Author
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OKAMOTO, CHIE - KYUSHU UNIVERSITY,JAPAN |
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TSUDA, KIYOSHI - MINAMISATSUMA CITY.JAPAN |
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YAMAGUCHI, DAISUKE - KYUSHU UNIVERSITY,JAPAN |
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SATO, SHINSUKE - KYUSHU UNIVERSITY,JAPAN |
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Pemberton, Robert |
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YUKAWA, JUNICHI - KYUSHU UNIVERSITY,JAPAN |
Submitted to: Entomological Science (Japan)
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/12/2007 Publication Date: 11/5/2007 Citation: Okamoto, C., Tsuda, K., Yamaguchi, D., Sato, S., Pemberton, R.W., Yukawa, J. 2007. Life history traits and host specificity of Japanese Trachyaphthona species (Coleoptera:Chrysomelidae), candidates as biological control agents against skunk vine, Paederia foetida (Rubiaceae),in Southeastern U.S. & Hawaii.. Entomological Science (Japan), Vol. 11, Issue 2, pps. 143-152. Interpretive Summary: Skunk vine (Paederia foetida) is a coffee family (Rubiaceae) weed in Florida, the American South, and in Hawaii. This Asian native has invaded native vegetation where it dominates native plants. A biological control program is underway to develop biological control to attempt to lessen skunk vine’s presence and impact. Two flea beetles native to Japan were discovered which could have potential as biological control agents of the weed. Field surveys were made in Kyushu, Japan to determine the beetles’ distributions and activity periods. Laboratory studies in Japan were undertaken to define their life cycles and dietary ecology. Trachyahthona sordida was found to be distributed through Kyushu Island, while T. nigrita occurred only in the southern subtropical tip of the island. The adults of both beetles are present from late April to early July. The larvae of both flea beetles eat the fine roots of skunk vine. Both beetles have a single generation per year. T. sordida overwinters as mature larvae while T. nigrita overwinters as either a mature larvae or rarely as adult beetles. Preliminary host range testing suggests that both beetles may be specialists of the tribe Paederiae to which skunk vine belongs. Neither the continental US or Hawaii have any native or important economic plants in this tribe. If this level of specificity is confirmed by additional testing, the beetles will be safe enough to use as biological control agents of skunk vine in the United States. Technical Abstract: Skunk vine, Paederia foetida (Rubiaceae), is native to Asia and has been recognized as an invasive weedy vine of natural areas in Florida and Hawaii. It has overgrown on native vegetation and caused serious damage. The USDA Agricultural Research Service has been considering use of Trachyaphthona sordida and T. nigrita (Coleoptera: Chrysomelidae) as potential biological control agents against skunk vine. To gather fundamental information on their biology, we carried out field surveys and laboratory experiments in Kyushu, in southern Japan from 2003 to 2006. We found that T. sordida is commonly distributed in Kyushu and T. nigrita is restricted to southern parts of Kagoshima Prefecture on the southern part of Kyushu. They are fundamentally univoltine and adults appears in late April to early July. T. sordida overwinters as mature larvae and T. nigrita as mature larvae or rarely as adults. Larvae of both species fed on fine roots of P. foetida in the field, Serissa foetida (Rubiaceae) under rearing conditions, and appear to have tribe level host specificity in their host range. On the basis of these results, we suggested that both species are suitable as biological control agents. |