impact German cockroach development through an undetermined mechanism that does not involve reducing the overall load of the bacterial microbiota. Therefore, Cu may have some applications in cockroach control as a result of this activity but antagonistic effects on insecticide resistance should be considered when evaluating the potential of nanoparticles for cockroach control. © 2023 Society of Chemical Industry.

Monitoring of hard tick parasitism in domestic ruminants: A scale evidence for policymakers

Domestic ruminants such as camels, cattle, goats, and sheep represent a substantial part of the global world economy. Hard ticks are well-known as obligatory bloodsucking ectoparasites of domestic ruminants. Policymakers need to get results that show the global distribution of tick genera and species, their parasitic levels, and their roles as disease vectors in camels, cattle, goats, and sheep. Iran is endemic to a broad range of hard tick-borne diseases. A study that reviews the tick genera and species, life stage, seasonal and attachment site parasitism levels, the global mean ranks of tick species parasitism rates and records, and their distribution in target animals would be of particular importance. Accordingly, this review aims to summarize the above objectives. After evaluating the identified articles, 147 were selected to be part of the survey based on the study objectives. Globally, tick parasitism levels were 28.7, 29.9, 36.0 and 47.6% for goats, cattle, sheep, and camels, respectively. The tick parasitism trends have exhibited an increasing trend for camels and sheep over the years while remaining constant for cattle and goats, indicating that current tick control measures are not being properly followed. Ticks tend to parasitize females more than males because males are more resistant to certain pests than females. The distribution of tick genera and species, their parasitism levels, and their roles as disease vectors provided. This information addresses the needs of decision-makers to make decisions.

Impacts of Bioassay Type on Insecticide Resistance Assessment in the German Cockroach (Blattodea: Ectobiidae)

The German cockroach, Blattella germanica (L.), is one of the most critical urban pests globally due to the health risks it imposes on people, such as asthma. Insecticides are known to manage large cockroach population sizes, but the rapid rate at which they develop resistance is a continuing problem. Dealing with insecticide resistance can be expensive and time-consuming for both the consumer and the pest management professional (PMP) applying the treatment. Each cockroach population is unique because different strains have different insecticide susceptibilities, so resistance profiles must be considered. This study addressed the above issue in a controlled laboratory setting. Cockroach strains from Indianapolis, Indiana, Danville, Illinois, and Baltimore, Maryland, USA were used. Four insecticide active ingredients (AIs) most used by consumers and PMPs were selected for testing in vial bioassays to establish resistance profiles. Next, no-choice and choice feeding assays with four currently registered bait products were performed to assess the impacts of competing food and circadian rhythms on bait resistance levels. The results indicate that emamectin benzoate (Optigard) was the most effective AI in causing the highest mortality in all strains in vial and no-choice bioassays; whereas, the other AIs and products were more impacted by resistance. The results acquired from these studies can help develop rapid tests for use by PMPs based on the no-choice feeding assay while also adding more information supporting current resistance and cross-resistance evolution theories.

Diet Influences the Gut Microbial Diversity and Olfactory Preference of the German Cockroach Blattella germanica

The gut microbiota of insects has been proven to play a role in the host's nutrition and foraging. The German cockroach, Blattella germanica, is an important vector of various pathogens and causes severe allergic reactions in humans. Food bait is an effective and frequently used method of controlling this omnivorous insect. Thus, understanding the relationships among diet, gut microbiota, and olfactory preferences could be useful for optimizing this management strategy. In this study, B. germanica was exposed to different foods, i.e., high-fat diet, high-protein diet, high-starch diet, and dog food (as control). Then their gut microbial and olfactory responses were investigated. 16S rRNA gene sequencing confirmed that the gut microbiota significantly differed across the four treatments, especially in relation to bacteria associated with the metabolism and digestion of essential components. Behavioral tests and the antenna electrophysiological responses showed that insects had a greater preference for other types of diets compared with their long-term domesticated diet. Moreover, continuously providing a single-type diet could change almost all the OR genes' expression of B. germanica, especially BgORco, which was significantly repressed compared to control. These results indicate that diet can shape the gut microbiota diversity and drive the olfactory preference of B. germanica. The association between gut microbiota profiles and diets can be utilized in managing B. germanica according to their olfactory preference.

Melanin synthesis genes BgTH and BgDdc affect body color and cuticle permeability in Blattella germanica

Melanin is involved in cuticle pigmentation and sclerotization of insects, which is critical for maintaining structural integrity and functional completeness of insect cuticle. The 2 key enzymes of tyrosine hydroxylase (TH) and dopa decarboxylase (DDC) predicted in melanin biosynthesis are usually conserved in insects. However, it is unclear whether their function is related to epidermal permeability. In this study, we identified and cloned the gene sequences of BgTH and BgDdc from Blattella germanica, and revealed that they both showed a high expression at the molting, and BgTH was abundant in the head and integument while BgDdc was expressed highest in the fat body. Using RNA interference (RNAi), we found that knockdown of BgTH caused molting obstacles in some cockroaches, with the survivors showing pale color and softer integuments, while knockdown of BgDdc was viable and generated an abnormal light brown body color. Desiccation assay showed that the dsBgTH-injected adults died earlier than control groups under a dry atmosphere, but dsBgDdc-injected cockroaches did not. In contrast, when dsRNA-treated cockroaches were reared under a high humidity condition, almost no cockroaches died in all treatments. Furthermore, with eosin Y staining assay, we found that BgTH-RNAi resulted in a higher cuticular permeability, and BgDdc-RNAi also caused slight dye penetration. These results demonstrate that BgTH and BgDdc function in body pigmentation and affect the waterproofing ability of the cuticle, and the reduction of cuticular permeability may be achieved through cuticle melanization.

