The cotton whitefly, Bemisia tabaci Gen. (Hem., Aleyrodidae), is a key pest of many vegetables. Entomopathogenic fungi are promising microbial control agents against B. tabaci, but limited information is available concerning indigenous Iranian isolates. In this study, three isolates of Akanthomyces lecanii (PAL6, PAL7, and PAL8) and one isolate of A. muscarius (AGM5) were obtained from citrus hemipteran pests, Pulvinaria aurantii Cock. and Aphis gossypii Glover, in Mazandaran province, northern Iran. The isolates were then morphologically and molecularly identified. The efficacies of five different agar media for vegetative growth and conidiation of each isolate were determined. Potato dextrose agar was the medium on which the fungal mycelia developed at a relatively high rate. However, the highest rate of conidiation was found on Sabouraud dextrose agar. To determine the effects of the isolates on B. tabaci, a dose–response bioassay was carried out to estimate lethal concentration (LC50) and lethal time (LT50) values of each fungal isolate to second instar nymphs. The mean LC50 values of A. lecanii isolates ranged from 4.22 × 106 to 7.35 × 1013 conidia ml−1 at 5 to 7 days after the treatment. For A. muscarius, the values varied from 9.2 × 104 to 8.7 × 1010 conidia ml−1 at 5 to 7 days after the treatment. The lowest and the highest mean LC50 values were observed for A. mucarius (AGM5) and A. lecanii (isolate PAL6), respectively. The mean LT50 values of A. lecanii and A. muscarius isolates were 7.1–9.0 and 4.9–7.2 days, respectively. The LT50 values of A. muscarius were significantly lower than the other isolates. Overall, all isolates, especially A. muscarius (AGM5), exhibited appropriate potential as a biological control agent against B. tabaci.

中文翻译：

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4种昆虫病原真菌Akanthomyces分离株的形态学和分子鉴定及其对黄瓜烟粉虱的抑制作用

棉花粉虱，烟粉虱Gen. (Hem., Aleyrodidae)，是许多蔬菜的主要害虫。昆虫病原真菌是有前途的微生物控制剂烟粉虱，但有关伊朗本土分离株的信息有限。在这项研究中，三个分离株火棘棘孢(PAL6、PAL7 和 PAL8) 和一种分离的A. muscarius(AGM5) 从柑橘半翅目害虫中获得，栀子花公鸡。和棉蚜格洛弗，伊朗北部马赞达兰省。然后对分离物进行形态和分子鉴定。测定了五种不同琼脂培养基对每种分离物的营养生长和分生孢子的功效。马铃薯葡萄糖琼脂是真菌菌丝体在其上以相对高的速率发育的培养基。然而，在沙氏葡萄糖琼脂上发现了最高的分生孢子率。确定分离物对烟粉虱，进行剂量反应生物测定以估计致死浓度（LC50) 和致死时间 (LT50) 每个真菌分离株对二龄若虫的值。平均 LC50的值A. lecanii分离株范围为 4.22 × 106至 7.35 × 1013分生孢子-1在治疗后 5 至 7 天。为了A. muscarius，值从 9.2 × 104至 8.7 × 1010分生孢子-1在治疗后 5 至 7 天。最低和最高平均 LC50观察到的值A. mucarius(AGM5) 和A. lecanii（分离 PAL6），分别。平均 LT50的值A. lecanii和A. muscarius分离株分别为 7.1-9.0 和 4.9-7.2 天。LT50的值A. muscarius明显低于其他分离株。总体而言，所有分离株，尤其是A. muscarius（AGM5），表现出适当的潜力作为生物控制剂烟粉虱.