西宁地区草坪地下害虫种类构成及动态分析

Species composition and dynamics of underground pests of lawn in Xining

2013年对西宁地区多年生黑麦草＋草地早熟禾＋高羊茅混播草坪地下害虫种类构成及动态进行调查分析。结果表明：危害西宁地区草坪0~20 cm土层的地下害虫主要为小云斑鳃金龟的幼虫蛴螬、沟金针虫和地老虎,0~10 cm土层蛴螬、沟金针虫和地老虎虫口密度分别为10.0~21.2头/m2,1.6~3.4头/m2,0~7.6头/m2,10~20 cm土层蛴螬、沟金针虫和地老虎虫口密度分别为0.6~1.8头/m2,2.6~5.6头/m2,0~2.0头/m2,地下害虫主要分布于0~10 cm土层。多巴和生物园区的3种地下害虫在5-8月呈先增加后降低趋势,而三角花园的蛴螬虫口密度在5-6月呈显著下降趋势（P〈0.05）;多巴、生物园区和三角花园的蛴螬虫口密度均显著高于沟金针虫和地老虎（P〈0.05）,危害最为严重。

The composition and dynamics of soil pest in Lolium perenne ＋ Poa pratensis ＋ Festuca ela- ta mixed lawn was investigated in Xining region in 2013. The results showed that the species of soil pests of lawn in Xining consisted of larva of Polyphylla gracilicornis, Pleonomus canaliculatus and Euxoa segetum, their population densities was 10.0 - 21.2 head/m2, 1.6 - 3.4 head/m2, 0 7.6 head/m2 in 0 - 10 cm, and was 0.6 - 1.8 head/m2, 2.6 ~ 5.6 head/m2, 0 - 2.0 head/m2 in 10 - 20cm, respectively. The underground pests are mainly distributed in 0 - 10 cm soil layer. The population densities of soil pests of Dopa and Biological park showed a increasing to reducing trend from May to August, whereas the population density of a larva of Polyphylla gracilicornis in Triangu- lar Garden significantly decreased （ P 〈 0.05 ） from May to June. The population density of a larva of PolyphyUa gracilicornis in this three sites was signifi latus and Euxoa segetum （ P 〈 0.05 ）, and Polyphylla region. cantly higher than that of Pleonomus canalicu- gracilicornis was the most serious pest in this