The different aspects of attractive toxic baits containing fipronil for control of the German cockroach (Blattella germanica)

The use of Attractive Toxic Baits (ATBs) is considered to be a low-risk practical method for controlling cockroaches. This study evaluates the attractiveness of a lab-made, fipronil-containing bait, and its effect on the food consumption and mortality of the German cockroach Blattella germanica, under field and laboratory conditions. Different developmental stages of the cockroach were used to determine their preferred carbohydrate/protein rich foods and examine the effectiveness of lab-made baits. The analysis of variance (ANOVA) with Tukey's Test was determined using SAS 9.1 and GraphPad Prism software programs. The significance level was considered at p<0.05. The most-consumed foods were carbohydrate-rich foods (biscuit and banana powder) and food consumption rate was highest in non-gravid females. The most attractive bait ingredients were 20% roasted peanut butter, 50% biscuit and 30% banana powder. The highest lethality was recorded from the baits containing 0.02% fipronil under laboratory conditions, while infested houses baited with the lab-made bait showed 76.5% and 100% decline, respectively, in cockroach numbers in the first- and fourth-week post-baiting. In conclusion, palatable foods with a pleasant odour, like biscuit powder, banana powder and peanut butter were the most effective ingredients for the ATBs. The ATBs impregnated with 0.02% fipronil provide a promising approach for control of the German cockroach. However, there is a need to evaluate the potentials of the lab-made baits, under laboratory and field conditions, in the control of other health-important cockroaches.

Detection of Voltage-Gated Sodium Channel (VGSC) Mutation in Deltamethrin-Resistant Blattella germanica L. from Indonesia

&lt;b&gt;Background and Objective:&lt;/b&gt; German cockroach (&lt;i&gt;Blattella germanica&lt;/i&gt; L.) is one of the most common residential pests in Indonesia. Controlling the population face obstacles due to insecticide resistance, especially to deltamethrin. This research investigated the resistance status and the possibility of a Voltage-Gated Sodium Channel (VGSC) knockdown resistance mutation (L1014F) in two field strains of German cockroaches collected from two cities in Indonesia (Bukittinggi, named RMKN-BKT and Bandung, named KRSA-BDG) with VCRU-WHO as the standard strain. &lt;b&gt;Materials and Methods:&lt;/b&gt; This study started with a bioassay test to determine the lethal dose of 50% (LD&lt;sub&gt;50&lt;/sub&gt;) for each strain and followed by a molecular test for mutation detection. &lt;b&gt;Results:&lt;/b&gt; The results showed that the RMKN-BKT and KRSA-BDG strains were highly resistant to deltamethrin with RR50 values of 80,090 times and 73,272 times, respectively. Only the RMKN-BKT strain was shown to carry L1014F kdr mutation which lead to an amino acid replacement from leucine (TTG) to phenylalanine (TTC). Two silent mutations were also found in both field strains at codons 983 (TGC/cysteine→TGT/cysteine) and 984 (GGG/ glycine→GGA/glycine) which were suggested as polymorphism phenomena. The absence of the L1014F mutation in the Bandung strain does not exclude the possibility of the presence of the VGSC mutation at other points. &lt;b&gt;Conclusion:&lt;/b&gt; It requires subsequent investigation in mutation detection at other points and the possible presence of other resistance mechanisms to get a precise solution in the population control. Bioinsecticides may stand as a breakthrough so that the strategy will no longer focus on insecticides.

SARS-CoV-2 Transmission by Arthropod Vectors: A Scoping Review

COVID-19 is a respiratory disease of worldwide importance as it has brought enormous health problems to the world's population. The best-known way of transmission of the virus is through aerosolization. However, research is needed to explore other transmission routes. Researchers hypothesized that arthropods could transmit SARs-CoV-2. This study is aimed at reviewing research on arthropods as possible reservoirs and/or vectors of SARS-CoV-2, the causative agent of COVID-19. Following PRISMA guidelines, we conducted a systematic review using several electronic databases/academic searches with the search terms "arthropods," "coronavirus," and "transmission." A total of 64 unique articles were identified, of which 58 were included in the review. The SARS-CoV-2 virus is tiny and invisible to the naked eye, and its presence in stools, droplets, and surfaces was detected. One doubt is whether insects can transmit the virus from one place to another. Thus, a healthy carrier of the COVID-19 virus can be at the root of the contamination of their community or their family through the transport of the virus by insects from the interior (flies, cockroaches, etc.) from their feces and food surfaces. Hygiene care within communities and families becomes a prime factor. Coronavirus infection is a significant public health problem around the world. The prevention and control of outbreaks remain very important, even with the production of new vaccines. The main option to achieve this is the proper management of the transmission of the virus. The registry of infected people is currently the basis for the transmission of COVID-19. However, questions about the possibility of infection from other sources and its prevention are not receiving adequate attention. Numerous studies have shown the possibility that SARS-COV-2 fragments could have a longer life than shed respiratory droplets. Also, this virus is larger than those of other coronavirus families.

Metarhizium anisopliae is a valuable grist for biocontrol in beta-cypermethrin-resistant Blattella germanica (L.)

BACKGROUND

The widespread use of chemical insecticides has resulted in the development of resistance in German cockroaches worldwide, and biopesticides based on entomopathogenic fungi as active ingredients have become a promising alternative strategy. Resistance can change many of the physiological and biochemical characteristics of insect pests, such as cuticle thickness, detoxification enzyme activity, and even intestinal flora composition. Thus, potential interactions between pathogenic fungi and insecticide resistance may lead to unpredictable changes in pest susceptibility to fungi.

RESULTS

Beta-cypermethrin-resistant German cockroaches were more susceptible to infection with the fungus Metarhizium anisopliae regardless of age and sex. Histopathological results showed that the infection of resistant strains (R) by M. anisopliae was visibly faster than that of susceptible strains (S). The gut microbiota of the S strain indicated a stronger ability to inhibit fungi in vitro. The abundance of Parabacteroides, Lachnoclostridium, and Tyzzerella_3 decreased significantly in the R strain, and most demonstrated the ability to regulate glucose and lipid metabolism, and antifungal infections. The expression levels of Akirin, BgTPS, and BgPo genes in the R strain were significantly lower than those in the S strain, while BgChi and CYP4G19 gene expression were significantly higher. The mortality of cockroaches infected with M. anisopliae decreased to varying degrees after RNA interference, reflecting the role of these genes in antifungal infection.

CONCLUSIONS

Results confirmed that insecticide resistance may enhance cockroach susceptibility to fungi by altering intestinal flora and gene expression. Fungal biopesticides have high utilization value in pest control and insecticide resistance management strategies. © 2021 Society of Chemical Industry.

