Figure 2. Larvae conditioned with forward-paired shock+odor avoid EA at fifth instar.

Proportion of M. sexta larvae choosing ambient air rather than EA in the Y choice apparatus after receiving one of five treatments: no exposure to odor or electric shock (N = 46), shock only (N = 43), odor only (N = 29), the forward pairing of shock+odor at fifth instar (N = 41), or forward pairing of shock+odor at third instar (N = 32). Only larvae conditioned with shock+odor demonstrate a significant aversion to EA as larvae, and larvae trained at third instar recall the aversion at fifth instar, indicating retention of memory across molts. *** (p<0.001) indicates values that differ significantly from random choice (dashed horizontal line) by a two-tailed binomial calculation. Values are means±SD.