Behavioral Responses of Bemisia tabaci Mediterranean Cryptic Species to Three Host Plants and Their Volatiles

Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is a worldwide pest that damages over 900 host plant species. The volatile organic compounds (volatiles) of contrasting plants, as well as their growth stage, influence this pest's infestation behavior. The chemical contents of volatiles isolated from three plants (Gossypium hirsutum, Abutilon theophrasti, and Ricinus communis) during various growth phases (pre-flowering, fluorescence, and fruiting) were examined, as well as their influence on the behavior of adult B. tabaci. The olfactometer studies demonstrated that growth periods of the three plants affected the preference of B. tabaci. Volatiles of piemarker and cotton plants had dissimilar levels of attraction to adults during all stages. Volatile substances released by the castor at the stage of flowering had repellent effect on B. tabaci. In the plant versus plant combination, piemarker volatiles before and during anthesis were most preferred by adults, followed by cotton and then castor. A total of 24, 24, and 20 compounds were detected from volatiles of piemarker, cotton, and castor, respectively, and proportions among the compounds changed during different stages of plant development. The olfactory responses of B. tabaci to volatile compounds presented that linalool and high concentration of (Z)-3-hexenyl acetate had a strong trapping effect on this pest, while nonanal had a significant repellent effect at high concentration. This study indicates that distinct plants and their growth stage affect their attractiveness or repellency to B.tabaci adults, which are mediated by changing plant volatiles. These compounds obtained by analysis screening can be adopted as potential attractants or repellents to control Mediterranean (MED) B. tabaci.