Morphological and Molecular Identification of Emerged Lophomonas blattarum Infection in Mazandaran Province, Northern Iran: First Registry-Based Study

BACKGROUND

In the last decade, several cases of bronchopulmonary lophomoniasis (BPL) have been recorded. Little information is available about epidemiological aspects on Lophomonas infection among BPL patients. The present study was aimed to investigate the prevalence of Lophomonas spp. infection in patients who were referred to the Iranian National Registry Center for Lophomoniasis (INRCL), using morphological and molecular tests.

SUBJECTS AND METHODS

We examined patients enrolled in the INRCL from 2017 to 2019 at the Mazandaran University of Medical Sciences, northern Iran. All bronchoalveolar lavage fluid (BALF) and two nasal discharges of the patients were examined by both microscopic and small-subunit ribosomal RNA (SSU rRNA) PCR methods. To confirm the species of Lophomonas, two positive samples were sequenced.

RESULTS

In this study, 321 specimens (including 319 BALF and 2 nasal discharges) were microscopically examined. Lophomonas spp. was found in 45(14%) (n = 44 BAL; n = 1 nasal discharge). The mean age of infected patients was 54.9 ± 17.1 years. The following morphological characteristics were observed in both fresh and Papanicolaou-stained smears to identify Lophomonas spp. All microscopically positive specimens were confirmed with genus-specific PCR technique. The obtained sequences were deposited in Gen Bank under the accession numbers (MN243135-36). The BLAST analysis of our two sequences with the only available sequence in the Gen Bank of the Thailand strain of L. blattarum, showed identity of 99-100% and 98.51%, respectively.

CONCLUSION

To the best of our knowledge, this is the first registry-based study regarding lophomoniasis worldwide. According to our study, the conventional PCR test is an available and reliable tool for confirming the Lophomonas parasite in clinical samples. Moreover, the results confirmed that L. blattarum is circulating at least in our region.

First report of Lophomonas spp. in German cockroaches (Blattella germanica) trapped in hospitals, northern Iran

Cockroaches are considered to be important reservoirs for protozoan and helminth parasites,particularly an emerging Lophomonas spp., protozoan parasite. German cockroaches, Blattella germanica (B. germanica), are domestic pest distributed worldwide. However, little information is available regarding the burden of Lophomonas spp. infestation among domestic cockroach population worldwide. The present study investigated parasitic agents, emphasizing Lophomonas spp. infestation among B. germanica in northern Iran. During spring and summer 2018, a total of 496 adults B. germanica (265 males and 231 females) were trapped by hand and glass traps from the teaching hospitals in Mazandaran, Sari, northern Iran. All cockroaches were identified using taxonomic keys. Each cockroaches was anesthetized with chloroform and the alimentary tract removed. Each section was smeared onto a glass slide. All the smears were examined under light microscopy to determine the presence of the parasites. Ten genera of parasites were identified from the trapped B. germanica; overall, 233 (47%) were found to be positive for helminths (n = 135) and protozoa (n = 98). The helminths included Aspiculuris tetraptera egg (67/233, 28.7%), Oxiuros sp. (39/233; 16.7%), Dentostomella translucida (17/233; 7.3%), and nematodes Ova (12/233; 5.2%). The protozoan parasites identified Gregarina sp. (61/233; 26.2%), Entamoeba sp. (19/233; 8.2%), Blastocystis sp. (5/233; 2.1%), Lophomonas (4/233; 1.7%), Nyctotherus sp. (4/233; 1.7%), unclassified flagella (5/233; 2.1%). Lophomonas spp. was detected within the gut of B. germanica, for the first time, in Iran. It has previously been identified in the gut of cockroaches a long time ago, however, this is the first attempt to detect Lophomonas in cockroaches housing in hospitals. Thereby, it possibly presenting pose a serious respiratory infection risk for patients and health care personnel.

Oral toxicity of various Stemona collinsiae crude extracts against nymph and adult stages of American cockroach, Periplaneta americana (Dictyoptera: Blattodea)

Stemona collinsiae exhibits insecticidal resistance against various pests and insect vectors. However, insecticidal activity of S. collinsiae roots has not been tested for some insect vectors, including the American cockroach, Periplaneta americana. The synanthropic insect P. americana is a reservoir of pathogenic and non-pathogenic microorganisms and a cause of infectious diseases and cockroach allergy. This important vector transmits microorganisms to animals and humans to cause vector-borne diseases. This research involved detection of the nymphicidal and adulticidal activities of S. collinsiae root extracts against P. americana through oral administration. The effects of hexane, dichloromethane, ethanol, and water crude extracts were tested on final instar nymphs and adult P. americana. After P. americana ingested bait containing hexane and dichloromethane crude extracts, signs of toxicity occurred, such as hind leg shaking, whole-body tremor, immobility, abdomen swelling, and death. At 48 h, the nymphs and adult P. americana that ingested dichloromethane crude extract-containing bait showed corrected mortality of 65%-100% and 20%-100%, respectively. Whereas none of the nymphs and adult P. americana that ingested the water crude extract-containing bait died (0% corrected mortality). When we dissected alimentary canals of the dead P. americana that had ingested dichloromethane and hexane crude extract-containing baits, the foreguts were found to be swollen. TLC analysis showed the dichloromethane and hexane crude extracts contained the alkaloid didehydrostemofoline and unknown fluorescent substances. Phytochemicals from crude extracts were detected in extracts of dissected alimentary canals using thin-layer chromatography, and didehydrostemofoline alkaloid and unknown fluorescent substances were found in cockroaches that ingested dichloromethane- and hexane-containing baits. The cause of death of P. americana may be attributed to alkaloids and synergistic effects of other substances in S. collinsiae root extract. Mechanisms of action might include several pathways involved in nervous system function. Thus, dichloromethane and hexane crude extracts can be developed as alternative active ingredients in a natural insecticide for cockroach control.

Detailed Infestation Spectrums About Biological Stages of Hard Ticks (Acari: Ixodida: Ixodidae) in Humans: A Systematic Review and Meta-Analysis

PURPOSE

A comprehensive systematic meta-analysis review which deals with the degrees and trends of human infestation by biological stages of ticks, the degrees and trends of human infestation by biological stages of ticks in rural and urban areas, the infestation scale of tick attachment sites in body parts of humans, and the degrees of tick infestation in human age groups is critical. Therefore, this systematic meta-analysis review summarizes the above-detailed human infestation spectrums about biological stages of hard ticks.

