Larvicidial effects of essential oil and methanol extract of Achillea wilhelmsii C. Koch (Asteraceae) against Anopheles stephensi Liston (Diptera: Culicidae), a malaria vector

Background: Mosquitoes are responsible for the transmission of many pathogens and parasites and consequently serious diseases in humans. Currently, application of plant derivatives has been suggested as an alternative bio-control technique for these medically important vectors. Methods: In this study the essential oil and methanol extract of Achillea wilhelmsii were tested against late-3rd or young-4th instar larvae stages of mosquito vector, Anopheles stephensi, under laboratory condition. The larval mortality was calculated after 24 h of the exposure period. Data were subjected to Probit analysis in order to estimate the lethal concentration for 50% and 90% of mortality values. Results: Results showed that the essential oil induced 100% larval mortality of An. stephensi larvae after 24 h with a dosage of 160 ppm, However, a dosage of 320 ppm of methanol extract was required to reach 100% larval mortality.The essential oil methanol extract exerted significant larvicidal activity with LC50 values of 39.04 and 115.73 ppm, respectively. Conclusion: Our finding suggests that A. wilhelmsii oil is a potential source and has valuable larvicidal compounds for mosquito larval control. © 2017, Kerman University of Medical Sciences. All rights reserved

Detection of cyfluthrin resistance mechanisms among German cockroach strains in vivo in Kashan during 2011-2012

Background: Development of insecticide resistance is a serious problem in the control of German cockroach population in home and hospital. Knowledge about the resistance mechanisms would help us to control the pest. This study was conducted to determine the cyfluthrin resistance in German cockroaches using the piperonyl butoxide (PBO). Materials and Methods: In this study, cyfluthrin (4-6 concentration ranges) was used on susceptible strains- for ten years without any contact with the lab-grown poison - with the mortality rate ranged from 0 to 100. After determining the concentrations of the cyfluthrin in the susceptible strains, the level of susceptibility and resistance mechanism in the wild strains were determined using PBO in vivo. Data were analyzed using Probit program. Results: Lethal dose (LD50) and resistance ratio (RR) for susceptible and three wild strains were 133.43-503.6 and 1.48-3.77, respectively. LD50 of cyfluthrin+PBO and synergist ratio for susceptible and three wild strains were 51.3-490.53 and 1.03-2.43, respectively. Conclusion: All three collected strains showed different levels of resistance compared to the susceptible strains. In almost all strains, PBO considerably increases the cyfluthrin toxicity. The findings signify the involvement of monooxygenase in cyfluthrin resistance

Epidemiology of Head Lice Infestation in Primary SchoolPupils, in Khajeh City, East Azerbaijan Province, Iran

Background: Pediculus capitis (Anoplura: Pediculidae) or head louse is an obligate ectoparasite transmitted mainly through physical contact. This study was conducted to survey the prevalence of head lice infestation rate and some risk factors in Primary School pupils, in Khajeh City East Azerbaijan Province, Iran. Methods: We selected 20 primary schools of Khajeh City during 2008 and 2009. Totally 500 pupils including 200 boys and 300 girls from all grade 1-5 were selected by multistage, systematic random sampling in rural areas of Khajeh City and were examined for lice. In addition, a standard questionnaire recorded information about demographic features of each pupil. Results were analyzed by SPSS software. Results: The total prevalence of head lice infestation in this study was 4.8%. and the prevalence rate was significantly higher in girls (6.66%) than in boys (2%). Epidemiological factors such as: sex, school grade, family size, parent's education, type of house, hair washing (per week), number of using comb per day, were evaluated and results showed significant difference in head lice infestation and sex, school grade ,family size ,father education ,and type of house (P< 0.05). Conclusion: Pediculosis is a public health problem in many parts of the world, and due to the higher prevalence of pediculosis in crowded families, family by lower levels of father's education and socioeconomic status in our study and rural area, it is necessary to give health education for families to prevent of pediculosis in this area

