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

Abstract

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 transmission experiments of tomato spotted wilt tospovirus. The system was established using a leaf cage. The leaf cage consisted of an excised leaf of the plant Vigna sus-quipedaris, sandwiched between two acrylic plastic plates held by rubber bands. The upper plate had a 25 mm-diameter hole in the center and two air ventilation holes, while the lower plate was fiat. In this cage, approximately 75% of the total egg number could be collected during the first 6 h of a 24 h oviposition pe-riod, indicating that the first 6 h of the oviposition period is practical to collect eggs efficiently using this method. On day 6 after egg oviposition, 54.4% of the total number of hatched larvae was observed in the former half of the photophase (within 8 h after onset of the photophase), suggesting that this period is efficient for collection of larvae with synchronized age. This method was useful not only to collect a lot of synchro-nously hatched first instar larvae, but also to maintain them until adulthood without escape from the cage.