The Relationship Between The Chemical Materials In Bamboo And The Occurrence Of Eutomostethus Nigritus Xiao

Eutomostethus nigritus Xiao is the defoliator of the bamboo stands in Fujian Province. The results indicate that occurrence of the pest is periodic law . The population of next generation is drastically reduce after the occurrence, however, there is less study on the reasons and mechanisms. In this paper, the relationship between the occurrence of Eutomostethus nigritus Xiao and the environment was studied. At the same time,This article studied the changes of the damage caused by Eutomostethus nigritus Xiao on the content of the main secondary substances and nutritional substances of Phyllostachys heterocycla cv.pubescens. Analyzed the effect of larval growing which hand feed on the bamboo leaves at various damage degrees. Because of the Master of the occurrence law, we would improve the accuracy of the monitoring and forecasting.The results indicate that the occurrence of Eutomostethus nigritus Xiao is more serious in pure bamboo stand, but in mixed bamboo cedar forest, mixed bamboo hardwood forest in less. Because the stand structure and the bamboo quantity have effect on the occurrence of Eutomostethus nigritus Xiao, so it occurs seriously in high bamboo quantity, reasonable stand structure and many underyearlings bamboo of stand structure, that is occurrence of Eutomostethus nigritus Xiao of mixed bambooshoot bamboo forest, timber forest have more serious than bambooshoot forest. These is more seriously occurs in bamboo stand at below 66metres, sunny-slopes more serious than shady-slopes. The ones in midslope and downslope lighter.In this paper, the content of tannin in leaves increase after the damage caused by Eutomostethus nigritus Xiao. The content of tannin is 0.386 mg·g-1 in unharmed leaves,0.553 mg·g-1 in severe harmed leaves; The content of phenols in leaves decrease after the damage caused by Eutomostethus nigritus Xiao. The content of phenols is 3.763 mg·g-1 in unharmed leaves, 3.126 mg·g-1 in moderate harmed leaves, and 2.653 mg·g-1 in severe harmed leaves; The content of flavonoids in leaves increase after the damage caused by Eutomostethus nigritus Xiao. The content of flavonoids is 2.631 mg·g-1 in unharmed leaves, 3.658mg·g-1 in moderate harmed leaves.The content of soluble sugar in leaves decrease after the damage caused by Eutomostethus nigritus Xiao. The content of soluble sugar is 111.36mg·g-1 in unharmed leaves, 97.64 mg·g-1 in moderate harmed leaves, and 86.71 mg·g-1 in severe harmed leaves. The content of total sugar is 250.22mg·g-1 in unharmed leaves, 236.42 mg·g-1 in moderate harmed leaves, and 215.65mg·g-1 in severe harmed leaves. The content of protein is 148.66 mg·g-1 in unharmed leaves, 135.41mg·g-1 in moderate harmed leaves, and 121.98mg·g-1 in severe harmed leaves.The growing of first generation larvae is affected, when they hand feed on the bamboo leaves at various damage degrees. So slower growing, higher mortality, lower pupal rate, lower female ratio, down reproduction and less population were found as fed on moderate damaged and severe leaves of Eutomostethus nigritus Xiao. But growing, mortality, pupal rate, emale ratio and reproduction after fed on healthy leaves like after fed on lighter leaves.