Ecology Research Of Acaroid Mites

Objective To study the composition,diversity and similarity of acaroid mites in the different habitats,and survey the seasonal dynamics and the spatial distribution pattern of Tyrophagus putrescentiae in the wheat warehouse,and explore the relationship between three ecological factors and seasonal dynamics of Tyrophagus putrescentiae.Methods Samples from warehouse,human habitat,work environment and external environment were collected.Acaroid mites were isolated by directicopy and Tullgren, identified and counted under microscope.The species richness,diversity,evenness, domination and community similarity were calculated by Margalef index,Shannon-Wiener index,Pielou index,Simpson index and Jaccard index,respectively.Samples from Sanhe warehouse were collected,examined and counted for T.putrescentiae and its natural enemy in every ten days,relative humidity and temperature were detected simultaneously.Dispersion pattern target,Taylor power method and Iwao m~*(?)regression analysis were used for analyzing the spatial distribution pattern of T.putrescentiae in the wheat warehouse.At the same time,gray theory analysis were served for analyzing the relationship between three ecological factors and seasonal dynamics of T.putrescentiae.Results A total of 3650 acaroid mites were detected in four different habitats, belonging to 7 families,20 genera and 32 species.Diversity analysis showed that the species number S ranged from 10 to 26,the species richness index R raged from 1.466 to 3.313,the species diversity index H' ranged from 1.905 to 2.773,the species evenness index J' ranged from 0.828 to 0.864 and the species domination index D ranged from 0.080 to 0.184.The species number S,the species richness index R and the species diversity index H' of acaroid mite community were the highest in warehouse,the species evenness index J' was the highest in external environment,while the highest value of species domination index D was observed in work environment.The acaroid mite community in work environment was most different from that in external environment.There were two peaking periods in June and September respectively.Dispersion pattern target values were as follow:I＞0,C_A＞0,m~*/(?)＞1.Taylor power regression equation was lg S~2=0.1245 + 1.4220 lg(?),and Iwao m~*(?)regression equation was m~*=3.5036+1.0478(?).The gray sequence of the ecological factors to larvae of T.putrescentiae was temperature＞natural enemy＞relative humidity,to nymphs and adults was relative humidity＞natural enemy＞temperature,and to the population was relative humidity＞temperature＞natural enemy.Conclusions The results suggested that habitat condition directly influenced the community structure and diversity of acaroid mites,and human disturbance was also an important affecting factor.The spatial distribution pattern of T.putrescentiae was aggregation distribution.The basic component was clumps and the aggregation was increased with population density.Relative humidity,temperature and natural enemy were important ecological factors effecting the population dynamic of T.putrescentiae.The prevalence curve of T.putrescentiae was bimodal pattern,and corresponding control methods could be carried out from June to September.