Identification And Insecticide Screening Of Aphid Resistance In Different Maize Varieties

To master in yenji around corn aphid occurrence regularity,screening effective except the aphid potions,doing theoretical basis for maize seed selection,promoting the five main maize varieties and 10 corn aphid harm degree of maize varieties with 15 maize varieties with different materials,investigate longjing field within the population growth of aphids number to determine distribution of dynamic,evaluate the aphid resistance of maize varieties;By measuring the content of main nutrients in different maize varieties in 4 periods,the relationship between the content of nutrients and the yield of maize aphid was analyzed.The living conditions of maize aphid were simulated to establish the life table of maize aphid in 15 different maize varieties.According to the results of laboratory and field experiments,the effects of 9 new insecticides on maize aphid were analyzed.The results are as follows:There were two peaks of aphid occurrence in maize field,namely tasseling stage and estrus filling stage.According to the resistance evaluation index,there is a huge difference in the number of maize aphis of different maize varieties.Five main maize varieties in yanbian state,pengcheng 1,are medium resistant varieties,rehe 228,jidan 27,pengcheng 216 are susceptible varieties,and pengcheng 6 is high sensitive varieties.The nutrient content of different maize varieties in different periods was different,and the content of reducing sugar in tasseling stage and soluble protein in leaves in filling stage were positively correlated with the occurrence of maize aphid.Different maize varieties have significant influence on the growth,development and reproduction of maize aphid.The lower the survival rate,yield,net proliferation rate,aphid life span,development period,weekly growth rate and internal growth rate,the more inhibitory effect on maize aphid,and the higher the higher the promotion of maize aphid reproduction.The longer the average age period and population doubling time,the worse the adaptability of maize aphid in maize varieties,and vice versa.The results of the indoor and outdoor tests showed that bifenulin cream had the best control effect,and the control effect reached 97.93%7 days after the drug was applied.The control effect of high chloro imidacloprid emulsion,thiamethoxam suspension agent and acaroid nitrile suspension agent can also reach more than 94%7 days after the drug,showing strong control effect,can be used in turn,in order to achieve better efficacy.Among the five main maize varieties in yanbian,pengcheng no.1 had the best aphid resistance,with lower nymph survival rate,fecundity,low net productivity,low intrinsic growth rate and weekly limit growth rate than other main maize varieties.Besides,the average generation cycle and population repopulation time were longer than other varieties.