Spatial distribution pattern and space dependence of Contarinia sp.and Erigonidium graminicola in jujube orchard
枣园中枣瘿蚊和草间小黑蛛的空间分布格局及空间依赖性

With the principles and methodologies of geostatistics,this paper studied the spatial structure and space dependence of Contarinia sp.and its natural enemy Erigonidium graminicola in a jujube orchard at different date.The results indicated that the semivariogram of Contarinia sp.on 8 June,27 August and 19 October could be described by spherical model,showing an aggregated spatial distribution with the ranges of spatial dependence being 26.3,7.8 and 22.0 m,and the degrees of spatial dependence being 88.05%,85.77% and 87.58%,respectively.The semivariogram of Erigonidium graminicola could be also described by spherical model,showing an aggregated distribution with the ranges of spatial dependence being 28.3,22.5 and 22.2 m,and the degrees of spatial dependence being 90.09%,87.96% and 85.72%,respectively.It is suggested that Erigonidium graminicola is the dominant natural enemy against Contarinia sp.population in the examined jujube orchard.