Influence of some environmental conditions on stability and activity of Bacillus thuringiensis formulations against the cotton leaf worm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

Egyptian Journal of Biological Pest Control

Table 7 Effect of exposed to UV light of the Bacillus thuringiensis formulations

Time/hour	Bacillus thuringiensis
	Dipel 2×		Protecto
	IU/mg	Loss %	IU/mg	Loss %
0	28,800	0	27,733	0
1	26,667	7.41	24,533	11.54
2	22,400	22.22	20,267	26.92
4	17,066	40.74	16,000	42.31
8	12,800	55.56	9600	65.38
Regression equation y =	− 0.0870x + 10.25		− 0.1098x + 10.22
Degradation rate (K)	0.08697		0.10985
t_½ h	7.97		6.31
Determination coefficient (R²)	0.96		0.99