Spatial relationship between Ricania speculum and its natural enemies based on the square variance analysis of cluster samples
Abstract： [Objectives] To analyze the
spatial relationships between
Ricania speculum and seven spider species
under different block size conditions.
[Methods] Block square variance analysis, grey
correlation, spatial aggregation intensity index, population aggregation mean
and the ρ index were used to analyze the spatial distribution of
R. speculum and the seven spider species in the Baihaozao tea garden, Hefei, Anhui
Province.
[Result] Correlations
between the peak of the mean square deviation of seven spider species and
R.
speculum indicated that the latter had the closest spatial relationship to
Erigonidium
graminicolum (0.781 1),
Clubiona japonicola (0.692 8)and
Neoscona
theisi (0.688 7). When the basic block sample number, K, was 1, 2, 4 or 8,
the diffusion coefficient C increased continuously with increasing number of
basic samples in the cluster, then decreased continuously in a uniform and
random manner. There was no significant difference in the spatial distribution
of
R. speculum and the spider species when the basic sample number
K in the cluster was 2, 4, 8 or 1. The
population
aggregation of Ricania speculum was in most cases > 2 and the result
of intraspecific factors alone. When the population aggregation mean, λ, was
positive, that of the spider species and R. speculum increased with
increasing basic sample number in the agglomeration. The minimum range of the
aggregation of individual clusters of R. speculum as determined by the
clustering method indicated a minimum of four basic samples in each cluster. [Conclusion] The results provide a scientific basis for
determining the optimum sample size for sampling Ricania speculum and
its natural enemies.