BIOLOGY AND ECOLOGY OF THE WESTERN FLOWER THRIPS (THYSANOPTERA: THRIPIDAE): THE MAKING OF A PEST

In the past 30 years, western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), has become one of the most important agricultural pests worldwide. Certain biological attributes of this insect predispose it to be a direct post across a wide range of crops. In addition to the direct damage it can cause, this species is an efficient vector of Tomato spotted wilt virus and other Tospoviruses. This review addresses questions regarding the biological and ecological attributes of western flower thrips that have enabled it to become a significant pest and make it so difficult to manage. These important life history traits include western flower thrips polyphagy and a tendency to reside and feed in concealed areas of flowers and fruits. Consequently, large populations can develop and disperse into a wide range of crops. The larvae and adults feed in a similar manner and can share the same host plant resources. The relatively short generation time and haplodiploid sex determination also contribute to the pest status of this species. These life history traits interact in complex ways to make western flower thrips one of the most significant and difficult to manage pests in the world.