The Resistance Of Maize Varieties To Insect Pests And The Population Dynamics Of The Main Species Of Lepidopterous Larvae Damaging Maize Ear

The insect pest quantities on 48 maize cultivars in field were investigated to identify the insect resistance and analysize the population dynamics of lepidopterous larvae.1.The resistance of different maize varieties to insect pestsThrough investigating the number of the larvae of the main maize pests,the pest indices were used to valuated the resistance of 48 maize cultivars.All of the maize varieties which were used to test,there were 13 maize varieties showing stabilized resistance to Rhopalosiphum maidis Fitch;there were 6 maize varieties showing stabilized resistance to Aphis gossypii Glover;there were 5 maize varieties showing stabilized resistance to Rhopalosiphum padi(L.);there were 3 maize varieties showing stabilized resistance to Helicoverpa armigera(Hiibner);Most maize varieties displayed the mid-level resistance to Conogethes punctiferalis(Guenee);there were 3 maize varieties showing stabilized resistance to Ostrinia furnacalis(Guenee).2.The population dynamics of the main maize pestsThe number of larvae of the main lepidopterous pests on maize ears were investigated in2015.Tthe result showed that the larvae number of O.furnacalis was raising after July and peaked in early September,then began dropping,and started a surge to early October;thelarvae number of Conogethes punctiferalis(Guenee)was raising after the middle of August,decreased lightly after the middle of September,then started to raise;the number of Helicoverpa armigera(Hubner)larvae peaked in end of August to the middle of September.The number of O.furnacalis and Conogethes punctiferalis(Guenee)larvae in 2015 was more than that in 2014,and the occurrence dates was earlier than in 2014.