Behavioral change of Bemisia tabaci and Trialeurodes vaporariorum ( Hemiptera: Aleyrodidae ) infected by Lecanicillium muscarium ( Hypocreales: Cordycipitaceae )

The effects of entomopathogenic fungus Lecanicillium muscarium on feeding and host preference were investigated on Bemisia tabaci (Gennadius) and Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyroidae) using 2aF43 and Mycotal® strains. Feeding activity was monitored up to day five post fungal inoculation using electric penetration graph while host preference was evaluated by choice-test bioassay for 72 h. Our results showed a reduction in the ability of the infected insects to ingest xylem and reach the phloem. Interestingly the two tested fungal strains interfered on different feeding activities. Only 2aF43 reduced cell puncturing in both insects. Pre-inoculation of plants by 2aF43 increased feeding difficulties and searching time of B. tabaci by 74.9% and 40.1%, respectively. Host choice bioassay showed that insects started aborting the fungal-treated leaf disks after 24 h. By the lapse of 72 h, 2aF43 had a repulsion range of 93.3–95.3% which was higher than that of Mycotal® that ranged between 80.0% and 80.7% in both whiteflies. Using choice-test bioassay and electric penetration graph recording, we revealed that L. muscarium effectively repelled whiteflies and deterred them from normal feeding that potentially reduce plant damage.