Cucurbita pepoL. (zucchini) plants infected with zucchini yellow mosaic virus (ZYMV) for 4 wk were rejected as colonization hosts byAphis gossypiiClover (melon aphid) alatae in the field at a greater rate than un infected zucchini and plants infected for 2 wk. Using an electronic feeding monitor to examine the feeding behavior ofA. gossypiion plants treated similarly, the study found fewer probing events, more phloem contacts, and more nymphs produced on uninfected zucchini and plants infected for 2 wk, than on plants infected for 4 wk. When phloem contact was made on plants infected for 4 wk, alatae spent more time in salivary sheath formation and less time phloem feeding than alatae on uninfected plants, and plants infected for 2 wk. These colonization and feeding responses could enhance ZYMV acquisition from zucchini.