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Objective: To determine the significance of temperature, rainfall and humidity in the seasonal abundance of Anopheles stephensi in southern Iran. Methods: Data on the monthly abundance of Anopheles stephensi larvae and adults were gathered from earlier studies conducted between 2002 and 2019 in malaria prone areas of southeastern Iran. Climatic data for the studied counties were obtained from climatology stations. Generalized estimating equations method was used for cluster correlation of data for each study site in different years. Results: A significant relationship was found between monthly density of adult and larvae of Anopheles stephensi and precipitation, max temperature and mean temperature, both with simple and multiple generalized estimating equations analysis (P<0.05). But when analysis was done with one month lag, only relationship between monthly density of adults and larvae of Anopheles stephensi and max temperature was significant (P<0.05). Conclusions: This study provides a basis for developing multivariate time series models, which can be used to develop improved appropriate epidemic prediction systems for these areas. Long-term entomological study in the studied sites by expert teams is recommended to compare the abundance of malaria vectors in the different areas and their association with climatic variables. [ABSTRACT FROM AUTHOR]

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Objective To determine the larvicidal activities of petroleum ether, chloroform, ethyl acetate and methanol fractions of roots and fruits extracts of Astrodaucus persicus from Apiaceae family against malaria vector, Anopheles stephensi ( An. stephensi ). Methods Twenty five third instar larvae of An. stephensi were exposed to various concentrations (10–160 g/L) of fractions and were assayed according to World Health Organization protocol. The larval mortality was calculated after 24 h treatment. Results Among tested fractions, the highest larvicidal efficacy was observed from ethyl acetate fraction of fruits extract with 50% and 90% mortality values (LC 50 and LC 90 ) of 34.49 g/L and 108.61 g/L, respectively. Chloroform fraction of fruits extract was the second larvicidal sample with LC 50 of 45.11 g/L and LC 90 of 139.36 g/L. Petroleum ether fractions of fruits and roots and methanol fraction of fruits showed moderate toxicity against An. stephensi . Conclusions Astrodaucus persicus is a potential source of valuable and natural larvicidal compounds against malaria vector, An. stephensi and can be used in mosquitoes control programs as an alternative to synthetic insecticides. [ABSTRACT FROM AUTHOR]

Objective To determine the wash resistance of Olyset ® Plus using World Health Organization Pesticide Evaluation Scheme standard washing procedure and to assess the value of knock down and mortality rates of Anopheles stephensi at different regimens of long lasting insecticide treated nets washings. Methods The study was conducted at the Bioassay Laboratory of Culicidae Insectary, School of Public Health, Tehran University of Medical Sciences, Iran. The net was made of polyester impregnated with permethrin and piperonyl butoxide at a ratio of 2:1. The washing resistance was assessed using Le Chat ® soap and a shaker incubator set at a speed of 155 r/min, 30 °C for 10 min. The cone bioassay test was carried out according to World Health Organization recommended guideline with tolerant field strain of female Anopheles stephensi to pyrethroids. Results The knockdown and mortality rates of female mosquitoes exposed to Olyset ® Plus from un-washed nets to 2 washings were 79.7% and 88.8% respectively. Mortality was dropped to zero while active ingredient estimated 0.532 μg/100 cm 2 to 0.481 μg/100 cm 2 after 15 washings. A positive correlation was seen between residues of permethrin on nets, knockdown rate and mortality rate of female Anopheles stephensi exposed to different regimes of washed Olyset ® Plus ( r = 0.954, P = 0.001). Conclusions It is recommended that a preliminary survey conducted on resistance level of Anopheles vectors before the distribution of Olyset ® Plus in malaria endemic communities. [ABSTRACT FROM AUTHOR]

