Ten-year trend in insect fauna detected at the plant quarantine of Japan.

Annual and quantitative trends in import plant and insect pest fauna detect ed during plant quarantine are summarized for the periods of 1989-1998, bas ed on the statistics of the Plant Protection Station of Japan. Quantities o f imported fresh plants has increased during these 10 years, whereas that o f stored plants has scarcely changed and that of timber has decreased. Seve nteen orders of pests including insects and other invertebrates have been d etected during plant quarantine; seven orders (Coleoptera, Diptera, Hemipte ra, Lepidoptera, Thysanoptera, Acarina, and Stylommatophora) were significa ntly dominant. In 1989, more than 50% of the insect pests were from stored plants and timber, consisting of mostly Coleoptera and Lepidoptera. The det ection of insect pests from stored plants and timber has gradually decrease d. In 1998, the insect pests from fresh plants reached more than 70% in tot al, because the frequencies of insect pests from fresh plants has not chang ed for 10 years from 1989 to 1998. The above seven orders were universally detected from fresh plants. The significance of quarantine for fresh plants is discussed.