Fig. 3. The contractions of the foregut were monitored using a movement transducer attached to anterior esophageal constrictor (aEC) muscles. (A) Output of the movement transducer recorded during the intermolt 4th and 5th instars, as well as during the molt between the two larval stages. Molting stages are given in hours after head capsule slippage (HCS). There were no significant differences in the mean period of contraction between any larval stages. Scale bars, 30 µm and 2 s. (B) A movement transducer was used to determine the mean maximum amplitude of movement (± S.E.M.) for each stage. The asterisk represents significant difference from early-molt values (P<0.05, N=9–37).