Distribution and daily activity of adult western flower thrips Frankliniella occidentalis (Pergande) under solar greenhouse condition

The distribution and daily activities of adult western flower thrips on eggplants under solar greenhouse condition were investigated in late March 2009. The thrips were surveyed using blue sticky traps. Results show that the number of adult western flower thrips caught in the solar greenhouse gradually decreases from north to south. The average catch in the north is 65.3 adults per group of blue sticky traps, that in the middle is 40.0 adults per group of blue sticky traps, and that in the south is 20.4 adults per group of blue sticky traps. Daily average catch differs significantly between the south and north. From west to east, the catch in the middle is less than those in the east and west. Vertically, adult western flower thrips are found on all the leaves of the eggplants. The adults caught by the blue sticky traps gradually increase from 7:00 am to 15:00 pm, then gradually decrease - indicating a single daily peak of activity. Generally, the traps facing south catch significantly more adult western flower thrips (330.6 adults per day) than the ones facing north (242.2 adults per day). Similarly, the traps facing east catch significantly more adults (343.8 adults per day) than the ones facing west (208.0 adults per day).