Studies On The Community Biodiversity And Dynamic Change Of Mites In Stored Grain

Stored grain mites are important pests which breed in food. In order to know the characteristics of stored grain mites community better, during the period of November2010to October2011, the diversity research on the stored grain mites was done under laboratory conditions. The main results are as follows:1、The stored grain mite community composition:the total mites captured were9295heads, belonging to5families and7generas. Tyrophagus putrescentiae was the dominant species, the ratio of the total captured was75.86%. The ratio of the total captured in spring was50.51%and30.97%in autumn respectively. Mites were mainly distributed in the middle level, in the upper level and the horizonntal zone of the granary. The dynamic curve of stored grain mites showed bimodal pattern, the May and the September were the two peaks, the average breeding density were42.897heads/g and17.372heads/g.2、The stored grain mite community diversity:The numerical rang of Shannon-Wiener diversity index was (0.75,1.5), Pielou evenness index was (0.25,0.65), Margalef richness index was (0.47,0.78), and Simpson dominance index was (0.43,0.85). The stored grain mites community diversity of different regions showed significant differences in different seasons and different survey found regions. By using the Jaccard index to analyze the stored grain mites community, the composi-tion of mite community showed very similar in several months.2、The dynamic of stored grain main mites:Tyrophagus putrescentiae and Cheyletus malaccensis were the main mites in this investigation.The seasonal fluctuation curves showed bimodal pattern. Tyrophagus putrescentiae and Cheyletus malaccensis were mainly distributed in the upper layer in different seasons.