黄脊竹蝗产卵偏好生境因子分析

Habitat factor analysis of oviposition preference in Ceracris kiangsu

黄脊竹蝗(Ceracris kiangsu)是我国南方竹区危害较大的竹子害虫之一,分析影响黄脊竹蝗产卵选择和产卵量的相关生境因子,为黄脊竹蝗的综合防治提供理论基础。在黄脊竹蝗暴发区选取产卵地与非产卵地,通过测定土壤因子(土壤含水率、营养元素)、林分因子(新竹数量、老竹数量、竹林盖度、植被盖度)以及立地因子(天窗面积、坡向、海拔等),通过对比分析研判影响竹蝗产卵选择的生境因子,同时统计不同产卵地竹蝗卵块数,明确影响黄脊竹蝗产卵量的关键因子。黄脊竹蝗偏好将卵产于向阳的南坡中下部,竹林天窗存在有利于黄脊竹蝗产卵。产卵地与非产卵地在海拔上无显著性差异(P>0.05);产卵地与非产卵地在新老竹比例、竹林盖度、全磷、钾、土壤含水率上存在显著性差异(P<0.05);Pearson相关性分析显示,竹子数量及土壤含水率与卵块数存在高度相关,海拔与卵块数存在负相关。新老竹比例、土壤含水率是影响黄脊竹蝗选择产卵地偏好的主要因子,竹子数量、土壤含水量是影响产卵量的关键因子。

Ceracris kiangsu is one of the major defoliators in the bamboo distribution area in southern China.Understanding the relevant habitat factors affecting oviposition preference and fecundity of C.kiangsu can provide a theoretical basis for the integrated control of C.kiangsu.In bamboo forests with C.kiangsu outbreak,oviposition sites of the females and non-oviposition sites were selected,and ecological factors as soil factors(soil water content and soil nutrients),bamboo stand factors(number of one-year-old and two-year-old bamboo,bamboo canopy coverage,and vegetation coverage)and habitat factors(including skylight area,aspect,and elevation)were investigated.The critical factors affecting oviposition preference and fecundity of C.kiangsu adults were determined by comprehensive comparative analysis.The results showed that C.kiangsu preferred to lay eggs in the lower-middle part of the southern side slope facing the sun,and that the skylights were conducive to C.kiangsu oviposition.The oviposition site was independent of altitude(P>0.05).We found that significant differences in the ratio of one-year-old bamboo individuals to two-year-old bamboo individuals,bamboo canopy coverage,total phosphorus content,potassium content,and soil water content between oviposition sites and non-oviposition sites(P<0.05).There were positive correlations between the number of bamboo,soil water content and the number of egg masses,and a negative correlation between altitude and the number of egg masses.The ratio of one-year-old and two-year-old bamboo individuals and soil water content were the predominant factors affecting the choice of oviposition sites.The number of bamboo individuals and soil water content were the key factors affecting the number of eggs laid by C.kiangsu in the bamboo forests.