METHODS

After a preliminary review from 605 papers representing areas of the study objectives, 96 were selected for detailed human infestation spectrums of biological stages of hard ticks.

RESULTS

In general, the results suggest that the adult ticks, and mostly females attack humans more than larval and nymphalid ones, and adult males, respectively. Unlike the trends of human infestation by larval and nymphalid stages of ticks, and the adult, male and female ticks which exhibited approximately a sharply decreasing trend, the global trend of human infestation by hard ticks exhibited approximately a sharply increasing trend over time. Ticks attack humans more in rural area than urban area. Also, the trends of human tick infestation in rural and urban areas exhibit, respectively, a sharp increase and decrease trends over time.

CONCLUSIONS

The majority of ticks mostly attach to human body trunk and extremity than head and neck, and genital area. Ticks attack human age groups of 0-9, 20-39, and 40-59 years more than those aged between 10 and 19 or older than 60 years.

Component-Resolved Diagnosis of American Cockroach (Periplaneta americana) Allergy in Patients From Different Geographical Areas

Background: Manifestation of respiratory allergy to American cockroach (Periplaneta americana) is prominent in the subtropical and tropical areas. However, co-existing perennial indoor inhalant allergies frequently compromise clinical diagnosis of cockroach allergy, and the analysis of sensitization pattern is limited by the lack of Periplaneta allergens widely available for component-resolved diagnostics (CRD).

Objective: To evaluate a collection of previously described recombinant Periplaneta allergens for CRD in cockroach allergy.

Methods: A panel of nine recombinant Periplaneta allergens (Per a 1–5, 7–10) was generated, purified, and subjected to physicochemical characterization by applying circular dichroism (CD) spectroscopy, dynamic light scattering (DLS), amino acid (AA) analysis, and mass spectrometry (MS). Patients (n = 117) from India, Korea, Venezuela, and Iran, reporting perennial respiratory indoor allergies with IgE sensitization to cockroach (P. americana and/or Blattella germanica), were included. The sensitization profile was monitored by the experimental ImmunoCAP testing.

Results: ImmunoCAP testing confirmed IgE sensitization to Periplaneta and/or Blattella extract in 98 of 117 patients (r = 0.95). Five out of 117 patients were sensitized to only one of the two cockroach species. Within the whole study group, the prevalence of sensitization to individual allergens varied from 4% (Per a 2) to 50% (Per a 9), with the highest IgE values to Per a 9. Patients from four countries displayed different sensitization profiles at which Per a 3 and Per a 9 were identified as major allergens in India and Korea. Periplaneta-derived lipocalin and myosin light chain were characterized as new minor allergens, designated as Per a 4 and Per a 8. Periplaneta extract showed higher diagnostic sensitivity than all individual components combined, suggesting the existence of allergens yet to be discovered.

Conclusion: Utilization of a panel of purified Periplaneta allergens revealed highly heterogeneous sensitization patterns and allowed the classification of lipocalin and myosin light chain from Periplaneta as new minor allergens.

New insights about human tick infestation features: a systematic review and meta-analysis

There are many studies that provide information regarding ticks infesting humans. However, there is no a meta-analysis about the global ranks of tick infestation rates and records, global monthly tick bites and annually and periodically trends of tick infestation rates, and the global tick infestation rates among years, mounts, regions, and countries. The study provides new insights about the above objectives in a global context and therefore performed. After a preliminary review of the 610 papers representing objective areas, 241 were selected for detailed meta-analysis. In general, the global ranks of tick species were, respectively, between 0.01-85.4% and 1-53 for human infestation rates and records. Twenty-six and sixteen tick species have more than 10% and 10 records of human tick infestation rates and records, respectively. It seems these tick species tend to be more blood-feeding on humans and as a result can be more dangerous to humans. The outcome of study demonstrated that there is no difference between seasonal human tick infestation patterns in the northern and southern hemispheres. The most global monthly mean tick bites in humans were observed in June then followed in July, August, May, and September. The global annually and periodically trends of tick infestation rates in humans exhibited decreasing trends over the past decades suggesting the preventive measure to prohibit human tick infestation have been successful. It seems that the ranks of tick infestation rates and records in humans may be as two indexes to illustrate the degree of importance of tick infesting humans.

Insects, Rodents, and Pets as Reservoirs, Vectors, and Sentinels of Antimicrobial Resistance

This paper reviews the occurrence of antimicrobial resistance (AMR) in insects, rodents, and pets. Insects (e.g., houseflies, cockroaches), rodents (rats, mice), and pets (dogs, cats) act as reservoirs of AMR for first-line and last-resort antimicrobial agents. AMR proliferates in insects, rodents, and pets, and their skin and gut systems. Subsequently, insects, rodents, and pets act as vectors that disseminate AMR to humans via direct contact, human food contamination, and horizontal gene transfer. Thus, insects, rodents, and pets might act as sentinels or bioindicators of AMR. Human health risks are discussed, including those unique to low-income countries. Current evidence on human health risks is largely inferential and based on qualitative data, but comprehensive statistics based on quantitative microbial risk assessment (QMRA) are still lacking. Hence, tracing human health risks of AMR to insects, rodents, and pets, remains a challenge. To safeguard human health, mitigation measures are proposed, based on the one-health approach. Future research should include human health risk analysis using QMRA, and the application of in-silico techniques, genomics, network analysis, and ’big data’ analytical tools to understand the role of household insects, rodents, and pets in the persistence, circulation, and health risks of AMR.

Protozoan Cysts in Faecal Pellets of German Cockroaches (Blattella germanica), with Particular Emphasis on Lophomonas blattarum

Purpose

The aim of this study was to investigate protozoan cysts and oocyts in the faecal pellets of the German cockroach (Blattella germanica), with emphasis on the prevalence of Lophomonas blattarum.

Methods

Thirty adult Blattella germanica (12 males; 18 females) were trapped near Madrid, Spain. Expelled faecal pellets were collected in the laboratory over 5 days in two plastic containers. Protozoan cysts from one container were weighted and those in the other used for morphologically identification.

