Funa Study and Larval Habitats of Culicidae in Shushtar County, Southwest Iran

Background and purpose: Culicidae plays a crucial role in the spread of diseases like Malaria and arboviral diseases such as Japanese Encephalitis, Zika virus, Chikungunya, Dengue fever, Yellow fever, and West Nile fever. Different mosquito species have different abundance and distribution due to a variety of factors, such as physicochemical factors, weather conditions, vegetation, and human activities. The characteristics of larval habitats are among the factors affecting the population, and diversity, and determining the preferred breeding places of the species. For this reason, a study was conducted to examine the species diversity of Culicidae and their larval habitats in Shushtar County. Materials and methods: This cross-sectional study was conducted in Shushtar County from the central, Mian Ab and Shuaibiya districts, 2021. Larvae were collected from the breeding places in the sampling areas including Noormohammadi, Konarpir, Saheli, Abu Gerva, and Pirdalu by using the dipping technique in spring and summer and kept in lactophenol solution. Then, a microscopic slide was prepared from the samples using licidophor, which were identified with valid diagnostic keys. Characteristics of larval habitat such as habitat type, water condition, vegetation, substrate type, water quality, and light condition were also recorded. To analyze the data and determine the relationship between the frequency and characteristics of larval habitats, SPSS version 16 software and a chi-square statistical test were used. Qualitative variables were also reported as numbers (percentages). Abundance and distribution maps of samples were prepared using ArcGIS software version 10.5. Results: In this study, a total of 527 larvae were identified, including five species of Anopheles stephensi, Culex pusillus, and Cx. sinaiticus, Cx. theileri and, Cx. Perexiguus. Anopheles stephensi with the lowest frequency (8.48%) was reported only from the Saheli area. This species was collected from temporary, stationary, without vegetation, mud substrate, cloudy water, sunny, and natural habitats. Culex theileri, one of the important vectors of arboviral diseases, was observed in temporary and natural habitats, stagnant waters without vegetation, and cloudy and sunny waters habitates. Culex pusillus was the only species observed in Pirdalo and Abu Gerva. By examining the larval habitats of Culicidae in Shushtar County, Cx. pusillus was the most abundant collected species, from temporary habitat (82.7%), stagnant waters (73.6%), mud substrate (100%), turbid waters (78.6%), natural (95%), and sunny (82.7%). Also, the abundance of collected larvae in temporary habitats, stagnant waters, in areas with vegetation, and mud substrate was high. Besides, it was more abundant in turbid waters and sunny areas, and these differences were statistically significant (P