Figure 4. Change in detoxification enzyme induction between instars and also between whole leaf diets and plant extract diets towards various substrates. The bars represent the ratios of enzyme induction towards the respective substrates with the base line for no change at 1 on the y-axis: This is basically the row comparisons of Tables 2 and 3. Solid bars = 2nd to 3rd instar induction / 1st to 2nd instar induction, open bars = 3% v/w Extract induction / Whole leaf induction. Significant differences between induction ratios are denoted by *(P < 0.05) and ** (P < 0.01) t-test.