Behavioral Responses of Bemisia Tabaci Cryptic Species Med to Three Host Plants and Their Volatiles
Abstract Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is a worldwide pest that damages more than 900 host plant species. The infestation behavior of this pest is affected by the volatile organic compounds (volatiles) of different plants and their growth stage. We investigated the chemical constituents of the volatiles extracted from three plants (Gossypium hirsutum, Abutilon theophrasti and Ricinus communis) at different growth stages (pre-flowering, florescence and fruiting) and their effects on the behavior of adult B. tabaci. The selectivity studies on three plants showed that the B. tabaci preferred piemarker. The olfactometer studies showed that growth periods of the three plants also affected the preference of B. tabaci. Volatiles of piemarker and cotton plant had different levels of attraction to adults during all stages. Volatile substances released by castor at stage of flowering have a repellent effect on B. tabaci. In the plant VS plant combination ,the adults showed the strongest preference to volatiles from before and during anthesis of piemarker, followed by cotton, and then castor. A total of 23, 22 and 18 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 showed that linalool and high concentration of leaf acetate had strong trapping effect on this pest, while 1-nonanal had significant repellent effect at high concentration. This study indicates that different plants and their growth stage affects their attractiveness or repellency to B. tabaci adults which is mediated by plant constitutive and dynamic changes. The compounds obtained by analysis screening can be used as potential attractants or repellents to control Mediterranean (MED) B. tabaci.