Virus Posted on November 8, 2022August 1, 2023 by Tex Norwood An infectious agent composed of DNA or RNA, too small to see with a compound micro-scope; multiplies only in living cells. Related Articles: (FMV) Virus-causing color break in PlumeriasGrafting and Budding OverviewPlumeria – Frangipani mosaic virusAphids – PestInsects – Pests