Survey of Optimal Methods for the Control of Cockroaches in Sewers of Qom City

"n "nBackgrounds and Objectives: Domestic sewers and wastewater treatment plants are suitable places for the growth of some types of Cockroaches. Annually the water and wastewater company of Qom city make considerable attempts to overwhelm the problem. The current study is aimed to determine types of Cockroaches and select the optimal methods for their control."nMaterials andMethods: In this study, 120 manholes are selected in different locations of Qom city, the numbers of Cockroaches are counted and the Cockroaches are classified into different groups. Then, each group are faced to different insecticides Including Simperator, Diazinon , Dursban Ec, Faikam, Sipermetrin, Icon, Deltametrina and Sulfac. One group of manholes was considered as blank sample during one month. Counting and determination of Cockroaches in these manholes conducted before using insecticides and also five months after it."nResults: the study showed that all sewers were 100% polluted by Cockroaches. The number of Cockroaches in manholes range from minimum 4 to maximum 3600 in each manhole. The applied of insecticides including Dursban Ec, Simperator, Sulfac, Dursban, and Deltametrina are used 2 gr in 100 square meter of area of each sewer. The Cockroaches population reduced to approximately zero after application of these insecticides. Spraying sewers by Simperator controlled 100% of Cockroaches."nConclusion: the most effective method for the control of Cockroaches was usage of 2 gr of Dursban (Ec) in squaremeter of area in the beginning of warmseason.If we use 1-1/5months interval between the time of spraying insecticide in selected wells, with using simperator and dursban (Ec) we can overwhelm Cockroaches using Simperator and Dursban Ec. The results of statistical analysis show that reduction of number of coackroaches in one month after using poison is significant (P-value&lt; 0.05). But after 5months it lose meaningful in all of them.Also, reduction of number of coackroachesin blank manholes was not statistically significant

Phytochemical Profile and Mosquito Larvicidal Activity of the Essential Oil from Aerial Parts of Satureja bachtiarica Bunge Against Malaria and Lymphatic Filariasis Vectors

Mosquitoes play an important role in transmission of large number of diseases including malaria, filariasis and arboviral diseases. Increasing application of synthetic insecticides may be resulted in resistant to insecticides. Furthermore, it may have adverse effects on the environment and human health. Currently, one of the most effective alternative approaches under the biological control programs is using of natural larvicidal agents derived from plants. The larvicidal properties of essential oil obtained from the aerial parts of an indigenous plant, Satureja bachtiarica was evaluated against two mosquito vector, Anopheles stephensi and Culex quinquefasciatus. In addition, the analysis of essential oil was investigated by Gas chromatography-Mass spectrometry (GC-MS). Forty-one compounds, representing 98.42% of the essential oils have been identified. The main constituents were carvacrol (22.66%), p-cymene (15.89%), borneol (14.05 %), 1,8-cineole (10.45%) and thymol (7.27%). Five different concentrations of essential oil were evaluated against the late 3rd and early 4th instars larvae of An. stephensi and Cx. quinquefasciatus. The LC50 and LC90 values against An. stephensi larvae were 24.27 and 54.24 ppm and for Cx. quinquefasciatus were 44.96 and 114.45 ppm after 24 hours of exposure, respectively. In conclusion, results of study clearly indicated that the essential oils of S. bachtiarica possessed remarkable larvicidal properties and could serve as an alternative to synthetic insecticides for control of mosquito larvae

Chemical Composition and Mosquito Larvicidal Properties of Essential Oil from Leaves of an Iranian Indigenous Plant Zhumeria majdae

The use of natural products derived from plants in mosquitoes control is an alternative method for minimizing the side effects of chemical pesticides on the environment. In the current study chemical composition of essential oil extracted from an indigenous plant, Zhumeria majdae was determined and identified by gas chromatography (GC) and GC-mass spectrometry (MS) analysis. In addition, the larvicidal activity of essential oil was evaluated against two important mosquito vectors, Anopheles stephensi and Culex quinquefasciatus. Thirty constituents, representing 97.86 of the oil, were identified. The main constituents of the oil were camphor (38.84 ), linalool (31.18 ) and camphene (7.73 ). Z. Majdae volatile oil showed significant toxicity against larvae of both species. The LC50 and LC90 values against An. stephensi larvae were 61.34 and 135.81 ppm and for Cx. quinquefasciatus were 88.51 and 191.56 ppm after 24 hours, respectively. Our findings indicated that the essential oil from Z. majdae leaves may be explored as a potential mosquito bio-larvicide. © 2016 Har Krishan Bhalla & Sons

Diversity of Phlebotomine sand flies (Diptera: Psychodidae) in mountainous and plain areas of an endemic focus of anthroponotic cutaneous leishmaniasis in Iran

