Determination of Insecticide Resistance in Western Flower Thrips [Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)] Causing Problems in Carnation Cultivation

Abstract

The fact that Frankliniella occidentalis (Thysanoptera: Thripidae) completes its life cycle in a short time reveals the need for continuous pest control. Therefore, pest resistance may occur with the intensive use of chemicals by the growers. In this context, the current sensitivity of F. occidentalis to registered insecticides for carnation (methiocarb, formetanate hydrochloride), registered insecticides for vegetables (azadirachtin, malathion, and spinosad), and unapproved insecticides used extensively by growers needs to be determined. Moreover, it is important to test the chemicals (for example, pyridalyl) used against other pests whose spray period is the same as F. occidentalis. In this study, it was aimed to determine the sensitivity levels of F. occidentalis populations taken from the sites of intensive carnation production in Antalya province in 2018-2020 to these chemicals by the leaf dipping method. As a result of the study, resistance against spinosad (11.00-28.60 times), methiocarb (2.10-2.70 times), malathion (2.05-4.21 times), azadirachtin (3.00-7.00 times), formetanate hydrochloride (1.50-2.00 times) and pyridalyl (2.75-3.89 times) were determined. Given the high resistance to spinosad observed in the study, trials involving the combination of spinosad and formetanate hydrochloride were initiated as a strategy for managing resistance. The resistance against spinosad + formetanate hydrochloride was determined between 4.35 and 9.09 times. Our results suggest that resistance level can be reduced by using resistance management methods such as the use of mixed chemicals, although resistance was detected in all five locations against all active substances.