Pest management of Bemisia out of doors

Bemisia (Hemiptera: Homoptera: Aleyrodidae) adults are mobile and may migrate to new fields of susceptible crops causing almost instantaneous outbreaks. Immatures develop on the undersides of leaves, and so are difficult to reach with insecticides. Damage may be caused directly, through soiling of the plants and fruits with honeydew, or through transmission of viral diseases. Different damage relates to different degrees of tolerance for the pest, and the need for different thresholds for its treatment. We still do not know exactly under which conditions parasitoid activity may be sufficient, nor do we know the roles and relative importance of the main predators that occur in the Bemisia-infected cotton fields in Israel. Future studies should emphasize the genetics of the dispersing pest populations, Bemisia-plant interactions, and the role of organisms, both at the same and on other trophic levels.