Investigating insecticide resistance, kdr mutation, and morphology of the coastal mosquito Aedes (Ochlerotatus) zammitii (Theobald, 1903) (Diptera: Culicidae)

Abstract

This study aimed to assess the insecticide resistance levels and investigate the presence of the kdr mutation in Aedes (Ochlerotatus) zammitii (Theobald, 1903) (Diptera: Culicidae) mosquito populations collected from various locations within the Aegean region of Türkiye. Additionally, the study explored the morphological details of Ae. zammitii eggs and adults by using scanning electron microscopy (SEM). Mosquitoes were collected from their natural rocky breeding habitats from several provinces from April to October 2023 using larvae scoops at different aquatic stages. Emerged adult mosquitoes were identified using both taxonomic keys and molecular methods. The obtained images from SEM analysis revealed unique surface features that could potentially be used to identify the species. The susceptibility of adult Ae. zammitii to six insecticides, namely DDT (4%), fenitrothion (1%), bendiocarb (0.1%), deltamethrin (0.05%), permethrin (0.75%) and malathion (5%), was determined using the World Health Organization (WHO) susceptibility test. Results indicated that the mosquitoes exhibited varied possible resistance to the different pesticides tested. Mortality rates ranged between 72%-96%. This research confirmed the presence of kdr mutation associated with pyrethroid resistance in Ae. zammitii. The frequency of L1014F mutation ranged between 55 and 70% with the highest frequency determined in Antalya-Kaş population, followed by Karaburun and Çandarlı in İzmir. These findings significantly contribute to the understanding of insecticide resistance in Ae. zammitii, paving the way for developing effective mosquito control strategies in the Aegean region.