Collier's New Encyclopedia (1921)/Hop worm

HOP WORM, a form of caterpillar. In June, July, and August, the leaves of the hop-vine are often devoured by these active, slender, grass-green caterpillars, with but four pairs of prop-legs. They may be shaken off and the vines saved by daily spraying with whale-oil soapsuds or kerosene emulsion.