Author:
Keerio Azhar Uddin,Nazir Talha,Abdulle Yusuf Ali,Jatoi Ghulam Hussain,Gadhi Muswar Ali,Anwar Tauqir,Sokea Tum,Qiu Dewen
Abstract
AbstractThe 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.
Funder
National Key Research and Development Program of China
Publisher
Springer Science and Business Media LLC
Subject
Insect Science,Plant Science,Agronomy and Crop Science,Ecology