Dragonflies as an Important Aquatic Predator Insect and Their Potential for Control of Vectors of Different Diseases

Mosquitoes belong to order of Diptera. The main important vectors are genus Aedes, Culex and Anopheles. They transmit different agents such bacteria, viruses, and parasites. According to the latest information around 7 hundred million people around the world are suffering from mosquitoborne illness resulting over one million deaths. The main important disease transmitted by Anopheles is malaria. Other genus of mosquitoes including Aedes and Culex species transmit different arboviral disease to human. According to guideline of World Health Organization, the mina control of disease is vectors control. The main important vector control is using different insecticides. Using chemical insecticides for controlling mosquitoes is limited because they develop resistance against these insecticides. So, efforts have been made to control the mosquito vectors by eco-friendly techniques. In this research all, the relevant information regarding the topic of research is research through the internet and used in this paper. An intensive search of scientific literature was done in “PubMed”, “Web of Knowledge”, “Scopus”, “Google Scholar”, “SID”, etc Results shows that one of important environmental friendly vector control is biological control, using different predators and other microorganisms for vector and pest control. Dragonflies do eat mosquitos and serve as mosquito predators. They feed on mosquitos and reduce their number in outdoor areas. The dragonflies are scary biters, but they are dangerous to mosquitos. Worldwide results showed that dragonflies are able to control Aedes, Culex and Anopheles mosquito species. The artificial rearing of these predators and releasing for biological control is an appropriate measure for vector control worldwide

Malaria elimination in Iran, importance and challenges

Background: The aim of study is to assess the importance and challenges of Malaria elimination (ME) in Iran's health system. Material: Opinion of experts from Ministry of Health and Medical Education and the chancellors of medical universities affected by malaria were gathered using Focus Group Discussions and in­depth interviews. We asked them about the importance and main challenges of ME in Iran. Results: Main factors on importance of ME were: it's a struggle to reach to equity in the poorest regions of county, prevention of emerging disease in susceptible regions, lowering the cost of control and its effects on the region's socioeconomic condition. Main challenges were Iran's long border with malaria­endemic countries Pakistan and Afghanistan and illegal immigrants, underdevelopment in rural areas, system's insensitivity and diagnosis problem due to reduction of cases. Conclusion: Quantitative and holistic researches are needed for assessing the consequences of ME

Cost effectiveness of Malaria interventions from preelimination through elimination: a study in Iran

Background: Malaria still is considered as a public health problem in Iran. The aim of the National Malaria Control Department is to reach the elimination by 2024. By decreasing the number of malaria cases in preelimination phase the cost effectiveness of malaria interventions decreases considerably. This study estimated the cost effectiveness of various strategies to combat malaria in preelimination and elimination phases in Iran. Methods: running costs of the interventions at each level of intervention was estimated by using evidence and expert opinions. The effect of each intervention was estimated using the documentary evidence available and expert opinions. Using a point estimate and distribution of each variable the sensitivity was evaluated with the Monte Carlo method. Results: The most cost-effective interventions were insecticide treated net (ITN), larviciding, surveillance for diag- nosis and treatment of patients less than 24 hours, and indoor residual spraying (IRS) respectively, No related evi- dence found for the effectiveness of the border facilities. Conclusion: This study showed that interventions in the elimination phase of malaria have low cost effectiveness in Iran like many other countries. However ITN is the most cost effective intervention among the available interventions

Larvicidal activity of essential oil and methanol extract of Nepeta menthoides against malaria vector Anopheles stephensi

AbstractObjectiveTo investigate the larvicidal activity of essential oil and methanol extract of the Nepeta menthoides (N. menthoides) against main malaria vector, Anopheles stephensi (An. stephensi).MethodsThe essential oil of plant was obtained by Clevenger type apparatus and the methanol extract was supplied with Percolation method. Larvicidal activity was tested by WHO method. Twenty five fourth-instar larvae of An. stephensi were used in the larvicidal assay and four replicates were tested for each concentration. Five different concentrations of the oil and extract were tested for calculation of LC50 and LC90 values.ResultsThe LC50 and LC90 values were determined by probit analysis. LC50 was 69.5 and 234.3 ppm and LC90 was 175.5 and 419.9 ppm for the extract and essential oil respectively.ConclusionsAccording to the results of this study methanolic extract of plant exhibited more larvicidal activity than essential oil. This could be useful for investigation of new natural larvicidal compounds

Control of American Cockroach (Periplaneta americana) in Municipal Sewage Disposal System, Central Iran

