Popullation dynamics of an invasive grub moth Parasa lepida (Cramer) that damages ornamental trees : the seasonal and annual fluctuations of the cocoon density
Popullation dynamics of an invasive grub moth Parasa lepida (Cramer) that damages ornamental trees : the seasonal and annual fluctuations of the cocoon density
复制标题
损害观赏树木的入侵蛴螬（Cramer）的种群动态：茧密度的季节性和年度波动
DOI：
10.11257/jjeez.19.115
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
裕一 沢田
中科院分区：
文献类型：
--
作者：
裕一 沢田
We analyzed population dynamics of an invasive grub moth Parasa lepiaα(Cramer) (Lepidoptera : Limacodidae) in terms of the cocoon and adult density on various host plants consisting of 51 tree species of 404 individual trees at the campus of the University of Shiga Prefecture, Hikone, Shiga, western Japan during 5 years from 2003 to 2007. The cocoons occurred twice a year, the first generation in middle July -middle August and the second generation in middle September悶lateOctober. After hibernating as the pre回pupaewithin the cocoons, the adults of the second generation emerged during early June to early July in the following year. The mortality of cocoons was consistently higher in the second generation than in the first generation, resulting in the very low density of adults in the second generation. In the first generation, however, the survival rate of the cocoons decreased year by year from 91.0 % in 2003 to 45.1 % in 2007. The population growth rate from the second generation adults to the first generation cocoons (Rj) was higher when the adult density was higher, indicating the presence of the inversely density dependent processes in Rj. As the consequence the cocoon density fluctuated violently year by year in the first generation. In contrast , the population growth rate between the first generation adults and the second generation cocoons (Rz) functioned both density dependently and complementary with the adult density, resulting in the exclusively stable cocoon density in the second generation. We discussed ecological mechanisms in particular agents of larval mortality that were assumed to be responsible to the inversely density dependent processes and the density processes in Rj and Rz, respectively.