Objective To determine the susceptibility status of Anopheles maculipennis ( An. maculipennis) against the major insecticides used in the health sectors in West Azarbaijan Province, Northwestern Iran. Methods Unfed 3-5 days old adult females of An. maculipennis were collected across the West Azarbaijan Province and were subjected to evaluation of their susceptibility following World Health Organization recommended protocol against six insecticides (permethrin, deltamethrin, propoxur, bendiocarb, malathion and dieldrin) belonging to four different classes. Results In this study, 916 specimens of An. maculipennis were examined against the insecticides which indicated that An. maculipennis was tolerant to permethrin, deltamethrin and dielderin, but displayed resistance against propoxur, bendiocarb and malathion. Conclusions The pattern of resistance in An. maculipennis could be attributed to the agricultural landscapes, agricultural pesticides used and the exposure of the mosquitoes to insecticides. Logical cooperation is needed between the agriculture and health sectors to ensure the judicious use of pesticides in each sector and the management of probable resistance. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To determine the effects of environmental parameters of larval habitats on distribution and abundance of anopheline mosquitoes in Rudan county of Iran. Methods: This cross-sectional study was conducted during the mosquito breeding season from February 2010 to October 2011. The anopheline larvae were collected using the standard dipping method. The specimens were identified using a morphological-based key. Simultaneously with larval collection, environmental parameters of the larval habitats including water current and turbidity, sunlight situation, and substrate type of habitats were recorded. Water samples were taken from breeding sites during larval collection. Before collection of samples, the water temperature was measured. The water samples were analysed for turbidity, conductivity, total alkalinity, total dissolved solid, pH and ions including chloride, sulphate, calcium, and magnesium. Statistical correlation analysis and ANOVA test were used to analyze the association between environmental parameters and larval mosquito abundance. Results: In total 2 973 larvae of the genus Anopheles were collected from 25 larval habitats and identified using morphological characters. They comprised of six species: An. dthali (53.21%), An. stephensi (24.22%), An. culicifacies (14.06%), An. superpictus (4.07%), An. turkhudi (3.30%), and An. apoci (1.14%). The most abundant species was An. dthali which were collected from all of the study areas. Larvae of two malaria vectors, An. dthali and An. stephensi, co-existed and collected in a wide range of habitats with different physico-chemical parameters. The most common larval habitats were man-made sites such as sand mining pools with clean and still water. The anopheline mosquitoes also preferred permanent habitats in sunlight with sandy substrates. The results indicated that there was a significant relationship between mean physico-chemical parameters such as water temperature, conductivity, total alkalinity, sulphate, chloride, and mosquito distribution and abundance. Conclusions: The results of this study showed a correlation between certain environmental parameters and mosquito larvae abundance, and these parameters should be considered in planning and implementing larval control programs. [Copyright &y& Elsevier]

Abstract: Objective: To investiagte insecticide resistance in target species for better insecticide resistance managemnet in malaria control programs. Methods: The status of insecticide resistance to different imagicides in Anopheles stephensi (An. stephensi) including DDT 4%, lambdacyhalothrin 0.50%, deltamethrin 0.05%, permethrin 0.75%, cyfluthrin 0.15% and etofenprox 0.50% was performed according to WHO standard method. Results: The mortality rate to lambdacyhalothrin, permethrin, cyfluthrin, deltamethrin, etofenprox and DDT was (88.0±3.2), (92.0±2.7), (52.0±5.0), (96.0±2.2), (90.0±3.0) and (41.0±5.7) percent, respectively at diagnostic dose for one hour exposure time followed by 24 h recovery period. Conclusions: These results showed first indication of pyrethroid resistance in An. stephensi in a malarious area, from southern Iran. There is widespread, multiple resistances in the country in An. stephensi to organochlorine and some report of tolerance to organophosphate insecticides and recently to pyrethroids. However, results of this paper will provide a clue for monitoring and mapping of insecticide resistance in the main malaria vector for implementation of any vector control. [Copyright &y& Elsevier]

