Diel flight activity of Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) in greenhouse crops

Abstract: Diel flight activity of Frankliniella occidentalis (Thysanoptera: Thripidae) was evaluated inside sweet pepper plastic greenhouses, in terms of periodicity and vertical distribution of individuals. Results from this study exclude the possibility that thrips move inside the crop during the middle of the day for escaping high temperature and/or light intensity. Similarly, there was no evidence of a possible concentration of thrips just below the greenhouse ceiling, due to upward hot air currents, nor evidence that the two flight peaks (mid morning and mid afternoon) shown by the thrips are caused solely by a bimodal adult emergence from the soil or caused by in- and outbound movements of these insects during different hours of the day or even by the type of traps used to register thrips flight activity.