Results

Protozoan cysts/oocysts per gram of faecal pellet were: Nyctotherus sp. (0.0019/g), Entamoeba (0.0007/g), Balantidium coli (0.0001/g), Lophomonas blattarum (0.00038/g). Observation of 189 protozoan cysts/oocysts indicated the following prevalence: Nyctotherus sp. 65 (34.4%); Gregarina spp. 34 (18%); Entamoeba sp. 24 (12.7%); Cryptosporidium sp. 17 (9%); Coccidia 16 (8.4%); Lophomonas blattarum 13 (6.8%); Balantidium coli 4 (2.1%); and unclassified 16 (8.4%).

Conclusion

Lophomonas blattarum has previously been demonstrated in the gut of cockroaches, but this is the first assessment of the prevalence in Blattella germanica in faecal pellets. The presence of protozoa in faecal pellets provides some evidence for one step in a hypothesised route of respiratory infection whereby protozoa from household insects enter the respiratory tract.

New Insights into Cockroach Control: Using Functional Diversity of Blattella germanica Symbionts

Simple Summary

Insect hosts have close relationships with microbial symbionts. The limited metabolic networks of most insects are enhanced by these symbiotic relationships. Using symbiotic microorganisms for biological control of insects and insect-borne diseases has become an important research topic and shows potential for the development of applicable control approaches. Blattella germanica (L.) is public health pest worldwide; it is difficult to control because of its strong reproductive ability, adaptability, and resistance to insecticides. In this paper, the diverse biological functions (nutrition metabolism, reproductive regulation, insecticide resistance, defense, and behavior management) of symbionts, their interaction mechanism with hosts, and the research progress in the control of B. germanica are reviewed and discussed.

Abstract

Insects have close symbiotic relationships with several microbes, which extends the limited metabolic networks of most insects. Using symbiotic microorganisms for the biological control of pests and insect-borne diseases has become a promising direction. Blattella germanica (L.) (Blattaria: Blattidae) is a public health pest worldwide, which is difficult to control because of its strong reproductive ability, adaptability, and resistance to insecticides. In this paper, the diverse biological functions (nutrition, reproductive regulation, insecticide resistance, defense, and behavior) of symbionts were reviewed, and new biological control strategies on the basis of insect–symbiont interaction were proposed. We highlight new directions in B. germanica control, such as suppressing cockroach population using Wolbachia or paratransgenes, and combining fungal insecticides with synergistic agents to enhance insecticidal efficacy.

Anti-MRSA Activity of Actinomycin X2 and Collismycin A Produced by Streptomyces globisporus WA5-2-37 From the Intestinal Tract of American Cockroach (Periplaneta americana)

Methicillin-resistant Staphylococcus aureus (MRSA) is recognized as one of the serious pathogen that causes acquired infections worldwide. Its emerging need to discover novel, safe and potent anti-MRSA drugs. In this study, primary screening by anti-MRSA activity assay found one strain WA5-2-37 isolated from the intestinal tract of Periplaneta americana, exhibited great activity against MRSA ATCC 43300. The strain WA5-2-37 produced actinomycin X₂ and collismycin A which showed strong inhibition of MRSA with minimum inhibitory concentration (MIC) values of 0.25 and 8 μg/mL. The structures of the pure compounds were elucidated by analysis of mass spectrometry (MS), ¹H and ¹³C nuclear magnetic resonance (NMR). The strain WA5-2-37 was considered as Streptomyces globisporus on the basis of morphological characteristics, genotypic data, and phylogenetic analysis. This is the first reported naturally occurring strain of S. globisporus isolated from the intestinal tract of P. americana, whereas it has almost been found from plants, marine, and soil previously. Moreover, S. globisporus has not been reported to produce any anti-MRSA substances previously, such as actinomycin X₂ and collismycin A. In conclusion, the insect-derived strain of S. globisporus WA5-2-37 was considered of great potential as a new strain of producing actinomycin X₂, collismycin A or other anti-MRSA compounds.

New aspects about Crimean-Congo hemorrhagic fever (CCHF) cases and associated fatality trends: A global systematic review and meta-analysis

Crimean-Congo hemorrhagic fever (CCHF) is the most popular tick-borne disease causing by Crimean-Congo hemorrhagic fever virus (CCHFV). There are several valuable reviews considering some fields of the CCHF aspects. While there is no a systematic review about means and trends of CCHF cases and fatality rate, means and trends of CCHF cases and fatality rates of human occupations involved in CCHF. Therefore, this meta-analysis review performed to highlight and provide a global detailed of the above CCHF aspects. Among 398 collected papers, 173 papers were become this meta-analysis review. The study results confirm that an apparent increasing CCHF cases occurred through the past decades. The trends of annually and periodically CCHF cases and fatality rates were also increased. The means of annually and periodically CCHF cases and fatality rates were 57 and 432 cases, and 10 cases and 32.2 % and 49 cases and 28.8 %, respectively. The means of annually and periodically CCHF fatality rates are about one-tenth of CCHF human cases. The mean of CCHF fatality rates in Africa (22.0 %) is lower than Asia (33.5 %) and Europe (33.8 %). Among occupations involved in CCHF, agricultural (28.9 %), health-care (19.2 %) and slaughterhouse (16.7 %) workers, and farmers (13.9 %) had the maximum CCHF fatality rates in order. Based on literature review of CCHFV S-segment aspects, several clades and genotypes are reported to distribute in Africa, Asia and Europe regions. There are very wide fields to investigate the epidemiology characteristics of CCHFV clades, genotypes and their distribution in the future.

Mechanistic evaluation of gastro-protective effects of KangFuXinYe on indomethacin-induced gastric damage in rats

KangFuXinYe (KFX), the ethanol extract of the dried whole body of Periplaneta americana, is a well-known important Chinese medicine preparation that has been used to treat digestive diseases such as gastric ulcers for many years in China. However, its therapeutic effect and mechanism are not yet well understood. Thus, the aim of this study was to investigate the gastro-protective effects of KangFuXinYe (KFX) in indomethacin-induced gastric damage. Rats were randomly divided into six groups as follows: control, treated with indomethacin (35 mg·kg^-1), different dosages of KFX (2.57, 5.14 and 10.28 mL·kg^-1, respectively) plus indomethacin, and sucralfate (1.71 mL·kg^-1) plus indomethacin. After treatment, rat serum, stomach and gastric homogenates were collected for biochemical tests and examination of histopathology firstly. Rat serum was further used for metabolomics analysis to research possible mechanisms. Our results showed that KFX treatment alleviated indomethacin-induced histopathologic damage in rat gastric mucosa. Meanwhile, its treatment significantly increased cyclooxygenase-1 (COX-1), prostaglandin E₂ (PGE₂) and epidermal growth factor (EGF) levels in rat serum and gastric mucosa. Moreover, KFX decreased cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6) levels. Nine metabolites were identified which intensities significantly changed in gastric damage rats, including 5-hydroxyindoleacetic acid, indoxylsulfuric acid, indolelactic acid, 4-hydroxyindole, pantothenic acid, isobutyryl carnitine, 3-methyl-2-oxovaleric acid, sphingosine 1-phosphate, and indometacin. These metabolic deviations came to closer to normal levels after KFX intervention. The results indicate that KFX (10.28 mL·kg^-1) exerts protective effects on indomethacin-induced gastric damage by possible mechanisms of action (regulating tryptophan metabolism, protecting the mitochondria, and adjusting lipid metabolism, and reducing excessive indomethacin).

