Identification Of Resistance Of Maize Varieties To Insect Pests And Characteristics Of Arthropod Community In Maize Field

In this study,the species and abundance of insect pests and their natural enemies on 75 maize varieties planted in Taian City,Shandong province were investigated,the resistance of 75 maize varieties to insect pests at different growth stages was identified;the population dynamics of pests and natural enemies were described;the dominant species and arthropod community characteristics of pests and natural enemies on different maize varieties were analyzed.The research provided a theoretical and practical basis for making full use of maize resistance against pests,giving play to the ecological benefits of natural enemies,and comprehensively controlling maize pests.The main results were as follows:1.The resistance levels of 75 maize varieties to main insect pests were identified according to the borer/aphid index.It was found that there were differences in the resistance levels of maize varieties among different maize varieties,and also at different growth stages of the same maize variety.There were no maize varieties with highest resistance to 3species of lepidopteran borer pests(Conogethes punctiferalis,Ostrinia furnacalis and Helicoverpa armigera).“Heyu 157”,“Longping 208” and “Yuqing 358” showed the medium resistance or above to the three Lepidopteran pests.There were more maize varieties with high resistance to Rhopalosiphum padi,Rhopalosiphum maidis and Aphis gossypii,but none of them showed highest resistance to the three species of aphids.2.The arthropod community in maize field was mainly composed of sap-sucking pests,leaf-feeding/borers pests,predatory natural enemies and parasitic natural enemies.There were 38 species of main pests and natural enemies in the arthropod community of all maize varieties,belonging to 1 phylum,2 classes,7 orders and 23 families.Among them,there were 11 species of pests and 27 species of natural enemies.In the whole community,among the pests,aphids and Lepidopteran larvae occurred in a large number;and among the natural enemies,the abundance of the spiders were dominant.The dominant species of aphids were Rhopalosiphum padi and Aphis gossypii,the dominant species of leaf-feeding/borers pests were Helicoverpa armigera,and the dominant species of natural enemies were Hylyphantesgraminicola,Coleosoma octomaculatum,Propylaea japonica,Harmonia axyridis and Aphelinus sp.3.The population dynamics of main pests and natural enemies in maize field were cleared,and the natural enemies showed obvious following phenomenon to pests.The population dynamics of Rhopalosiphum padi and Rhopalosiphum maidis were basically similar and peaked in mid-late September,while Aphis gossypii peaked in number in the early August.Helicoverpa armigera moved into maize field earlier and reached the peak in the late August,Ostrinia furnacalis peaker in mid-early September,Conogethes punctiferalis population increased since the late August.In September,Conogethes punctiferalis and Ostrinia furnacalis togather damaged the female ear of maize.The occurence peaks of natural enemies were similar,concentrated from the end of August to mid-late September.4.The characteristics of arthropod community on 75 maize varieties were analyzed.The results showed that there was a certain correlation between the resistance of Maize varieties to insect pests and community diversity.