Table 4 Comparison of rate of decay of repellents, percentage protection and log-transformed means of mosquito catches per hour in the semi-field system against Anopheles arabiensis and in the field against all mosquito species and Anopheles arabiensis

Semi-field evaluation against An. arabiensis

1

Y = −0.0765 + 1.0315

Lotion-based 15% DEET repellent

2.69

90.88 (84.25-98.03)

2

1.7

91.85 (84.85-99.43)

3

3.1

82.60 (70.39-96.93)

4

R² = 0.29138

4.63

65.97 (52.28-83.24)

1

Y = −0.119x = 0.9685

15% DEET in ethanol

4.65

75.55 (51.79-110.20)

2

3.63

70.76 (54.63-91.65)

3

R² = 0.08181

3.17

82.18 (61.19-110.36)

4

6.26

58.42 (40.45-84.36)

Field evaluation against all mosquito species

1

Y = −0.0077x + 0.8921

Lotion-based 15% DEET repellent

4.77

87.39 (76.49-99.83)

2

4.03

88.92 (79.15-99.88)

3

5.44

85.99 (76.30-96.90)

4

R² = 0.00174

8.03

83.98 (73.78-94.19)

1

Y = −0.0427x + 1.0009

15% DEET in ethanol

4.22

91.98 (84.14-100.55)

2

5.94

95.11 (91.02-99.37)

3

R² = 0.11871

10.89

87.87 (83.08-92.95)

4

13.5

79.03 (69.14-90.33)

Person

Field evaluation against An. arabiensis

1

Y = 0.0311x + 0.7904

Lotion-based 15% DEET repellent

1.22

92.58 (83.18-103.05)

2

1.25

100.00 (100.00-100.00)

3

1

92.60 (84.30-101.72)

0.06763

4

1.64

88.02 (76.15-101.75)

1

Y = 0.0208 + 0.6235

15% DEET in ethanol

0.72

95.20 (87.33-103.78)

2

0.94

94.93 (87.85-102.57)

3

R² = 0.045263

1.5

82.26 (61.18-110.61)

4

1.17

91.15 (83.82-101.31)