FATE OF VIRUSES IN BEAN-LEAVES AFTER DEPOSITION BY EPILACHNA-VARIVESTIS, A BEETLE VECTOR OF PLANT-VIRUSES

Fluorescent antibody labeling was used to detect plant viruses within bean leaves after virus was deposited by Mexican bean beetles previous ly fed purified virus. Two to three days post feeding, southern bean m osaic virus (SBMV) and bean pod mottle virus, two beetle-transmissible viruses, were detected in veins leading from the feeding wound, and p rimary infection sites occurred close to feeding wound sites in mesoph yll cells associated with these veins. In addition, SBMV antigen and i nfection sites were detected at some distance from the feeding wound. The location of infection sites for both viruses was confirmed by viru liferous beetle feeding on local lesion hosts. Two non-beetle-transmis sible viruses, tobacco ringspot virus and tobacco mosaic virus, were d etected only on the edges of feeding wounds at 2-3 days after feeding. At 4-12 h after feeding, all four viruses were found in veins leading from the feeding site, although the non-beetle-transmissible viruses were found in fewer veins and were not detected far from the feeding w ound. These results suggest that non-beetle-transmissible viruses intr oduced by beetle feeding are translocated in veins but to a lesser ext ent than beetle-transmissible viruses.