Table 1 Toxicity of permethrin to Rhipicephalus linnaei larvae obtained from engorged female tick populations collected from 16 provinces in Thailand as determined using the FAO larval packet test and their resistance allele frequencies (RAF) of three SNPs occurred at Domain II and Domain III of voltage-gated sodium channel gene.

From: Mutations in the voltage-gated sodium channel associated with permethrin resistance in Rhipicephalus linnaei populations in Thailand

Locations

GPS coordinates

Number of larvae (No. of replicates)

LC50 (min, max)

Resistance Ratio (95% CI)

Resistance allele frequency (RAF)

Rh. sanguineus as baseline

Rh. linnaei (Lamphun) as baseline

Nonsynnonymous mutation

Synonymous mutation

N (473)

c.190C > A

c.215G > T

c.2134 T > C

N (192)

c.2166 T > C

Rh. sanguineus (temperate lineage)

NA

1825 (3)

0.02 (0, 0.09)

1 (0.87, 1.15)

–

10​

5.00​

5.00​

0

10

0

Ayuthaya

14.359522,100.468141

2219 (4)

0.36 (0.24, 0.49)

22 (14, 35)​

1.73 (0.97, 3.08)

16​

31.30​

34.40​

0

7

50.00

Bangkok (Talingchan)

13.774576,100.454502

2371 (4)

1.29 (1.03, 1.74)

80 (17, 362)​

6.16 (1.26, 30.00)

35​

38.57​

38.57​

4.29​

0

0

Bangkok-2 (Phasichareon)

13.70567,100.436632

1849 (3)

12.00 (5.12, 48.00)

701 (512, 961)​

56.00 (36.00, 87.00)

31​

100**​

71.00

0

29

68.97

Chachoengsao

13.676509,101.829725

1599 (3)

3.57 (2.48, 5.80)

237 (152, 304)​

17.00 (11.00, 27.00)

30​

41.70​

41.70​

21.70​

7

35.71

Chantaburi

12.798287,102.270591

1844 (2)

4.17 (3.15, 5.97)

251 (176, 360)​

20.00 (12.00, 32.00)

21​

19.05​

28.57​

7.14​

21

30.95

Chiangrai

20.095829,99.784805

1365 (3)

0.33 (0.26, 0.42)

20 (12, 35)​

1.60 (0.84, 3.05)

10​

0

20.00​

0

10

50.00

Chumphon

10.641169,99.238549

2129 (3)

5.68 (2.58, 25.00)

342 (249, 471)​

27.00 (17.00, 43.00)

36​

52.78​

25.00​

20.83​

12

37.50

Krabi

8.242495,98.907946

1724 (3)

3.33 (2.14, 6.25)

201 (155, 261)​

16.00 (11.00, 24.00)

10​

0

0

35.00​

10

0

Lamphun

18.182539,99.003476

2283 (4)

0.21 (0.10, 0.35)

13 (9, 18)​

1.00 (0.62, 1.60)

32​

0

6.25​

0

-

-

Lopburi

14.982613,100.923111

2230 (5)

0.60 (0.49, 0.71)

47 (14, 91)​

2.85 (1.07, 7.56)

30​

41.70​

51.70​

11.70​

3

33.33

Nakhonprathom

13.773549,100.313707

1614 (4)

1.92 (1.10, 3.93)

116 (62, 217)​

9.15 (4.52, 18.00)

16​

68.75​

68.75​

31.30​

6

41.67

Petchabun

16.572714,100.98949

1508 (4)

2.80 (1.96, 4.43)

169 (110, 260)​

13.00 (7.83, 23.00)

28​

42.86​

42.86​

35.71​

10

45.00

Phayao

19.201325,100.061173

2470 (4)

1.00 (0.89, 1.14)

61 (0.00, 2.75e + 32)​

4.79 (0, 4.96E + 31)

30​

23.33​

23.33​

16.67​

2

50.00

Prachinburi

14.159327,101.523804

1472 (3)

4.65 (3.26, 7.36)

298 (199, 395)​

22.00 (14.00, 35.00)

35​

42.86​

30.00​

27.14​

-

-

Ratchaburi

13.507891,99.865883

1642 (4)

0.29 (0.15, 0.45)

18 (11, 26)​

1.39 (0.83, 2.31)

30​

0

53.30​

0

2

50.00

Suratthani

9.059651,99.256014

2710 (5)

0.52 (0.36, 0.72)

32 (17, 60)​

2.50 (1.23, 5.08)

10​

40.00​

30.00​

25.00​

1

50.00

Chonburi-1 (Bang Lamung)

12.899615,100.865698

1019 (2)

NA

–

–

30​

51.70*​

48.30

48.30

29

50.00

Chonburi-2 (Ban Chang)

12.695174,100.985838

1047 (2)

NA

–

–

33​

90.90**​

80.30

3.00

33

80.30

  1. LC = Lethal Concentration (% w/v). All mortality data was corrected using Abbott’s formula, (*), new alleles (c.190AA and c.190CG) were observed at position 190, (**), new alleles (c.190AA and c.190AG) were detected for position190 and both are homozygous resistant genotypes, (NA), larvae from this location were strongly resistant to permethrin, even at the highest concentration used (10% w/v) in the LPT assay: Chonburi-1 (Bang Lamung) = 0.9% mortality at 10% w/v permethrin, Chonburi-2 (Ban Chang) = 12% mortality at 10% w/v permethrin.
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