Abstract: Objective: To determine the susceptibility and irritability level of malaria vector Anopheles sacharovi (An. sachrovi) to different insecticides in a malaria-prone area. Methods: Susceptibility and irritability levels of field collected strain of An. sacharovi to WHO standard papers of DDT 4%, dieldrin 0.4%, malathion 5%, fenitrothion 1%, permethrin 0.75%, and deltamethrin 0.05% were determined in East Azerbaijan of Iran during reemerging of malaria as described by WHO. Results: Results showed that at the diagnostic dose of insecticides this species exhibited resistance to DDT, tolerant to dieldrin and but somehow susceptible to fenitrothion, malathion, permethrin and deltamethrin. The results of irritability of this species to DDT, lambdacyhalothrin, permethrin cyfluthrin and deltamethrin revealed that DDT had had the most and deltamethrin the least irritancy effect. The average number of take offs/fly/minutes for DDT was 0.8±0.2. The order of irritability for permethrin, lambdacyhalothrin, cyfluthrin and deltamethrin were 0.7±0.2, 0.5±0.2, 0.5±0.3, and 0.2±0.1, respectively. Conclusions: Results of this study reveals the responsiveness of the main malaria vector to different insecticides. This phenomenon is depending on several factors such as type and background of insecticide used previously, insecticide properties, and physiology of the species. Careful monitoring of insecticide resistance and irritability level of species could provide a clue for appropriate selection of insecticide for malaria control. [Copyright &y& Elsevier]

Dung beetles (family Scarabaeidae) are one of the largest families of beetles worldwide. Due to biological behavior of these arthropods, they are considered to play an important role in the life cycle of some helminths. In the present study, dung beetles collected from cattle pastures in rural areas of Ardabil province, north-west of Iran were examined for infection with larval stages of helminths. According to the results, nematodes of 2 genera were identified including Rhabditis and Gongylonema. The more common species was Rhabditis sp. which was found in 9 species of beetles. Out of 15 different species of dung beetles, Copris lunaris was the only scarabaeid to be found naturally infected with the larval stages of Gongylonema sp. Our new findings introduce C. lunaris as a potential biological vector for transmission of Gongylonema sp. to vertebrates in the surveyed region. [ABSTRACT FROM AUTHOR]

Objective To evaluate the insecticidal effect of diatomaceous earth (DE) against adults and nymphs of Blattella germanica . Methods This cross sectional study has been done on the laboratory strain of German cockroaches. Two stages, nymph and adult, were exposed to six dose rates of the DE, 2.5, 5, 10, 15, 20 and 25 g/m 2 , at 24, 48 and 72 h exposure period. Mortality (number of dead cockroaches) was assessed after 24 h. Other exposed specimens were transferred to the beakers contained food and water for counting the retard mortality rate after 1 week. Results Increasing in dose rates of DE increased mortality rate, so that the lowest and highest mortality rates were observed in 2.5 and 25 g/m 2 , respectively. The results of the statistical analysis showed no significant difference in the lethality of 50% of DE plus water on the German cockroach nymphs. Conclusions Due to the resistance of German cockroach against organochloride, organophosphorus, carbamate and pyrethriodes insecticides, it is suggested to use DE for insect's control. [ABSTRACT FROM AUTHOR]

Objective To determine the effects of environmental characteristics of larval habitats on distribution and abundance of anopheline mosquitoes in Bashagard county, a malarious area in southeast of Iran. Methods Larvae were collected monthly using the standard dipping method and identified using a morphological-based key. Environmental characteristics of the larval habitats were recorded. Water samples were taken from habitats during larval collection for physico-chemical characterization. Statistical analyses were performed. Results In total 5 150 anopheline larvae from 36 larval habitats were collected and identified. They comprised of six species: Anopheles culicifacies (29.36%), Anopheles moghulensis (25.20%), Anopheles dthali (18.02%), Anopheles superpictus (17.24%), Anopheles turkhudi (5.17%) and Anopheles stephensi (5.01%). The most common larval habitats were natural and clear water bodies such as riverbeds with sandy substrates and still water. Furthermore, the anopheline larvae were abundant in permanent and full sunlight habitats without vegetation and algae. Larval density was positively correlated with water temperature. Chemical characteristics including conductivity, total alkalinity, sulphate and chloride had significant effects on distribution and abundance of anopheline species. Conclusions The result of this study indicates a correlation between some environmental characteristics and anopheline larvae abundance which can be considered for effective planning and implementing malaria elimination program in Iran. [ABSTRACT FROM AUTHOR]