Haplothrips(Thysanoptera: Phlaeothripidae)Fauna of Okinawa Prefecture and New Notes on the Predation and Development of Haplothrips chinensis and Haplothrips gowdeyi

The phlaeothripid fauna of Okinawa Prefecture, Japan was investigated in and around cultivated fields during 2009-2018. A total of 295 individuals representing four species belonging to the genus Haplothrips were collected from weeds comprising a wide range of plant taxa. The collected specimens included Haplothrips chinensis( 87.5%) as well as H. aculeatus, H. ganglbaueri, and H. gowdeyi. Haplothrips brevitubus, which is commercially available in Japan, was not found. Almost all the phlaeothripid individuals collected from the crop fields were identified as H. chinensis. The most common phlaeothripid thrips in our surveys, H. chinensis, was often collected with thripid thrips. We first evaluated the predatory potential of H. chinensis and H. gowdeyi for Thrips palmi in the laboratory. Our results demonstrated that H. chinensis could consume as many larvae of T. palmi as was observed for H. brevitubus. The mean developmental periods of the three species were also examined at 25, 20, and 15 degrees C under long-day( 16L:8D)and short-day( 10L:14D)conditions. The results of the laboratory tests and field surveys indicated that H. chinensis may have a high potential as one of the key indigenous natural enemies of thripid thrips in subtropical areas.