Insect galls found on Miyakejima and Hachijojima, the Izu Islands, Tokyo, Japan

Abstract

Cecidomyiid and other insect galls were surveyed from 2009 to 2011 on Miyakejima and Hachijojima, the Izu Islands, Tokyo, Japan. We found 18 and 21 sorts of cecidomyiid gall on Miyakejima and Hachijojima, respectively. Among them, leaf gall or necrosis on Machilus thunbergii (Lauraceae), leaf gall on Styrax japonica var. kotoensis (Styracaceae), and stem gall on Artemisia indica var. maximowiczii (Asteraceae) were newly discovered in this study. Stem gall induced on Castanopsis sieboldii (Fagaceae) was previously recorded only from Okinawa Island, but we revealed that it is distributed also on the Izu Islands. Furthermore, eight sorts of cecidomyiid gall were newly found from the Izu Islands, six sorts were from Miyakejima, and six sorts were from Hachijojima. As a supplementary result, two gall midge species newly found on Mikurajima Island were also reported in this study. Leaf gall induced by Trioza cinna- momi and Trioza nigra (Hemiptera: Psylloidea) was new to Miyakejima, and leaf gall induced by Liothrips kuwanai (Thysanoptera: Phlaeothripidae) and stem gall induced by Ornatalcides trifidus (Coleoptera: Curculionidae) were new to Hachijojima. Then petiole gall induced by Paratephritis fukaii (Diptera: Tephritidae) was recorded for the first time from Miyakejima and Hachijojima.