Universidade Federal do Acre, Programa de Pós-graduação em Ciência, Inovação e Tecnologia para Amazônia, Rio Branco, AC, Brasil.
Universidade Federal do Acre, Centro de Ciências da Saúde e do Desporto, Rio Branco, AC, Brasil.
Braz J Biol. 2023 Oct 27;83:e274954. doi: 10.1590/1519-6984.274954. eCollection 2023.
Aedes aegypti L. (Diptera: Culicidae) is the main transmitter of pathogens that cause human diseases, including dengue, chikungunya, zika and yellow fever. Faced with this problem, this study aims to select fungi with entomopathogenic potential against Ae. aegypti and develop formulations that optimize the control action of entomopathogenic fungi in the semi-field condition. 23 fungal strains native from Amazon were inoculated in Potato-Dextrose-Agar (PDA) culture medium for 14 days and then transferred by scraping to tubes containing 0.9% NaCl solution. To obtain the larvae, eggs were collected using traps in peridomestic environments for 7 days. 20 larvae of Ae. aegypti in 125 mL erlenmeyers containing 20 mL of conidial suspension at a concentration of 1x106 conidia/mL for initial selection and 1×104, 1×105, 1×106 and 1×107 conidia/mL for determination of LC50. Mortality was checked every 24 h for 5 days. The three fungi with the best virulence rates were identified using molecular techniques. The compatibility between fungi at a concentration of 1×106 conidia/mL and oily adjuvants, mineral oil and vegetable oil (andiroba, chestnut and copaiba) at concentrations of 0.1, 0.5 and 1% was evaluated. The germination capacity of 100 conidia per treatment was evaluated after incubation at 28 ºC for 24 h. To evaluate the entomopathogenic potential of the fungal formulations, conidial suspensions (1×106 conidia/mL) were added with 0.1% mineral and vegetable oil. The treatments were submitted to laboratory and semi-field conditions and mortality was verified every 24 h for 5 days. Beauveria sp. (4,458) (LC50 = 8.66× 103), Metarhizium anisopliae (4,420) (LC50 = 5.48×104) and M. anisopliae (4,910) (LC50 = 1.13×105) were significantly more effective in the larval control of Ae. aegypti, in relation to the other fungal morphospecies evaluated. Mineral oil was better compatible in all treatments evaluated. Beauveria sp. (4,458) was considerably less virulent under semi-field conditions. M. anisopliae (4,910) formulated with mineral oil increased larval mortality to 100% on the 4th day in the laboratory and on the 5th day in the semi-field. Fungal formulations developed from native Amazonian isolates represent a promising tool for the development of strategies to control Ae. aegypti.
埃及伊蚊（双翅目：蚊科）是引起人类疾病的病原体的主要传播媒介，包括登革热、基孔肯雅热、寨卡和黄热病。面对这个问题，本研究旨在选择具有杀蚊潜力的真菌来对抗埃及伊蚊，并开发优化半野外条件下杀蚊真菌控制作用的配方。23 株来自亚马逊的真菌菌株接种在马铃薯葡萄糖琼脂（PDA）培养基中 14 天，然后用刮刀转移到含有 0.9%NaCl 溶液的试管中。为了获得幼虫，在 7 天内使用陷阱在家庭环境周围收集卵。将 20 只埃及伊蚊幼虫放入含有 20 mL 分生孢子悬浮液的 125 mL 鹅颈瓶中，初始浓度为 1x106 个分生孢子/mL，LC50 测定浓度为 1×104、1×105、1×106 和 1×107 个分生孢子/mL。每 24 小时检查一次死亡率，持续 5 天。使用分子技术鉴定具有最佳毒力的三种真菌。评估了浓度为 1×106 个分生孢子/mL 的真菌与矿物油和植物油（andiroba、板栗和 copaiba）在 0.1、0.5 和 1%浓度下的兼容性。在 28°C 孵育 24 小时后，评估了每处理 100 个分生孢子的萌发能力。为了评估真菌配方的杀蚊潜力，将分生孢子悬浮液（1×106 个分生孢子/mL）添加 0.1%矿物油和植物油。将处理品置于实验室和半野外条件下，每 24 小时检查一次死亡率，持续 5 天。球孢白僵菌（4,458）（LC50=8.66×103）、金龟子绿僵菌（4,420）（LC50=5.48×104）和金龟子绿僵菌（4,910）（LC50=1.13×105）对埃及伊蚊幼虫的控制效果明显优于其他评估的真菌形态。在所有评估的处理中，矿物油的兼容性更好。球孢白僵菌（4,458）在半野外条件下的毒力明显降低。用矿物油配制的金龟子绿僵菌（4,910）在实验室第 4 天和半野外第 5 天使幼虫死亡率达到 100%。从亚马逊本地分离物开发的真菌配方代表了开发控制埃及伊蚊策略的有前途的工具。