The cytotoxicity of malathion and essential oil of Nepeta crispa (lamiales: lamiaceae) against vertebrate and invertebrate cell lines

Introduction

Pesticides are used as essential tools to control vector-borne diseases and agricultural pests and maintain quality and quantity crop production. Scientists attempt to use derived plant natural products due to environmental safety and low mammalian toxicity. Therefore, the cytotoxicity of malathion and Nepeta crispa essential oil against vertebrate L929 and invertebrate Sf9 cell lines were investigated.

Methods

About 2×10³ cells were placed into the wells of a 96-well plate experiments. Then appropriate concentrations of malathion and N. crispa essential oil added to the wells. The cells were allowed to grow for 3-5 days and estimated the cell numbers. Control cell wells contained only cells with DMSO. All treatments and controls repeated at least four replicates.

Results

About 2×10³ cells were placed into the wells of a 96-well plate experiments. Then appropriate concentrations of malathion and N. crispa essential oil added to the wells. The cells were allowed to grow for 3-5 days and estimated the cell numbers. Control cell wells contained only cells with DMSO. All treatments and controls repeated at least four replicates.

Conclusion

Plant essential oil not only had no negative effects but also had boosting effects on the L929 cell viability. Nepeta crispa essential oil had negative effects on the Sf9 cell viability with the differences that derived plant natural products containing environmentally friendly and readily biodegradable derivatives, hydrolyzing rapidly in nature and nearly having no destructive effects on mammals and environment.

Comparing cytotoxicity of propoxur and Nepeta crispa (Lamiales: Lamiaceae) essential oil against invertebrate (Sf9) and vertebrate (L929) cell lines

Background and Aim:

Attempts to use the plant products are to be an appropriate option due to substantial concerns about human health and environmental problems of using synthetic pesticides. Therefore, the cytotoxicity of Nepeta crispa essential oil was compared with propoxur against invertebrate (Sf9) and vertebrate (L929) cell lines.

Materials and Methods:

The cell lines of Sf9 and L929 which were derived from the ovary glands of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) and mouse fibroblast cells, respectively, were obtained from the National Cell Bank of Pasteur Institute of Iran. About a number of 2 × 10³ cells were placed into the wells of 96-well plate experiments. Then, appropriate concentrations of essential oil of N. crispa plant and propoxur added to the wells. The cells were allowed to grow for 3-5 days and estimated the numbers of cells. The cells of control experiment wells contained only cells with dimethyl sulfoxide. All control and treatment experiments repeated at least four replicates.

Results:

Propoxur had negative effects on the viability of both invertebrate (Sf9) and vertebrate (L929) cell lines. The cytotoxicity of propoxur against invertebrate (Sf9) and vertebrate (L929) cell lines was gradually increased in accordance with propoxur concentrations. The cytotoxicity of N. crispa essential oil against vertebrate (L929) cell line was gradually decreased in accordance with plant concentrations, while the cytotoxicity of N. crispa essential oil against invertebrate (Sf9) cell line was strongly increased in accordance with plant concentrations.

Conclusion:

Plant essential oil not only had no negative effects but also had boosting effects on vertebrate cell viability. Essential oil of N. crispa plant had negative effects on invertebrate cell viability with the differences that the products derived from plants possessing of biodegradable and environmentally friendly derivatives, hydrolyzing rapidly in nature, and nearly having no destructive effects on environment, humans, or the mammals.

Contamination of Cockroaches (Insecta: Blattaria) by Medically Important Bacteriae: A Systematic Review and Meta-analysis

Cockroaches have the potential to disseminate bacteria in their environments and therefore a systematic review and meta-analysis was conducted to assess the state-of-the-art of our knowledge regarding bacterial contaminants of cockroaches. At least 78 bacterial species and 42 genera from 24 families and 11 orders of bacteria were reported to have contaminated cockroaches. At least 61, 42, 12, 13, 7, and 16 bacterial species have contaminated Blattella germanica (L.) (Blattaria: Ectobiidae), Periplaneta americana (L.) (Blattaria: Blattidae), Blatta orientalis (L.) (Blattaria: Blattidae), Diploptera punctata (Eschscholtz) (Blattaria: Blaberidae), Periplaneta fuliginosa (Serville) (Blattaria: Blattidae), and Supella longipalpa (F.) (Blattaria: Ectobiidae), respectively. Blattella germanica is the most commonly contaminated cockroach species, with the widest bacterial species diversity that threatens human health, followed by P. americana. Cockroach bacterial contaminants may result in the dissemination of opportunistic or pathogenic infections, particularly nosocomial and foodborne infections. One-way analysis of variance (ANOVA) revealed significant differences between bacterial contaminant species of cockroaches, species of cockroaches with bacterial contaminants, cockroach body part surfaces from the point of view bacterial contaminants and countries of cockroach infested with bacterial contaminants (P < 0.05). This statistical analysis indicates that the bacterial contaminants of the external cockroach body parts are potentially more harmful than from internal surfaces, and secondly, the bacterial contaminants of cockroaches in hospital environments are potentially more harmful than from other human environments. The survey indicated that the bacterial contaminant species of cockroaches appear to be mostly multiple drug resistant. The challenges of cockroaches as being potential vectors of pathogenic or opportunistic agents of human infections are discussed.

