It has a wide host range, feeding on grasses, field and forage crops, vegetables, and fruit crops. Western flower thrips migrate into olives after adjoining grasses dry up in spring, causing serious damage to fruit. Ascolano is most susceptible, although other cultivars can be damaged. Western flower thrips are 0.05 inch long, slender, amber yellow, with a bright orange thorax. Damaged fruit is culled prior to processing.
Olive groves adjoining drying grain fields are most susceptible to damage.
There is no current California registration for any chemical treatment. If a special local need registration is approved, treatments should be made at full bloom if thrips are migrating to olives and their presence has been noted in the bloom. The Regents of the University of California. All rights reserved. For noncommercial purposes only, any Web site may link directly to this page or photo file.