Objective: To determine the diversity of sand flies in different biotopes of mountainous and plain areas of Bam County as the most infected focus of anthroponotic cutaneous leishmaniasis in southeast Iran, and synanthropic index of Phlebotomus sergenti Parrot, and Phlebotomus papatasi Scopoli as the main vectors of cutaneous leishmaniasis in Iran. Methods: Sand flies were captured once a month using sticky traps in domestic, peri-domestic, agricultural, and sylvatic biotopes in the plain and mountainous areas. Alpha diversity indices, including richness, evenness, Shannon-Wiener; beta diversity indices (Jaccard's and Sorensen's similarity indices) and synanthropic index were calculated. Results: A total of 2 664 specimens of 9 sand fly species were collected from mountainous (47) and plain (53) areas. Species richness, species evenness, and Shannon-Wiener indices were obtained as 9, 0.637, and 1.399, respectively in the mountainous area. Phlebotomus sergenti and Phlebotomus papatasi were constant species with the synanthropic index of-18.463 and-29.412, respectively. In addition, species richness, species evenness, and Shannon-Wiener indices were 4, 0.690, and 0.956, respectively in the plain area. Phlebotomus sergenti and Phlebotomus papatasi were dominant species with the synanthropic index of +9.695 and +36.207, respectively. Similarity indices were low among different biotopes of plain and mountainous areas. Conclusions: A basic knowledge about the diversity of sand flies in various biotopes is essential to design sound control programs. Biodiversity and synanthropic indices of sand flies are different in plain and mountainous areas due to the difference in biotic and abiotic factors between the two areas. © 2020 Asian Pacific Journal of Tropical Biomedicine Produced by Wolters Kluwer Medknow. All rights reserved

Detection of bendiocarb and Carbaryl resistance mechanisms among German cockroach Blattella germanica (Blattaria: Blattellidae) collected from Tabriz Hospitals, East Azerbaijan Province, Iran in 2013

Background: Insecticide resistance is one of the serious problems for German cockroach control program. This study was conducted to determine the bendiocarb and Carbaryl resistance mechanisms in German cockroaches using the piperonyl butoxide (PBO). Methods: Bioassay tests were conducted with 4 to 6 different concentrations of both insecticides with four replicates of 10 susceptible strain cockroaches per concentration to determine of discriminative concentration. After determining discriminative concentration, the result was compared to wild strain. The levels of susceptibility and resistance ratio (RR) and synergism ratio (SR) were calculated for each five wild strains. Moreover resistance mechanisms in wild strains were determined using PBO synergist in vivo. Results: Hospital strains showed different levels of resistance to bendiocarb and carbaryl compared to susceptible strain. The bendiocarb and carbaryl resistance ratios ranged from 2.11 to 7.97 and 1.67 to 2 at LD50 levels, respectively. The synergist PBO significantly enhanced the toxicity of bendiocarb and carbaryl to all strains with different degrees of synergist ratio, 1.31, 1.39, 3.61, 1.78, 1.62 and 2.1 fold for bendiocarb, 1.19, 1.18, 1.12. 1.29, 1.45 and 1.11- fold for carbaryl, suggesting monooxygenase involvement in bendiocarb and carbaryl resistance. Conclusion: The synergetic effect of PBO had the highest effect on bendiocarb and resistance level was significantly reduced, which indicates the important role of monoxidase enzyme in creating resistance to Bendiocarb. Piperonyl butoxide did not have a significant synergistic effect on carbaryl and did not significantly break the resistance

Evaluation of different attractive traps for capturing sand flies (diptera: Psychodidae) in an endemic area of leishmaniasis, Southeast of Iran

Background: The attraction of phlebotomine sand flies to plant and animal hosts is due to the produced chemical compounds, affecting the olfactory receptors of the insects. Therefore, novel and effective methods, such as Attractive Toxic Sugar Baits (ATSB) and Attractive Toxic Baits (ATB), are based on the effective materials that attract sand flies toward the host. The present study was designed to identify the attractive materials in plants and animals for using in ATSB and ATB. Methods: This cross-sectional study was carried out in July 2018 on endemic areas of leishmaniasis in Iran. Different baits, including mango, nectarine, grape, banana, melon and watermelon, defibrinated blood of cattle, sheep, goat and chicken, urine of cattle, sheep, goat and ultimately, simple and complex chemicals, such as CO2, 1-octanol, lactic acid and human sweat were placed inside the traps, and the rate of the sand flies attraction to these materials was studied. Furthermore, data were analyzed using the Kruskal-Wallis test and Mann Whitney U test. Results: There was a significant difference in the sand flies attraction between the traps containing watermelon, urine of cattle, and sheep, and chemicals such as CO2 and human sweat and the control trap (p< 0.05). Conclusion: This study showed that watermelon and CO2 are the potential candidates for using in ATSB and ATB, respectively. © 2020 Tehran University of Medical Sciences. All rights reserved