|Cho0, Ho Yul|
|Lee, Dong Woon|
Submitted to: Proceedings of the Emerald Ash Borer and Asian Longhorned Beetle Research and Development Review 2006
Publication Type: Abstract Only
Publication Acceptance Date: 12/18/2006
Publication Date: 3/20/2007
Citation: Bray, A., Bauer, L., Fuester, R.W., Cho0, H., Lee, D., Kamata, N., Smith, J.J. 2007. Expanded explorations for emerald ash borer in asia and implications for genetic analysis. Proceedings of the Emerald Ash Borer and Asian Longhorned Beetle Research and Development Review 2006. USDA Forest Service. FHTET-2007-04. p. 6-7. Interpretive Summary:
Technical Abstract: Emerald ash borer (EAB) is considered native to northeast China, Korea, Japan, Taiwan, Mongolia, and eastern Russia. We are using genetic analyses to determine the origin of North America’s EAB infestations; however, acquiring samples from countries other than China has been difficult. To increase the diversity of EAB populations sampled in Asia, an expanded survey was made in areas of South Korea, Japan, and China from June-August 2006. Live ash trees (Fraxinus spp.) were examined for symptoms of EAB infestation. If symptoms were observed, bark was peeled at breast height to inspect the trees for larvae. Leaves and branches were sampled using an aerial net to sweep for adult beetles. In South Korea, six new field sites were evaluated for EAB from late June to mid-July. Fraxinus rhynchophylla was the ash species at our sites. Larvae were collected at five sites (Mt. Juri, Mt. Muju, Mt. Sangju, Mt. Wolak, and Jurisan National Park), while two adults were collected at the Suwon site. A single adult was also collected at Mt. Sangju. Most larvae collected in South Korea were early instars. Six field sites were evaluated in Jilin and Tianjin provinces of China from mid-July to mid-August. Live larvae were collected at three of the six field sites (Dagong in Tianjin province and JingYueTan Park and Jiang Nan Forest in Jilin province). All live larvae were placed on artificial media, shipped to the Forest Service containment room at Michigan State University to rear any parasitoids, and healthy raised EAB will be used for genetic evaluation. Finally, eight field sites were evaluated in Japan throughout the remainder of August 2006. No EAB were detected at seven of the eight sites (Otsuki, Morioka, Iwaki-san, Aomori, Odate, and the University of Tokyo Tanashi and Chiba stations), but two larvae were collected from F. lanuginosa at Mt. Zao near Shirioshi City. These larvae, however, could not be distinguished as EAB or A. koyoi, another Agrilus species attacking F. lanuginosa in this area of Japan. Therefore, they were placed on artificial diet to rear to the adult stage. Healthy EAB specimens will be used for genetic analysis to determine 1) the geographic origin of North American EAB populations; 2) the number of EAB introductions; 3) invasion history; 4) possible changes in EAB biology; and 5) sites in Asia for discovery of potential EAB biological control agents. Specimens will be evaluated by a variety of genetic techniques, including mitochondrial cytochrome oxidase I (COI) gene sequencing, amplified fragment length polymorphisms (AFLP), nuclear gene sequencing, and microsatellite analysis. Preliminary data from samples collected before the summer of 2006 observed COI haplotype diversity in South Korea, while the common haplotypes shared by all Chinese and North American EAB individuals exist in each of the Korean populations sampled, and a single Japanese specimen had a 3.7% divergence from the common haplotype (Bray et al. 2006). We expect that genetic analyses of our expanded data set will improve resolution of the EAB populations, allow us to determine which populations are most closely related to each other, and see if the North American infestations resulted from single or multiple introductions. Knowledge of EAB genetics will be useful in understanding the invasion dynamics of the beetle and identifying geographic localities of potential biocontrol agents.