Field Occurrence Dynamics And Natural Enemy Community Of Aphis Glycines In Changchun Area

In this paper,the field population dynamics and natural enemy community structure characteristics of Aphis glycines in Changchun area were studied by artificial investigation,yellow plate monitoring and net capture.At the same time,the temporal niche of Aphis glycines and its natural enemies and the regulation of Aphis glycines population in dominant days were preliminarily analyzed,and the dynamic regularity of Aphis glycines occurrence in field and the dominant natural enemy group of Aphis glycines were preliminarily defined.The main research results are as follows:(1)The results of field investigation and analysis showed that the Aphis glycines began to occur in the middle of June,and the number of Aphis glycines in the field appeared three times,the first peak occurred on July 20,the second peak occurred on July 30 and the third peak appeared on August 15.Aphid population was the largest in the field,and the dynamic of aphid population monitored by yellow plate was roughly the same as that of total aphid population.(2)The natural enemies of Aphis glycines in the field were investigated by yellow plate and net trapping methods.A total of 14 species of Aphis glycines and some predatory spiders were found in 5 orders,9 families.Among them,the dominant natural enemies were coccyridis septempunctata,Coccyridis septempunctata,Lygus floret and Laceoptera chinensis,and the occurrence time was earlier.The community characteristic structure diversity index of Aphis glycines insect community was higher,but the evenness index and dominance concentration index were lower,indicating that Aphis glycines insect community was stable in soybean field.(3)The field investigation showed that the niche width of ladybug was the largest among the dominant natural enemies of Aphis glycines,and the niche overlap index of spider and Assassin bug was the largest.The ecological overlap index between the Aphis glycines and its natural enemies was the largest.Coleoptera is the most dominant natural enemy of Aphis glycines in the whole period.The natural enemies of pulmonoptera and diptera occur more frequently in the middle and late period of Aphis glycines,which is one of the main controlling factors of Aphis glycines occurrence period.These results indicated that natural enemies of Aphis glycines played a certain role in regulating the occurrence of Aphis glycines.