A simple rearing system for Thrips setosus Moulton (Thysanoptera : Thripidae) using a leaf cage method for the transmission experiment of tomato spotted wilt tospovirus

We have developed a simple rearing system for Thrips setosus to facilitate the collection and maintenance of a large number of even-aged for use in tr ansmission experiments of tomato spotted wilt tospovirus. The system was es tablished using a leaf cage. The leaf cage consisted of an excised leaf of the plant, Vigna susquipedaris, sandwiched between two acrylic plastic plat es held by rubber bands. The upper plate had a 25 mm-diameter hole in the c enter and two air ventilation holes, while the lower plate was flat. In thi s cage, approximately 75% of the total egg number could be collected during the first 6 h of a 24 h oviposition period, indicating that the first 6 h of the oviposition period is practical to collect eggs efficiently using th is method. On day 6 after egg oviposition, 54.4% of the total number of hat ched larvae was observed in the former half of the photophase (within 8 h a fter onset of the photophase), suggesting that this period is efficient for collection of larvae with synchronized age. This method was useful not onl y to collect a lot of synchronously hatched first instar larvae, but also t o maintain them until adulthood without escape from the cage.