Brown spots on ornamental plant Spatiphyllum patinii caused by the flower thrips Frankliniella intonsa Trybom in glasshouses with automatic air conditioning system

摘要

We studied the cause of brown spots on spathe of ornamental plant Spathyphyllum patinii on artificially air conditioned glasshouses. The dominant thrips species observed on traps was Frankliniella intonsa Trybom, constituting more than 60 percent of trapped adults. Thrips were trapped most frequently in June during our survey. Adult thrips were less frequently trapped at two locations in glasshouses where was the farthest points from un-weaved cloth filter, through which air stream is introduced into the glasshouses. We found only adult thrips and never saw the immature stage (larva and pupa) on plants. There was significantly more number of adults on spadix than the other parts of the plants, and at middle stage of influorecense than the other stages. Oviposition on spathe by F. intonsa in laboratory condition generated brown spots, which was almost the same as observed symptom in glasshouses, indicating that scars of oviposition by F. intonsa caused brown spots, which was almost the same mechanism causing white swelling spots on tomato.