Update in Pediatric Asthma: Selected Issues

Asthma is a complex condition that affects 14% of the world's children and the approach to management includes both pharmacologic as well as non-pharmacologic strategies including attention to complex socioeconomic status phenomena. After an historical consideration of asthma, allergic and immunologic aspects of asthma in children and adolescents are presented. Concepts of socioeconomic aspects of asthma are considered along with environmental features and complications of asthma disparities. Also reviewed are links of asthma with mental health disorders, sleep disturbances and other comorbidities. A stepwise approach to asthma management is discussed that includes pharmacologic and non-pharmacologic strategies in the pediatric population. The role of immunotherapy and use of various immunomodulators are considered as well.

Instar Determination of Blattella asahinai (Blattodea: Ectobiidae) From Digital Measurements of the Pronotum Using Gaussian Mixture Modeling and the Number of Cercal Annuli

The Asian cockroach, Blattella asahinai Mizukubo, has expanded its range throughout the southeastern United States since its introduction into Florida. Unlike its closest relative, the German cockroach, Blattella germanica (L.), B. asahinai lives outdoors and can fly. There is little information on the biology and development of B. asahinai, including the number of instars during nymphal development. To estimate the number of instars of B. asahinai, nymphs were photographed, sexed, and the lengths and widths of their pronota were measured digitally. The number of instars of B. asahinai was estimated using Gaussian mixture models with the pronotal data. The most probable model and its clusters were selected to assign individuals to an instar. Instars were also determined by counting the number of cercal annuli of nymphs. Both clustering and cercal annuli indicated that B. asahinai most frequently had six instars when reared at 30°C. Growth did not strictly follow the Brooks-Dyar Rule, because nymphs had different numbers of instars and different growth patterns. Although Gaussian mixture models are not efficient for field sampling experiments, digital measurements may provide a way to estimate instars with live specimens in development studies without handling the animals in a way that may alter growth.

Crimean-Congo hemorrhagic fever (CCHF) seroprevalence: A systematic review and meta-analysis

Crimean-Congo haemorrhagic fever (CCHF) is the most widespread, tick-borne viral disease affecting humans and therefore this paper performed a meta-analysis to highlight seroprevalence features of CCHF in a global context. After a preliminary review of the 396 papers representing areas throughout the world, 206 were selected for detailed meta-analysis. In general the total means of CCHF seroprevalence were, respectively 4.7 and 24.6% for humans and animals; and 17.1, 18.9, 24.3, 29.3 and 27.1% for camels, cattle, goats, sheep and livestock. Statistical analysis revealed a significant difference in seroprevalence between humans and camels (P = 0.043), cattle (P = 0.010), goats (P = 0.015), sheep (P = 0.005) and livestock (P = 0.017). Regionally, there also was a difference between humans, and goats (P = 0.0001), sheep (P = 0.007) and livestock (P = 0.002). Globally, CCHF seroprevalence in at-risk professionals was 7.5 fold greater than in normal humans, while CCHF seroprevalence was 5 fold greater in animals, camels, cattle, goats, sheep and livestock than normal humans. Animal contact, animal husbandry, farming, tick bite history and secretion exposure were the most frequently reported CCHF seropositivity risk factors. This study serves as an important resource for epidemiological discussions related to CCHF and CCHF seroprevalence features, providing specific information in understanding human and animal mean and trend CCHF seroprevalence for different regions of the world and on an aggregate global scale; seroprevalence in at-risk professionals; and total mean and trend CCHF seropositivity involving risk factors.

Life history and functional capacity of the microbiome are altered in beta-cypermethrin-resistant cockroaches

Cockroaches are widely perceived to evolve resistance to insecticides. Over-expression of a resistance-conferring gene can be costly and may require energy and resource reallocation for metabolic and developmental processes. To evaluate whether changes in the composition of gut microbiota in Blattella germanica affected its resistance evolution to beta-cypermethrin and to determine the role of gut microbiota in host growth and development, we studied the relationship between insecticide resistance and the diversity and genetic content of gut microbiota in cockroaches. Results suggest beta-cypermethrin-resistant cockroaches (R strain) exhibited a delayed development period and reduced adult longevity compared with susceptible cockroaches (S strain). Based on 16S rRNA gene sequencing and community metagenomics, we found that the relative abundance of Lactobacillus and Acetobacteraceae were significantly lower in the R strain compared with the S strain in the foregut and midgut of both strains. Functional annotation of Kyoto Encyclopedia of Genes and Genomes (KEGG) modules of midgut genes in the two strains revealed that 10.6% were involved in metabolism, while the relative abundance in the R strain was 7.4%. Unigenes were also translated into amino acid sequences and assigned to protein families based on hits to the Carbohydrate-Active enzymes (CAZy) database. This process identified the glycoside hydrolases, glycosyl transferases and carbohydrate-binding modules of the S strain as all being significantly higher in diversity than those in the R strain. Overall, we conclude that fitness-related costs increased in the resistant strain of cockroaches compared with the susceptible strain, and the variation in insect gut microbiota, especially those related to growth and development, was an important influencing factor.

Comparative Proteomics Analysis Between the Short-Term Stress and Long-Term Adaptation of the Blattella germanica (Blattodea: Blattellidae) in Response to Beta-Cypermethrin

A proteomic method combining two-dimensional polyacrylamide gel electrophoresis and tandem mass spectrometry was used to compare the hemolymph expression profiles of a beta-cypermethrin-resistant Blattella germanica L. strain (R) and a susceptible strain (S) after 24 h of beta-cypermethrin induction. The results showed that there were 42 differentially expressed proteins after induction of the R strain: 4 proteins were upregulated and 38 proteins were downregulated. One hundred one hemolymph proteins were differentially expressed after induction of the S strain: 53 proteins were upregulated and 48 proteins were downregulated. The identified proteins were mainly classified into the following categories: energy metabolism proteins such as arginine kinase and triose phosphate isomerase, detoxification-related proteins such as glutathione S-transferases (GSTs), signal molecule-regulated proteins such as nitric oxide synthase (NOS), and other proteins such as kinetic-related proteins and gene expression-related proteins. Several proteins show significant differences in response to short-term stress and long-term adaptation, and differential expression of these proteins reflects an overall change in cellular structure and metabolism associated with resistance to pyrethroid insecticides. In summary, our research has improved the understanding of the molecular mechanisms of beta-cypermethrin resistance in German cockroaches, which will facilitate the development of rational methods to improve the management of this pest.

