Western Flower Thrips on Impatiens Under Greenhouse Conditions, Spring 1994

A total of 220 plants were potted individually in 10 cm pots on 20 May. These plants were separated into groups of 120 and 100 and placed into 2 separate double-poly greenhouses, thereby establishing 2 studies. In both studies, each treatment block contained 5 potted plants. The pots were arranged in a RCB design with 4 replications. Blocks were placed 50 cm apart. Test 1 consisted of 6 treatments and Test 2 consisted of 5 treatments. Treatments were applied at weekly intervals for 3 wk using a compressed-air sprayer operated at 30 to 35 psi, sprayed to runoff. A 75 × 120 cm masonite board was placed between plots to prevent overspray from one plot to another. Cell-U-Wet® (Creative Service,s Inc., Michigan City, IN) at 0.15 lb/gal was added to each tank mix in Test 2. Pre treatment and weekly post-treatment samples were obtained by excising 25 randomly selected flowers from each block and placing them immediately into 190-ml capacity plastic vials containing 80 ml of 70% ethanol. Each vial was shaken 10 times. The flowers were then removed from the vial, rinsed with 70% ethanol into the vial, and discarded. The adult and immature thrips captured in the alcohol were enumerated.