Abstract.1Foraging patterns of the squash beetle,Epilachna borealisFabricius (Coleoptera: Coccinellidae), in field cages are not consistent with the hypothesis that this beetle avoids leaves in which its feeding damage has caused the induction of cucurbitacins.2E.borealisfeeding does not induce accumulation of cucurbitacins inside or outside of feeding trenches.3Cucurbitacins do not reduce the survival or growth rate ofE. borealislarvae.4High concentrations of cucurbitacins fail to deterE.borealisfeeding; rather, cucurbitacins are feeding stimulants for squash beetles.5Trenching behaviour inE.borealisis facultative and correlates with leaf turgor and the degree to which sticky phloem sap oozes from damaged leaves.6Mucilaginous phloem sap in many curcurbit species inhibits feeding byE.borealiswhen it is applied to beetle mouthparts.