Growers are also aware that INSV diagnosis is difficult due to widely variable symptoms on a variety of plants. Over the past several years, the UMass Plant Pathology Laboratory has diagnosed many cases of INSV in spring crops, cyclamen and gloxinia. Some growers have had a small number of plants infected with INSV on the same crops each year, while others have lost significant numbers of plants. Growers concentrating all of their plants in a single house during winter months run a greater risk of mixing INSV-free seed crops with either leftover fall crops, or new cutting crops that may carry the virus. Once symptoms suggest that INSV may be present, growers can confirm their suspicions using their own test kits or by sending samples to a diagnostic lab.
Some growers find the test kits to be a convenient and valuable tool.
Most growers, however, still send samples to a laboratory for confirmation. Costs of the INSV tests have been partially supported by the UMass Agroecology IPM Program. A grower s best defense against INSV is to detect it before it destroys a crop. Several years ago, research was conducted using indicator plants to detect the presence of INSV infected thrips in a greenhouse. A few growers tried using indicator plants when the information first came out, but for the most part, growers haven t adopted this practice.