Different larval habitats and insecticide resistance frequency of Anopheles sinensis in Ganghwagun, Incheon, South Korea

Monitoring the ecology and insecticide resistance of Anopheles mosquitoes, which transmit malaria, is important for developing effective malaria control strategies. This study characterized the present larval breeding habitats of Anopheles mosquitoes in South Korea; additionally, we investigated the frequency of insecticide resistance in Anopheles in the Ganghwagun, Gyeonggi-do province, near the demilitarized zone (DMZ), of South Korea. While larvae of An. sineroides and An. lindesayi were found near forests in Naega-myeon and Kukhwa-ri, respectively, An. sinensis larvae were predominantly found in irrigation canal near rice fields in Seonhaeng-ri, alongside An. belenrae. Seven genotypes of knockdown resistant (kdr) allele in the voltage-gated sodium channel of An. sinensis were introduced, revealing a new kdr genotype. Notably, almost all of An. sinensis captured in this study was shown mutant genotypes with homozygous or heterozygous resistant alleles of acetylcholinesterase (ace-1). Moreover, the predominant presence of mosquitoes harboring mutations in more than one insecticidal target was observed in An. sinensis. In addition, An. belenrae was identified to possess kdr and ace-1 mutation. Taken together, our findings revealed the multiple insecticide resistance of An. sinensis, with larval habitat near the DMZ of South Korea, 2024.