关键词: 长足大竹象, 幼虫种群动态, 预测模型, 平均气温, 最低气温

Abstract:

Ground life history of Cyrtatrachelus buqueti, a main bamboo pest, is markedly impacted by temperature. From 2004 to 2008, the eggs and larvae in all bamboo shoots in three plots of a bamboo forest were regularly investigated in Muchuan, Sichuan Province. The principal component analysis,as well as correlation and path analysis and decision coefficient, was conducted to study effects of main climate factors on larvae population dynamics. The results showed that the larvae population fluctuation exhibited a single peak, occurred in August, and the larvae population density gradually tended to zero level after early October. The results suggested that the most important limiting-factor and the most important decision factor of larvae population fluctuation were respectively the mean temperature and the minimum temperature. Two forecasting models for the larvae population fluctuation were established, i.e. , C. buqueti larvae density (Y) and mean temperature(X) follow the equation of Y=-0.535+0.031X, and C. buqueti larvae density(Y) and minimum temperature (X) follow the equation of Y=-1.594+0.600lnX. Based on these results, forecast tables for C. buqueti larvae density were provided, and two temperature guide lines, mean temperature of ten days 21.5 ℃ or minimum temperature of ten days 17.7 ℃ , for controlling larvae density of C. buqueti, were suggested too.

Key words: Cyrtatrachelus buqueti, larvae population dynamics, forecasting model, mean temperature, minimum temperature