The effectiveness of a range of insecticides against western flower thrips (Frankliniella occidentalis) (Thysanoptera: Thripidae) on cut flowers

Abstract

Three insecticide spray trials were conducted on field calendulas and chrysanthemums to test the effectiveness of 10 insecticides against western flower thrips (Frankliniella occidentalis). The efficacy of each insecticide was assessed between 1 and 11 days post-spraying. Methamidophos was the most effective insecticide, followed to a lesser extent by dichlorvos, λ-cyhalothrin, fluvalinate, and maldison. Apart from methamidophos, insecticides were generally less than 50% effective at 3 or more days post-spraying. In a separate trial, 5 insecticides were applied as drenches to the soil of pots in which carnations infested with F. occidentalis were grown. The pots were placed in thrips containment cages and adult thrips emerging from the soil were caught on sticky traps. Parathion-methyl and chlorpyrifos reduced thrips emergence from soil by 90-95%.