It is now known that there are two different but closely related viruses that cause greenhouse symptoms. This virus causes problems on plants such as garden impatiens, New Guinea impatiens, cyclamen, cineraria and gloxinia. Both viruses have a very wide host range. Both are vectored by Western flower thrips and other thrips species. TSWV-L and INSV can be difficult to diagnose because symptoms vary from plant to plant and according to conditions in the greenhouse.
Some plants develop small concentric rings on the foliage or fruit.
On other plants, leaf veins or stems become discolored. Flowers may show abnormal coloration. Plants may show symptoms of stunting. Some plants may be infected yet show no visible symptoms. Because visual diagnosis can be difficult, suspect plants should be tested for the virus.