Department of Medical Entomology & Vector Control, School of Public Health, Tehran University of Medical Sciences, P.O. Box 6446-14155, Tehran, Iran.
Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extention Organization (AREEO), Tehran, Iran.
Malar J. 2021 Oct 9;20(1):393. doi: 10.1186/s12936-021-03927-4.
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.
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.
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.
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.
由于合成杀虫剂和商业杀虫剂对非靶标生物的影响以及蚊子的抗药性，近年来，非化学和环保方法变得流行起来。本研究旨在从自然幼虫栖息地中分离对蚊子具有毒性的昆虫病原真菌。
2019 年 4 月至 12 月下旬，采用标准浸渍法从伊朗中部卡尚县的中央、Qamsar、Niasar 和 Barzok 区采集蚊子幼虫。从其余幼虫中分离出死亡的幼虫、表现出感染迹象的活幼虫以及幼虫和蛹，其身体外表面有真菌菌丝的白色涂层，并用 10%次氯酸钠消毒 2 分钟，然后用蒸馏水洗涤两次，然后转移到土豆-葡萄糖-琼脂（PDA）和水琼脂（WA）培养基中，并在 25±2°C 下孵育 3-4 天。根据鉴定手册对幼虫和真菌进行形态学鉴定。
从卡尚县城乡共采集了 9789 只幼虫。鉴定出 13 个种，属于 3 个属，包括 Anopheles（7.89%）、Culiseta（17.42%）和 Culex（74.69%）。共发现 105 只幼虫，包括 Anopheles superpictus s.l、Anopheles maculipennis s.l、Culex deserticola、Culex perexiguus 和 Culiseta longiareolata 被 Nattrassia mangiferae、黑曲霉、烟曲霉、木霉属和青霉属感染。其中，青霉属是从幼虫栖息地中分离和鉴定出的最丰富的真菌，而 An. superpictus s.l. 是感染最严重的蚊子种类。
根据研究的观察和结果，分离出的真菌对蚊子幼虫具有潜在的致病性。建议在实验室中研究它们对蚊子幼虫的影响。然而，最重要的是要以适当的方式利用这些生物防治剂，最大限度地发挥它们减少媒介蚊子幼虫数量的作用，而不对非靶标生物产生任何负面影响。
