Study On Species Diversity Of Land Snails In Wuyi Mountain Nature Reserve And Field Experiment Of Pest Control By Pesticides

Based on the relationship between species diversity of land snails and different kinds of habitats,the impacts of environmental factors on the distribution of land snails from Wuyi Mountain Nature Reserve were discussed in this paper,by using principal component analysis(PCA),cluster analysis,species diversity indices and correlation analysis.Field trails were conducted finally,with a purpose to compare the effects of four pesticides against some kinds of land snails which threaten to farm produce.The work of species diversity analysis was undertaken in three districts,that is, Sangang,Pikeng and Guadun.Within each district,several sites were studied in different habitats,such as forest,shrub,bamboo,tea garden,farmland and habitats of the village.Large numbers of specimens were collected in total of 140 sites.Principal component analysis and cluster analysis were used to analyze land snail species in different habitats,The fauna of land snails in Wuyi Mountain Nature Reserve was quite abundant including Central China district,Southern China district,South -Western district,North-Eastern district,Northern China district and some other widespread species.Similar results were obtained when the 14 plots were grouped into two categories:forest,shrub,bamboo and tea garden;village and farmland.The result indicated that vegetation structure and human disturbance may be important factors that influence the species composition and distribution of land snail in Wuyi Mountain Nature Reserve.There were 6,903 land snails collected in this study.The diversity analysis showed that Wuyi Mountain Nature Reserve had high species diversity of land snails in different taxonomic levels,60 species,34 genera,17 families,4 orders and 2 subclasses.Richness index(d_MA),Shannon-Wiener index(H'),evenness index(Jsw) and simplicity index(P)were computed for the 14 habitats.The results indicated that the change of richness index(d_MA)was accordant with Shannon-Wiener index(H'), which both had the highest value in forest habitats and lowest value in village and farmland habitats.Evenness index(Jsw)had no obviously difference from all the habitats because of its special characteristic.Simplicity index(P)generally showed opposite value from Shannon-Wiener index(H').Separately,forest habitat,especially in Sangang,had the most abundant diversity considering species,genera and families compared with other habitats.On the contrary,the habitats of the village and farmland hold the lowest species diversity.The condition of land snail diversity in shrub, bamboo and tea garden was much better than that of the village and farmland but not as good as in the forest.The result of correlation analysis among common species was consistent with the analysis of the species distribution in different habitats.The results indicated that common species had an obvious tendency to live in different habitats,which could be found more frequently in forest,shrub and bamboo habitats.In addition,Bradybaena (Acusta)vavida redfieldi and Bradybaena(Bradybaena)similaris similaris could be easily found in farmland habitats.Field experiments of four pesticides for controlling land snails which could cause damage to the farm product were carried out.The results showed that the 15 d control effects of 6%Meta G,5%Metaldehyde G,6%Wokexing G and oil camellia reached 89.1%,92.5%,87.8%and 62.7%respectively.Though oil camellia exhibited lower effective control than other three pesticides,it could be worthy recommended as a botanical pesticide still.