Susceptibility to common insecticides and detoxifying enzyme activities in Anopheles sundaicus (sensu lato) after cessation of indoor residual spraying of insecticides in the Jaffna Peninsula and its surroundings in northern Sri Lanka

Table 2 Anopheles sundaicus (s.l.) populations with discriminating activities of GST, EST and MO and insensitive target site AChE

District	Enzyme activity profiles	AChE (%)^a			GST^b	EST^c	MO^d
District	Enzyme activity profiles	< 30 [SS]	30–70 [RS]	> 70 [RR]	GST^b	EST^c	MO^d
Jaffna district	% population(a) in different categories and (b-d) with elevated activities	50	35	15	30	0	0
Jaffna district	Mean activity ± SE				0.38 ±0.02	0.04 ±0.002	0.03 ±0.001
Kilinochchi district	% population(a) in different categories and (b-d) with elevated activities	78	17	5	100	0	0
Kilinochchi district	Mean activity ± SE				1.85 ±0.08	0.06 ±0.004	0.003 ±0.001
Pooled data for both districts	% population (a) in different categories and (b-d) with elevated activities	68	23	9	69	0	0
Pooled data for both districts	Mean activity ± SE				1.14 ±0.09	0.06 ±0.004	0.02 ±0.002

Abbreviation: SE standard error of the mean
^aPercent remaining activity of AChEs in individual mosquitoes after Propoxure inhibition in homozygous (SS) sensitive, heterozygous (RS) and homozygous (RR) insensitive populations [24]
^bPercentage of population having glutathione S-transferase (GST) discriminant specific activity above 0.40 μmol/mg/min and mean specific activities
^cPercentage of population having esterase (EST) discriminant specific activity above 0.25 μmol/mg/min and mean specific activities
^dPercentage of population having monooxygenase (MO) levels above the discriminant activity of 0.35 units per mg protein of cytochrome P₄₅₀ and mean specific activities [18, 23]

ISSN: 1756-3305