Malathion and Propoxur Resistance in Turkish Populations of the Anopheles maculipennis Meigen (Diptera: Culicidae) and Relation to the Insensitive Acetylcholinesterase

OBJECTIVE: The objective of this study was to evaluate insecticide resistance related to acetylcholinesterase (AChE) sensitivity and annual changes in An. maculipennis from six different populations. METHODS: Larvae and adult samples of An. maculipennis were collected from six different localities (Birecik, Beysehir, Cankiri, Avariz, Tatarkoy, Derekoy) in Turkey. Insecticide susceptibility against malathion and propoxur was determined. AChE and insensitive AChE levels were measured individually. RESULTS: All Anopheles maculipennis population mortality rates were placed in the suspected resistance category for malathion and propoxur in 2007. While Thrace region populations (Avariz, Tatarkoy, Derekoy) were placed in the surveillance category in 2008, the Birecik, Beysehir, and Cankiri populations were identified in the resistance category. According to the biochemical assay, AChE inhibition rates were high in 2007 and decreased in 2008, except in Derekoy. CONCLUSION: Our results revealed that insecticide resistance against malathion and propoxur increased from 2007 to 2008. Biochemical assay results showed that the AChE insensitivity for 2 test years and insensitive AChE frequency had increased annually. Our results also showed that extensive usage of organophosphate and carbamate for pest control in agriculture is a key factor for malathion and propoxur resistance in all tested populations rather than direct usage of mosquito control.