The cucurbitacin-containing feeding stimulant (Invite® EC) was attractive to second instar pickleworm larvae in the absence of a food source. Second instar pickleworm larvae also fed preferentially on cucumber fruits that were treated with a 1% (0.01×) solution of Invite EC compared with untreated fruit. However, 1% Invite did not stimulate feeding on artificial diet, squash leaves, or squash fruits. Concentrations of Invite as low as 0.001% were effective in increasing the efficacy of the velvetbean caterpillar, Anticarsia gemmatalis Hübner, multiply-embedded nucleopolyhedrovirus (AgMNPV) against second instar pickleworms. A 1% Invite solution also increased the efficacy of the celery looper, Anagrapha falcifera (Kirby), multiply-embedded NPV (AnfaMNPV) against second instar pickleworms.