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The equine South African pointy vector mosquito, Aedes caballus, poses a significant threat to human health due to its capacity for transmitting arboviruses. Despite favorable climate for its existence in southeast Iran, previous records of this species in the area have indicated very low abundance. This comprehensive field and laboratory study aimed to assess its current adult population status in this region, utilizing a combination of ecological, morphological and molecular techniques. Four distinct types of traps were strategically placed in three fixed and two variable mosquito sampling sites in the southern strip of Sistan and Baluchistan Province. Subsequently, DNA was extracted from trapped mosquitoes and subjected to PCR amplification using the molecular markers COI, ITS2, and ANT. In total, 1734 adult Ae. caballus specimens were collected from rural areas, with the majority being captured by CO2-baited bednet traps. A notable increase in the abundance of this species was observed following rainfall in February. The genetic analysis revealed multiple haplotypes based on COI and ITS2 sequences, with COI gene divergence at 0.89%, and ITS2 sequence divergence at 1.6%. This suggests that previous challenges in morphological identification may have led to misidentifications, with many adults previously classified as Ae. vexans potentially being Ae. caballus. The findings of this study hold significant implications for public health authorities, providing valuable insights for integrated and targeted vector control and disease management efforts., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Nejati et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Due to the effect of synthetic and commercial insecticides on non-target organisms and the resistance of mosquitoes, non-chemical and environmentally friendly methods have become prevalent in recent years. The present study was to isolate entomopathogenic fungi with toxic effects on mosquitoes in natural larval habitats., Methods: Larvae of mosquitoes were collected from Central, Qamsar, Niasar, and Barzok Districts in Kashan County, Central Iran by standard dipping method, from April to late December 2019. Dead larvae, live larvae showing signs of infection, and larvae and pupae with a white coating of fungal mycelium on the outer surface of their bodies were isolated from the rest of the larvae and sterilized with 10% sodium hypochlorite for 2 min, then washed twice with distilled water and transferred to potato-dextrose-agar (PDA) and water-agar (WA) media and incubated at 25 ± 2 °C for 3-4 days. Larvae and fungi were identified morphologically based on identification keys., Results: A total of 9789 larvae were collected from urban and rural areas in Kashan County. Thirteen species were identified which were recognized to belong to three genera, including Anopheles (7.89%), Culiseta (17.42%) and Culex (74.69%). A total of 105 larvae, including Anopheles superpictus sensu lato (s.l), Anopheles maculipennis s.l., Culex deserticola, Culex perexiguus, and Culiseta longiareolata were found to be infected by Nattrassia mangiferae, Aspergillus niger, Aspergillus fumigatus, Trichoderma spp., and Penicillium spp. Of these, Penicillium spp. was the most abundant fungus isolated and identified from the larval habitats, while An. superpictus s.l. was the most infected mosquito species., Conclusions: Based on the observations and results obtained of the study, isolated fungi had the potential efficacy for pathogenicity on mosquito larvae. It is suggested that their effects on mosquito larvae should be investigated in the laboratory. The most important point, however, is the proper way of exploiting these biocontrol agents to maximize their effect on reducing the population of vector mosquito larvae without any negative effect on non-target organisms., (© 2021. The Author(s).)

Background: Different mosquito-borne pathogens are circulating in Iran including Sindbis virus, West Nile virus, filarioid worms and malaria parasites. However, the local transmission cycles of these pathogenic agents are poorly understood, especially because ecological data on vector species are scarce and there is limited knowledge about the host range; this understanding could help to direct species-specific vector control measurements or to prioritize research., Methods: In the summers of 2015 and 2016, blood-fed mosquitoes were collected at 13 trapping sites on the coast of the Caspian Sea in northern Iran and at an additional trapping site in western Iran. Mosquitoes were generally collected with either a Biogents Sentinel trap or a Heavy Duty Encephalitis Vector Survey trap installed outside. A handheld aspirator was used at the trapping site in western Iran, in addition to a few samplings around the other trapping sites. On average, eight trapping periods were conducted per trapping site. The sources of blood meals were identified using a DNA barcoding approach targeting the cytochrome b or 16S rRNA gene fragment., Results: The source of blood meals for 580 blood-fed mosquito specimens of 20 different taxa were determined, resulting in the identification of 13 different host species (9 mammals including humans, 3 birds and 1 reptile), whereby no mixed blood meals were detected. Five mosquito species represented more than 85.8% of all collected blood-fed specimens: Culex pipiens pipiens form pipiens (305 specimens, 55.7% of all mosquito specimens), Cx. theileri (60, 10.9%), Cx. sitiens (51, 9.3%), Cx. perexiguus (29, 5.3%) and Anopheles superpictus (25, 4.6%). The most commonly detected hosts of the four most abundant mosquito species were humans (Homo sapiens; 224 mosquito specimens, 40.9% of all mosquito specimens), cattle (Bos taurus; 171, 31.2%) and ducks (Anas spp.; 75, 13.7%). These four mosquito species had similar host-feeding patterns. The only exceptions were a relatively high proportion of birds for Cx. pipiens pipiens f. pipiens (23.2% of detected blood meal sources) and a high proportion of non-human mammals for Cx. theileri (73.4%). Trapping month, surrounding area, or trapping method had no statistically significant impact on the observed host-feeding patterns of Cx. pipiens pipiens f. pipiens., Conclusions: Due to the diverse and overlapping host-feeding patterns, several mosquito species must be considered as potential enzootic and bridge vectors for diverse mosquito-borne pathogens in Iran. Most species can potentially transmit pathogens between mammals as well as between mammals and birds, which might be the result of a similar host selection or a high dependence on the host availability.

Anopheles subpictus Grassi is considered a secondary malaria vector in parts of Asia. The current study determined some ecological and bionomical characteristics of this species in southeastern Iran. The temporal patterns of abundance, resting behavior, blood feeding activity, host selection, adult susceptibility to insecticides and larval habitats were investigated. Most adults were collected by pyrethrum space-spray collection, followed by pit shelters and outlet window traps, respectively. The abdominal condition index of gravid to blood fed females resting outdoors was more than one, thereby showing exophilic resting behavior. Only 25% of engorged females tested positive for human blood, even though most of the samples were collected from houses. The host seeking activity of An. subpictus was bimodal with peaks at 22-2300 h and 03-0400 h. Also, the relative abundance showed peaks in March and December. The results of susceptibility tests showed a resistance of field strains to DDT. Future studies are needed to investigate the possible role of this species in malaria transmission in southeastern Iran.