TITLE:
Evaluation of Efficacy of Insecticides and Long-Lasting Insecticidal Nets for Control of Culex quinquefasciatus Say Populations from Northern Nigeria
AUTHORS:
Jamila A. Datti, Muhammad M. Mukhtar, Maimuna T. Usman, Bilkisu I. Abba, Binta G. Kurfi, Sulaiman S. Ibrahim
KEYWORDS:
Culex quinquefasciatus, Metabolic, Resistance, Insecticides, LLINs, PBO, P450s
JOURNAL NAME:
Advances in Entomology,
Vol.10 No.2,
April
28,
2022
ABSTRACT: Information on Culex mosquitoes (vectors of filarial worm and
viral encephalitis) from northern Nigeria is scanty, hindering evidence-based
control. Here, two Culex populations (Kano and Kaduna) were
characterized. Culex quinquefasciatus and Culex pipiens were
found breeding in sympatry, with some hybrid individuals identified. Larval
bioassays revealed high temephos resistance (LC50s = 1.34 mg/mL and
3.01 mg/mL for Kano and Kaduna, respectively). Larvae were more sensitive to α-cypermethrin (LC50s = 0.026
mg/mL and 0.067 mg/mL for Kano and Kaduna). WHO adult tube bioassays revealed
high pyrethroid and DDT resistance, with mortalities of 44.01% ± 6.79%, 35.83%
± 12.58%, 29.69% ± 9.97% and 52.47% ± 4.34% for permethrin, deltamethrin, α-cypermethrin and DDT, respectively.
Highest resistance was observed with bendiocarb (mortality = 13.58% ± 3.98%).
High resistance was obtained with fenitrothion and malathion (mortalities = 21%
± 4.76% and 56.47% ± 8.67%, respectively), while a full susceptibility was
observed with pirimiphos-methyl. Pre-exposure to piperonylbutoxide (PBO)
significantly recovered α-cypermethrin
susceptibility (mortality = 82% ± 5.16%, χ2 = 50.99, p kdr genotype and resistance phenotype.
Sequencing of fragments of the acetylcholinesterase-1 gene detected no
G119S mutation, in malathion-alive and malathion-dead females. These suggest a
preeminent role of metabolic resistance in these Culex populations.