COMPARATIVE STUDIES BETWEEN THE APHID TRANSMISSION OF POTATO LEAF ROLL AND TURNIP LATENT VIRUSES

Abstract

Transmission of potato leaf roll and turnip latent viruses by Myzus persicae (Sulz.) were similar in that: (a) fasting aphids for 18 hours prior to inoculation feeding had no effect on the numbers that transmitted virus; (b) upper and lower surfaces of infected leaves of Physalis floridana Rydb. were equally good sources of virus; (c) top leaves of infected plants were better sources of virus than middle or bottom ones; (d) excised leaves were better sources of virus than whole plants for short acquisition feeding periods but not for longer ones; (e) when infective aphids fed on a small area of a leaf, they transmitted virus as often as those that fed on whole plants; (f) and more nymphs transmitted virus than adults.The transmission of the two viruses differed in that: (a) during comparable acquisition and inoculation feeding periods more aphids transmitted potato leaf roll than turnip latent virus; (b) fasting aphids for 18 hours prior to acquisition feeding had no effect on the numbers that transmitted potato leaf roll, but increased the numbers that transmitted turnip latent virus; (c) and three- or six-leaf P. floridana were equally good test plants for potato leaf roll, but more three-leaf ones became infected with turnip latent virus.