This pest report supersedes the pest report posted on August 8, 2004. Additions to the report are in red text.
Eastern flower thrips, Frankliniella intonsa (Trybom), are frequently intercepted at the Canadian/Washington border from shipments of cut flowers. From August through October 2003, surveys in Washington State revealed F. intonsa (Trybom) widespread on weed species, fruit, flowers, and nursery stock. Shortly after the detections in Washington State, fall surveys in nurseries in Oregon were positive for the thrips. Cut flowers from Canada, which are the most common pathway of dispersal, were removed from the “line release” system and were subject to inspection as of October 8, 2003.
Subsequently, all States were asked to check their insect collections for specimens of F. intonsa which in certain forms can be confused with the native Western flower thrips Frankliniella occidentalis Pergande. Furthermore, States were asked to report positive and negative results from the survey of collections to the National Agricultural Pest Information System database so that PPQ could determine the extent of the U.S. distribution. The information was needed to determine whether or not to continue quarantine actions for this pest. Pending determination, F. intonsa continued as a regulated pest. Results have not yet been obtained; and at this time F. intonsa has been reported only from Washington and Oregon.
Official control is not planned for F. intonsa. Canadian officials report the existence of an isolated population of F. intonsa in cut flower production sites adjacent to the U.S. border. The Canadian Government has no plans to control this pest. Furthermore, viruses vectored by F. intonsa are more effectively vectored by endemic species of thrips, including Western flower thrips.
Since F. intonsa is widespread in the Pacific Northwest, not under official, and is less efficient in vectoring certain diseases than a closely related native species no interstate or international quarantine action is required when this pest is found infesting imported commodities presented at ports of entry for USDA inspection.
However, as with all plant pests not specifically deregulated through publication in the Federal Register, intentional importation or interstate movement of F. intonsa will continue to require a PPQ Plant Pest Permit.