Effect of seasonality on the population density of wetland aquatic insects: A case study of the Hawr Al Azim and Shadegan wetlands, Iran

Aim:

Wetlands are extremely suitable ecosystems to assess the effect of climate change on the density of aquatic insects. This study aimed to assess the effect of seasonality on populations of aquatic insects in the Hawr Al Azim and Shadegan wetlands.

Materials and Methods:

The insect samplings were conducted at a large area of the Hawr Al Azim and five different sites of the Shadegan wetlands. In total, 18,534 arthropods of different life stages, including 12 orders containing 51 families, were collected and identified from the selected sites of the Shadegan and Hawr Al Azim wetlands.

Results:

Results showed that the population density of wetland aquatic insects gradually increased as the average daily temperature decreased, positively increased with daily mean relative humidity and precipitation, and decreased with the mean daily evaporation between October and April. Conversely, the population density of wetland aquatic insects gradually decreased with increasing average daily temperature and reduction of the mean relative humidity and precipitation and increasing the average evaporation from April to September. When differences between the average daily and water temperatures reached minimum in April, the population density of wetland aquatic insects reached maximum and turned mainly to families that they have high level of biological indices, indicating that wetlands have clean waters around the spring. While around the autumn conversely, they mostly changed to families that they have low level of biological indices, indicating that wetlands have unclean waters.

Conclusion:

The present study showed an optimum condition for the growth of insects around spring. Seasonality affects the population density of wetland aquatic insects during a year.

A Review on the Insecticide Resistance of Three Species of Cockroaches (Blattodea: Blattidae) in Iran

In Iran, there are four pest domestic species of cockroaches: Periplaneta americana (Linnaeus, Blattodea: Blattidae), Blatta orientalis (Linnaeus, Blattodea: Blattidae), Blattella germanica (Linnaeus, Blattodea: Blattidae), and Supella longipalpa (Fabricius, Blattodea: Blattellidae). The aim of this study was to compile and review studies conducted on insecticide resistance of domestic cockroaches in Iran to assess the current knowledge and gaps. Twenty insecticides were used in susceptibility testing of cockroaches. The bioassay methods varied, and included surface contact (exposure tests), topical applications and feeding studies on baits. Resistance ratio (RR) stated in the reviewed studies showed that B. germanica was resistant (RR > 10) to DDT, permethrin, and cypermethrin, while P. americana and S. longipalpa were categorized as low levels of resistance (RR = 1-2). S. longipalpa is newly reported from houses in some areas of Iran, including Tehran, and there are very few studies on its' biology, ecology and insecticidal resistance. Most studies used adult cockroaches, while the susceptibility status of nymphs was evaluated only in few studies. Use of different test methods and lack of a World Health Organization (WHO) updated procedure, including revised/updated insecticide diagnostic dosages and test kits. The lack of susceptible strains of cockroaches was a major challenge in the assessment of data. A comprehensive national program for monitoring susceptibility of household pests to insecticides in Iran is of great concern and is highly recommended.

Control of Cockroaches (Blattaria) in Sewers: A Practical Approach Systematic Review

Periplaneta americana (L.) (Blattaria: Blattidae), the American cockroach, is the most important invasive urban pest of sewer environments colonizing there with high significance of human public health and household allergens need to be controlled. Therefore this practical approach systematic review perform internationally to highlight and provide a detailed P. americana control in sewers. Of the 474 papers, 129 papers were selected to become this practical approach systematic review study of cockroach control in sewers. To control the American cockroaches, many studies have been conducted in various fields describing from an angle. The results were classified and discussed in getting cockroaches from sewers into buildings and their elimination, insecticide susceptibility, application of dust, bait and Inesfly paint insecticide formulations, biocontrol, and futuristic action categories. A recommending manner to achieve a successful P. americana cockroach control in sewers is using a combination of Integrated Pest Management (IPM) strategies resulted in significant reductions of cockroach infestations and asthma health outcomes. Use of P. americana breeding thelytoky, push-pull strategies and an automated sewer robot, and integrating health into the future buildings may be new approaches of P. americana control strategies.

Pest Cockroaches May Overcome Environmental Restriction Due to Anthropization

Our species have altered their surroundings since its early dispersion on Earth. Unfortunately, thanks to human-modified habitats, several pest organisms such as domiciliary insects have expanded their distributions. Moreover, pest-related microorganisms may also be aided by anthropization. Pest cockroaches are globally distributed and capable of carrying several diseases. We explored if urbanization may buffer environmental conditions allowing pest insects to expand their distribution. Specifically, we suggest that human settlements may generate suitable microhabitats for synanthropic cockroaches, helping them to survive and establish with disregard to overall climatic restrictions. To test this idea we studied the distribution of pest cockroaches spanning the length of Chilean territory. Chile, along its 4270 km length north to south extent, is a country offering a formidable sampling of Earth's climatic diversity accompanied by dense urbanizations. We studied entomological collections and spatially analyzed pest cockroach distribution found in Chile and discovered that synanthropic cockroach populations are consistently concentrated near most urban developed zones of the country and not limited by overall temperature. Furthermore, health-concern pest cockroach species were widely distributed in Chilean territory, found even in its most southern urban centers as well as Easter Island. Therefore, these disease vectors could exist even in isolated and extreme climatic zones as long as urbanization provides the adequate microhabitat. We discuss the need for further research in order to assess if these distributions can be extrapolated to the pathogenic strains these pest insects may be carrying as reported in other regions of the planet.

Bioactivity-Guided Screening of Wound-Healing Active Constituents from American Cockroach (Periplaneta americana)

Ethanol extract (EE) from Periplaneta americana (PA) is the main ingredient of Kangfuxin, which is a popular traditional chinese medicine (TCM) and has long been used for the clinical treatment of burns, wounds and ulcers. We compared the wound-healing activities of three extracts of PA using cutaneous wound-healing in mice as the bioactivity model. These three extracts were EE, total polysaccharide and total protein. We also tracked bioactive fractions in the EE by organic reagent extraction, column chromatography and HPLC. Seven compounds were successfully identified from the water elution fraction of the EE of PA using UPLC-MS. Among these compounds, four compounds (P2, P3, P4, P5(1)) were first reported in PA. Some of these compounds have been previously reported to have various pharmacological activities that could contribute to the high wound-healing activity of PA.