RETENTION AND TRANSMISSION CHARACTERISTICS OF ZUCCHINI YELLOW MOSAIC-VIRUS BY APHIS-GOSSYPII AND MYZUS-PERSICAE (HOMOPTERA, APHIDIDAE)

We found significant differences in the transmission efficiencies of zucchini yellow mosaic virus (ZYMV) by Aphis gossypii Glover at various preacquisition starving, and acquisition access times. Maximum transmission was obtained with a 1-h preacquisition starving time and a 5-min acquisition access time. For Myzus persicae (Sulzer), there were no differences in transmission efficiencies across all preacquisition starving, acquisition access, and inoculation access times. In experiments that used an aphid suspension technique for retention time assessment, 20% of A. gossypii transmitted 1 h after removal from ZYMV source plants and 12.5% transmitted after 3 h at 21-degrees-C. For M. persicae, 33% transmitted after 1 h and 5.6% transmitted after 3 h. No aphids of either species transmitted virus after 5 h at 21-degrees-C. At 8-degrees-C, 3.0% of A. gossypii transmitted after 3 and 5 h, and 1% transmitted after 10 and 20 h. At the same temperature, 11.1, 5.1, 2, and 1.9% of the M. persicae transmitted at times of 3, 5, 10, and 20 h, respectively, after removal from ZYMV source plants. Also at this low temperature, 1 of 100 M. persicae transmitted after 30 h. M. persicae transmitted ZYMV over a broader range of temperatures and humidities than did A. gossypii, which did not transmit virus in low-temperature, low-humidity conditions.