Anti‐predatory autecology in the geometrid larvae of Larentia clavaria pallidata

Abstract It was suggested by Heinrich that cryptic, palatable caterpillars would adopt foliar foraging techniques which would reduce the chance of their being detected. I wished to test this hypothesis further and to determine the post‐discovery tactics. I found that caterpillars of Larentia clavaria pallidat , contrary to expectations, usually rested on upper surfaces of young Althaea setosa leaves but moved to the undersides when exposed to higher light intensities. This species may be effectively concealed by older canopy leaves. These larvae usually responded to predator‐like stimuli by assuming a deimatic ‘s’ form but rarely dropped. Dropping may be infrequent partly because younger caterpillars could not easily relocate the foot plant. I discuss, briefly the implications of host‐plant selection.