White Grubs Occurrence Characteristic And The Potential Mecnanism In Xiaoxian County, Anhui Province

Grubs are an important and general underground pests in Xiaoxian County,Anhui Province.The key and important issue to the grubs IMP relied on the precise prediction of its occurrence as well as its source track.Our research aimed to explore the relationship between grubs dynamic and precipitation,the source of grubs feeding on summer soybean in Xiaoxian county based on the field survey data conducted in 2011,2012 and 2014.We used ANOVA,NMDS and regression analysis to test our assumption.Our major results were as follows:1.We found 9 grub species belonging to 3 families in 2011,11 species belonging to 3 families in 2012 and 9 species belonging to 3 families in 2014.The dominant species of crop field in 2011 was Holotrichia parallela Motschulsky,Serica orientalis Motschulsky in 2012 and Maladera ovatula(Fairmaire)and Maladera ovatula(Fairmaire).However,the dominant species in poplar grove was constantly Maladera ovatula(Fairmaire).In terms of density,2014 was the lowest year than other two years.2.The precipitation was considered be a major factor on crop field grub occurrence.Our result showed that grub occurrence in August was strong correlated with the monthly average daily precipitation from April to July,and average daily precipitation in April,June and July,separately.The average daily precipitation in May and July other than June were positively related with grub occurrence in August.Of which,the average daily precipitation in July had the strongest relation with grub occurrence in August.3.Wheat seed dressing demonstrated a good control effect on grub,particularly in a great reduction of overwintering grubs.Accordingly,the grubs in wheat field seemed not the grub source for the summer crops such as soybean.Instead,grubs living in the wood land along the crop field were the potential source for summer crops.We found a strong linear increase of grub density with the distance decrease to the wood land(R2=0.21-0.87,p<0.01).In summary,we found the obvious species composition difference among 2011,2012 and 2014,and the grub occurrence was strong correlated with monthly average daily precipitation intra a single or intra months from April to July.Wheat seed dressing was a effectively way in reduction of overwintering grubs in wheat field.Our results provide more evidence on grubs in wood land are the potential grub source that feeding on summer crops such as soybean.