Geographic Distribution and Seasonal Composition of Reproductive Types of Onion Thrips, <i>Thrips tabaci</i> Lindeman in Kyoto Prefecture

Abstract

The relative abundance of the reproductive types of Thrips tabaci Lindeman was occasionally surveyed by collecting female adults from the foliage of commercially grown Welsh onions, onions, and cabbages at various locations in Kyoto Prefecture between 2016 and 2018. Arrhenotokous females were found at 39 of the 46 surveyed sites and coexisted with thelytokous females at 26 sites, of which the arrhenotokous composition was higher than that of thelytokous at 19 sites. The arrhenotokous type was dominant in Kyoto City and Kumiyama Town, and thelytokous females were found to be dominant in the areas north of Fukuchiyama City. In cabbage, only arrhenotokous females were observed. The seasonal composition of T. tabaci reproductive types was additionally surveyed in Welsh onion plants grown in greenhouses in Kameoka City, Kyoto Prefecture, between November 2016 and June 2019. Thelytokous females were dominant between November 2016 and March 2017 and arrhenotokous females dominated between April 2017 and March 2018, except for January 2018. After May 2018, the thelytokous type dominated again.