Diptera pests control in onions.
Onions in Croatia are usually attacked by four species of Diptera - Napomyza gymnostoma, Delia antiqua, Chromatomyia horticola and Liriomyza cepae. This article discusses the results of a 3-year field trial (1999 to 2001) on the control of these Diptera species. The efficacies of different insecticides (dimethoate, imidacloprid, chlorpyrifos-ethyl, chlorpyrifos-methyl and phoxim) applied with different application techniques (spraying, irrigation, bulb dipping and granule application) for Diptera control on onions were evaluated. No phytotoxicity symptoms were observed after insecticide application. Successful Diptera pest control on onion was achieved after dipping onion bulbs in dimethoate (average efficacy 100%) and imidacloprid (85.51-100%), spraying with dimethoate (77.8-100%) and imidacloprid (52.37-92.75%), or irrigating plants with the before mentioned systemic insecticides (77.8-100% with dimethoate and 46.62-91.65% with imidacloprid).