Species composition and abundance of mosquito larvae in relation with their habitat characteristics in Mazandaran Province, northern Iran

Abstract

Mosquitoes transmit a variety of diseases to humans. Their abundance and distribution are related to the characteristics of larval habitats. Mosquito larvae were collected from 120 natural and artificial habitats in 30 villages of 16 counties using standard 350 ml dippers and pipette, on a monthly basis from May-December 2014 in Mazandaran Province, northern Iran. Larval habitat characteristics were recorded separately, based on the conditions of the habitats (permanent or temporary, stagnant or running), type of habitats (natural or artificial), vegetation, exposure to sun, type of bed, water condition (clear or turbid), expanse (m), depth (cm, m) and temperature (°C) of habitats. The relationship between larval density and environmental variables was assessed by Chi-square tests. Totally, 19,840 larvae from three genera and 16 species were collected and identified. Anopheles maculipennis s.l. and Culex pipiens were the dominant species and collected with the highest density in plain areas. The highest number of larvae were collected from natural habitats (60.34%), including; river edge, marsh, pit and wetlands; with temporary and stagnant water, expanse of 0-5 m, depth of 1-25 cm, without plant, shadow-sun, muddy floor, turbid water, temperature 20-25°C and in sunny conditions. River edge and rice fields for An. maculipennis s.l and, wetlands and discarded tires for Cx. pipiens were the main larval habitats in the province. Statistical analysis revealed significant relation between occurrence of An. maculipennis s.l., Cx. pipiens, Culex torrentium, Culex mimeticus and Cs. annulata with each of the environmental variables (P < 0.001). These findings are essential in expanding our knowledge of the vectors ecology specially the type of habitat preference and will be beneficial in larval control programs.

Correlation between mosquito larval density and their habitat physicochemical characteristics in Mazandaran Province, northern Iran

“…Compatibility of Cx . pipiens to different types of oviposition sites in the vicinity of human places with various degrees of physicochemical factors (especially degree of organic contamination, for example, ammonium ion) and suitable vegetation can probably be important in their interspecific interactions and justify its wide distribution in different counties of the province [ 16 , 39 – 41 ].…”

“…Therefore other factors can be effective in predicting larval density in different areas [ 15 ]. For example, the vegetation of mosquito larval habitats is considered as an important factor in the process of egg-laying and density of mosquito larvae [ 16 ]. Tall emergent aquatic plants can cover the surface and decrease mosquito larval density by acting as a barrier for egg-laying female.…”

Seasonal Activity of Adult Mosquitoes (Diptera: Culicidae) in a Focus of Dirofilariasis and West Nile Infection in Northern Iran

“…A large amount of available data on mosquitoes in Iran is based on collections and ecology of larvae (27, 36–40 and many other references cited by aforementioned articles). Different methods of collecting adult mosquitoes, such as using light traps, aspirators, pit shelters and total catch (Pyrethrum space spray), have been used mostly in relation to anopheline vectors of malarial protozoa (41–47).…”

Monthly Population Fluctuations and Abundance Index (SISA) of Mosquitoes (Diptera: Culicidae), as Potential Bridge Vectors of Pathogens to Humans and Animals in Mazandaran Province, Northern Iran

“…Based on the results of a study in India, it is considered to be predominantly exophilic and normally zoophilic [53]. It was recorded to be the most abundant species in numerous studies in Iran, without reporting any SISA/ISA index [32,33,43,54].…”

“…There were little published data on the seasonal abundance of mosquitoes in Iran [29][30][31]. Up to now, fauna, checklist, physicochemical factor of larval habitats, co-occurrence, association, a nity and biodiversity of mosquitoes have been studied in Mazandaran Province [10,[32][33][34], however, there is no recent comprehensive study on the seasonal activity of mosquitoes in the province. Therefore, this study was conducted to evaluate the monthly dynamics of the mosquito populations and their relation to climatic factors in Mazandaran Province.…”