Table 2 Population densities of Tetranychus urticae (N) on hydroponic cucumber and effectiveness of biopesticides

Matrine

28.6^a

11.3^a

− 60.4

76

23.0^a

− 19.7

62

8.0^a

− 72.0

69

2.3^a

− 91.8

88

Spintoram

26.3^a

25.3^a

− 3.7

41

27.6^ab

5.0

53

6.3^a

− 75.9

78

2.3^a

− 91.1

86

Azadirachtin

30.0^a

25.0^a

− 16.6

47

13.6^a

− 54.4

79

22.0^b

− 26.6

31

14.6^b

− 51.1

31

Custard apple

33.3^a

33.3^a

− 1.0

33

6.0^a

− 82.0

91

3.3^a

− 90.0

89

2.6^a

− 92.0

85

Control

40.3^a

67.6^b

67.7

88.3^b

119

45.6^c

13.2

55.0^c

36.3

Significance level

F = 0.61; df = 4; P ≥ 0.05

F = 19.6; df = 4; P ≤ 0.01

F = 5.52; df = 4; P ≤ 0.01

F = 95.9; df = 4; P ≤ 0.01

F = 12.5; df = 4; P ≤ 0.01