Hemlock Woolly Adelgid Biocontrol Research in Japan
The purpose of this project is to research the life history, natural enemies, climatic adaptation, and genetic structure of Adelges tsugae, the hemlock woolly adelgid (HWA), in Japan. The adelgid in the Kansai Region of Japan is genetically identical to that of the HWA in the eastern U.S. This research will provide a better understanding of the nature and application of biological control of HWA.
- Determine the seasonal occurrence of HWA and its natural enemies in Kansai Region
- Provide description and life history information on new species of Laricobius
- Survey other areas of Japan for HWA and natural enemies
- Collect and ship Laricobius and other natural enemies to the U.S.
- Determine the geographical, environmental, and host ranges of Sasajiscymnus tsugae in Japan
- Provide information on climate and distribution of hemlock, HWA, and its natural enemies
- Collect HWA from various locations for determination of genetic variability geographically and on different host species
- Comparison of the climate and dynamics of the source population of HWA with its dynamics in eastern U.S.
- Increased knowledge of the life history of Adelges tsugae and its natural enemies in Japan
- Description and other information of the newly discovered species, Laricobius osakensis, for its use as a new biological control agent for HWA
Survey for HWA and natural enemies was made in 17 prefectures in four of the islands that make up Japan. The adelgid was present in almost all the areas where hemlock was present. Adelges tsugae was collected for molecular analysis from Yakushima Island in southern Japan to Amori Perfecture in northern Honshu Island. Additional galls of A. tsugae were found on tigertail spruce, Picea torano. Climatic data were collected and the annual mean temperature examined for the distribution of hemlock in Japan and HWA natural enemies.
The phenology of HWA in the Kansai Region on Honshu Island, Japan was found to be similar to that of HWA in the eastern U.S., which is not surprising because the adelgid in this region is identical to that of the adelgid in the eastern United States. The distribution of the lady beetle Sasjiscymnus tsugae was much more restricted then previously reported. It was not found in mountainous areas or where Tsuga diversifolia naturally occurs. It was abundant only in cold-hardiness zone 7 or warmer in the Kansai Region on Tsuga sieboldii with a few specimens collected in coastal areas on pine, where hemlock does not occur.
A new species of Laricobius was collected from several areas ranging from 500-2500 meters elevation and on both species of Japanese hemlocks. It was exported to the United States for mass-rearing and study in quarantine at Virginia Tech University.
Generalist predators such as cantharid beetles also seem to have an important role in HWA regulation in Japan. Fifteen species of Coccinellidae and four species of Anthocoridae were collected from adelgids.
Montgomery, M. E.; Shiyake, S.; Havill, N. P. 2011. A new species of Laricobius (Coleoptera: Derodontidae) from Japan with phylogeny and a key for native and introduced congeners in North America. Annals of the Entomological Society of America. 104: 389-401.
Lamb, A.; Montgomery, M. E.; Shiyake, S.; Viera, L. C.; Salom, S. 2011. Laricobius osakensis, a hemlock woolly adelgid predator from Japan. In: Onken, B.; Reardon, R. eds. Implementation and status of biological control of the hemlock woolly adelgid. FHTET-2011-04. Morgantown, WV: U.S. Department of Agriculture, Forest Service Forest Health Technology Enterprise Team: 77-96. Chapter 7.
Shiyake, S,; Miyatake, Y,; Montgomery, M.E.; Lamb, A. 2008. Hemlock woolly adelgid phenology and predacious beetle community on Japanese hemlocks. In: In: Onken, B.; Reardon, R., eds., Fourth symposium on hemlock woolly adelgid in the eastern United States. Hartford, CT; U.S. Department of Agriculture, Forest Service, Forest Health Enterprise Team: 261-266.
Shiyake, S. 2007. A record of Sasajiscymnus tsugae at Koyasan, Wakayama Pref. Kinokuni (Wakayama Entomological Association) 71: 8
- Nathan Havill, Research Entomologist, U.S. Forest Service, Northern Research Station
- Michael Montgomery, Research Entomologist, U.S. Forest Service, Northern Research Station
- Shigehiko Shiyake, Osaka Museum of Natural History, Osaka, Japan
- Ashley Lamb, Virginia Tech University
Last Modified: 05/08/2015