Tomato spotted wilt virus. Coloured transmission electron micrograph (TEM) of virus particles (virions) of the tomato spotted wilt virus (TSWV). This plant virus is a tospovirus, and has an RNA (ribonucleic acid) genome. It was first identified in 1919 in the tomato plant (Lycopersicon esculentum), a plant cultivated for its fruit. This virus also infects a wide range of other plants, including pineapple, date, sunflower, legume, soya, tobacco and potato plants. Symptoms are wilting, tissue death and a range of yellowing and leaf lesion patterns. The virus is transmitted by several species of thrip insects. Magnification: x67,000 when printed 10cm high.