Field plots of cotton treated with methyl salicylate or untreated had significantly greater infestations of Pectinophora gossypiella (Saunders) than similar plots treated with phenylacetaldehyde. In laboratory tests, phenylacetaldehyde did not reduce hatch when applied to eggs of the pink bollworm oviposited on cotton leaves. However, laboratory female moths laid ca. 75% of their eggs on untreated plants when caged with treated and untreated cotton plants. Phenylacetaldehyde appears to be an oviposition inhibitor for the pink bollworm and may be useful for control.