Open AccessInsecticide resistance and molecular characterization of knockdown resistance ( kdr ) in Culex quinquefasciatus mosquitoes in Sri Lanka
Author(s) -
Chandrasiri P.K. Geethika K.,
Fernando Sachini D.,
De Silva B.G.D. Nissanka K.
Publication year - 2020
Publication title -
journal of vector ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.688
H-Index - 51
eISSN - 1948-7134
pISSN - 1081-1710
DOI - 10.1111/jvec.12391
Subject(s) - biology , sri lanka , culex quinquefasciatus , insecticide resistance , gene knockdown , culex , knockdown resistance , toxicology , genetics , pesticide , gene , permethrin , ecology , larva , south asia , ancient history , aedes aegypti , cyfluthrin , history
ABSTRACT Resistance to pyrethroids (PY) and organophosphate (OP) insecticides is widespread among populations of Culex quinquefasciatus , the major vector of lymphatic filariasis (LF). The present study was designed to detect the L1014F kdr (knockdown resistant) mutation among Cx. quinquefasciatus populations in the filarial belt of Sri Lanka. Mosquitoes were reared from field‐caught larvae from seven localities where LF is endemic. Susceptibility status of Cx. quinquefasciatus to adulticides, 0.05% deltamethrin, 0.75% permethrin, 5% malathion, and the larvicide temephos was determined using the standard WHO susceptibility tests. A fragment of vgsc gene was amplified and sequenced to identify the responsible kdr mutations. The susceptibility test results revealed less than 90% mortalities for 0.05% deltamethrin, and 0.75% permethrin and temephos. For 5% malathion, all study sites except Maharagama revealed greater than 90% mortality. The L1014F kdr mutation was observed in all studied populations. Although the overall microfilaria rate is less than 1% in the country, there is a high risk of re‐emergence of LF in Sri Lanka due to abundant Cx. quinquefasciatus mosquitoes, increased resistant status to currently used insecticides, imported LF cases, higher rates of microfilaria among neighboring countries, and the advancement of tourism.