Fig. 2.

Percentage of M. sexta caterpillars in the second instar in the control and predation risk treatment at 3, 6, and 9 d after the start of the experiment. All caterpillars are either second or third instar; thus, the differences from 100% are third instars. Numbers in each instar on each day are compared across treatments using a G-test (day 3: G = 8.15, P = 0.0046; day 6: G = 0.58, P = 0.45; day 9: G = 5.2, P = 0.024). Asterisks indicate statistical significance. Sample sizes were as follows: day 3: control = 37, predation risk = 41; day 6: control = 29, predation risk = 25; day 9: control = 25, predation risk = 20.