The whitefly, Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae), is one of the most damaging pests in field crops as well as in greenhouses. The present study aimed to evaluate the in vitro pathogenicity of 2 fungus strains of Beauveria bassiana (BB-72 and BB-252) and one strain of Lecanicillium lecanii (V-2) against the whitefly (B. tabaci) at 4 different temperature degrees 20, 24, 28, and 32 °C, using a spray method. Three different bioassays were carried out comprised of conidial concentrations and filtrate of fungal strains, BB-72, BB-252 and V-2, and their binary combinations. The 1.5 ml of fungal filtrate was used in filtrate bioassay for each strain of fungus. Three different concentrations (1 × 106, 1 × 107, and 1 × 108 conidia ml−1) were used in conidial bioassay for each strain of fungus, whereas in bioassay for binary combination (1 ml conidia + 1 ml filtrate) of BB-72 × BB-72, BB-252 × BB-252, and V2 × V2 were used for these strains of fungus. According to the outcomes, the maximum mortality against whiteflies was observed on 12th day post-treatment. In conidial bioassay, the maximum mortality of B. tabaci was observed in BB-72 isolate (84%), BB-252 isolate (77%), and V-2 isolate (67%) at the highest concentration (1 × 108 conidia ml−1) at 24 °C, and minimum mortality was recorded in BB-72 isolate (33%), BB-252 isolate (29%), and V-2 isolate (19%) at the lowest concentration 1 × 106 conidia ml−1 at 32 °C on 12th day post-treatment. Infiltrate bioassay, BB-72 isolate exhibited maximum mortality (92%) at 24 °C, and V-2 isolate showed minimum mortality (34%) at 32 °C on 12th day post-treatment. Furthermore, in binary combination bioassay, the highest whitefly mortality was recorded in BB-72 × BB-72 isolate (87%), BB-252 × BB-252 isolate (73%), and V2 × V2 isolate (65%) at 24 °C and the lowest mortality in BB-72 × BB-72 isolate (57%), BB-252 × BB-252 isolate (50%), and V2 × V2 isolate (39%) at 32 °C on 12th day post-treatment. In all bioassays, the BB-72 isolate was the utmost virulent, and application of its filtrate was found to be the most impressive against B. tabaci.

中文翻译：

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球孢白僵菌和Lecanicillium lecanii真菌在不同温度下对粉虱Bemisia tabaci（Genn。）的体外致病性（半翅目：无翅目）

烟粉虱，烟粉虱（Bemisia tabaci，Genn。）（半翅目：Aleyrodidae），是田间作物和温室中危害最大的害虫之一。本研究旨在评估4种不同温度下2种球孢白僵菌（BB-72和BB-252）和1种Lecanicillium lecanii（V-2）对粉虱（B. tabaci）的体外致病性。 20、24、28和32°C，采用喷涂方法。进行了三种不同的生物测定，包括真菌菌株BB-72，BB-252和V-2的分生孢子浓度和滤液，以及它们的二元组合。将1.5ml的真菌滤液用于每种真菌菌株的滤液生物测定中。对于每种真菌菌株，在分生孢子生物测定中使用了三种不同的浓度（1×106、1×107和1×108分生孢子ml-1），而在这些真菌菌株的二元组合生物测定（1 ml分生孢子+ 1 ml滤液）中，使用了BB-72×BB-72，BB-252×BB-252和V2×V2。根据结果​​，在治疗后第12天观察到对粉虱的最大死亡率。在分生孢子生物测定中，在最高浓度（1×108分生孢子）下，BB-72分离株（84％），BB-252分离株（77％）和V-2分离株（67％）观察到烟粉虱的最大死亡率。 ml-1）在24°C时，在最低浓度1×106分生孢子的BB-72分离株（33％），BB-252分离株（29％）和V-2分离株（19％）中记录的最低死亡率处理后第12天，在32°C下，ml-1。浸润生物测定法，在处理后第12天，BB-72分离株在24°C时表现出最高死亡率（92％），而V-2分离株在32°C时表现出最低死亡率（34％）。此外，在二元组合生物测定中，在24°C时，BB-72×BB-72分离株（87％），BB-252×BB-252分离株（73％）和V2×V2分离株（65％）的粉虱死亡率最高。 C后第12天，BB-72×BB-72分离株（57％），BB-252×BB-252分离株（50％）和V2×V2分离株（39％）的死亡率最低。治疗。在所有生物测定中，BB-72分离物都是最强毒力的，其滤液的应用被发现对烟曲霉的影响最大。