Background: Cockroaches consists of 4000 species, of which 40 species are serious domestic pests. They have involved the mechanical transmission of various pathogenic viruses, bacteria, and protozoans to humans. This study aimed to determine different control methods of P. americana in sewage system of Esfahan City, central Iran using different insecticides recommended by WHO. Methods: Totally, 164 manholes with at least more than three cockroaches were selected until 2017 for this study. The species of cockroaches were identified; the adults and nymphs were counted and recorded. Each sewer shaft was assigned to one treatment method in an ascending order of number of cockroaches counted, coding the treatment method with paint on the lower part of the wall near the manhole cover. The manhole shafts were then inspected at 1 and 5 months’ post-treatment. Data analyzed by statistical methods.Results: Almost all of the products (Excluding boric acid with bait formulation) resulted in appropriate control with­in one month of application. The appropriate products for chemical control of cockroaches were the chlorpyrifos 5% Emulsifiable Concentrate (EC), diazinon 5% (EC), diazinon 0.05% (EC) and cypermethrin 5% Fog. These pesticides achieved an optimal reduction of population providing more than 90% control of cockroaches for five consecutive months. Conclusion: The emulsifiable concentrates and fog formulations in the control were more successful compared to other methods and this was penetration deep into the hiding places of cockroaches.</p

Evaluation of biological control agents for mosquitoes control in artificial breeding places

ObjectiveTo evaluate the entomological impact of chlorpyrifos-methyl, Bacillus thuringiensis, and Gambusia affinis on mosquitoes control in artificial breeding places.MethodsA Latin square design with 4 replicates was performed in order to evaluate the efficacy of chlorpyrifosmethyl, Bacillus thuringiensis, and Gambusia affinis on larva. The larvicide was applied at the dosage of 100 mg a.h/ha, Bacillus thuringiensis at the recommended dosage and 10 fishes per m2 were applied at 1×1 m2 artificial breeding sites. The larval densities for both anopheline and culicine were counted according to larvae /10 dippers prior and 24 h after application.ResultsAll three control agents are effective for mosquito density reduction, and the difference between the three agents and the control is significant (P<0.05). There is also significant difference among chlorpyrifos-methyl, Bacillus thuringiensis and Gambusia affinis. Bacillus thuringiensis exhibited more reduction on mosquito larval density than fish and larvicide (P<0.05).ConclusionsBacillus thuringiensis in comparison with two other agents is the appropriate method for larviciding in the breeding places. Although long term assessing for biological activities as well as monitoring and mapping of resistance is required

Worldwide Status of Insecticide Resistance of Aedes aegypti and Ae. albopictus, Vectors of Arboviruses of Chikungunya, Dengue, Zika and Yellow Fever

Background: Controlling of Aedes aegypti and Ae. albopictus, vectors of five important mosquito-borne diseases, is known as the most effective method to prevent the transmission of arboviruses to humans, but the emergence of insecti­cide resistance is threat for control and prevention of vector borne diseases. A better understanding of mosquito re­sistance to insecticides will help to develop more effective methods to control insecticide resistance in mosquito vectors. Methods: Worldwide geographical distribution of insecticide resistance in Ae. aegypti and Ae. albopictus by the availa­ble papers and map of the data for carbamates, organochlorines, organophosphates, pyrethroids, microbial and insect growth regulator insecticides were reviewed. Article data published up to December 2022 were investigated by search­ing the following databases: "Google Scholar", "PubMed", "Scopus", "SID" and "Web of Knowledge". Results: The results showed that the susceptibility and resistance status of Ae. aegypti and Ae. albopictus to insecticides in the world is very diverse. Conclusion: Due to the importance of Ae. aegypti and Ae. albopictus in the transmission of mosquito-borne arbovirus­es, resistance management should be given more attention worldwide to prevent insecticide resistance in the arbovirus vector and replace the new approach for vector control

The insecticidal effect of diatomaceous earth against adults and nymphs of Blattella germanica

ABSTRACTObjectiveTo evaluate the insecticidal effect of diatomaceous earth (DE) against adults and nymphs of Blattella germanica.MethodsThis 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/m2, 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.ResultsIncreasing in dose rates of DE increased mortality rate, so that the lowest and highest mortality rates were observed in 2.5 and 25 g/m2, 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.ConclusionsDue to the resistance of German cockroach against organochloride, organophosphorus, carbamate and pyrethriodes insecticides, it is suggested to use DE for insect's control