The Fluctuation And Growth Characteristics Of Two Migrator Pests And Evaluation Of Control Efficency By Different Plant Protection Atomnzing Mechiney And Pestoides In Chongming District

Rice crops are the major staple food with high economic importance.Due to the' factors like change of rice paddy farming system,the comprehensive promotion of straw reapplication,and climate change,recent years have seen frequent occurrence of Cnaphalocrocis medinalis and rice planthopper,posing severe threat to rice yield(Liu et al.,2008).At present,around 25 000 hm2 of rice cultivation area lies in Chongming District.The proper protection of against insect pest is critical for rice production and to meet local demand.Nowadays,chemical pesticides remain the primary option to control Cnaphalocrocis medinalis and rice planthopper in this area.However,the long-term use of chemical pesticides will pollute the environment,disrupt the ecological balance,and induce insect resistance to insecticides(Zou et al,2014).Meanwhile,underdeveloped plant protection equipment leads to low utilization rate of pesticides and undesirable control effect.To explore high-efficiency,low-toxicity and low-residue insecticides and environmentally-friendly strategies,the occurrence characteristics of the two insect pests from 2010 to 2016 were analyzed,and the control effects of different plant protection machinery as well as the control effect of frequency-vibrating insect-trapping lamp on two insect pests were evaluated.Additionally,the screening test of high-efficiency,low-toxicity and low-residue insecticides were conducted.The results were described as follows:1.The fourth to fifth generations of Cnaphalocrocis medinalis occur annually in Chongming area,with the fourth(2),fifth(3)and sixth(4)larvae as the main devastating generations.The accumulative moth population of Cnaphalocrocis medinalis in Chongming area varied significantly from 2010 to 2016,with the fifth(3)generation as the most,followed by sixth(4)generation.When the daily number of moths is the most,the daily average peak number is also relatively higher.During 2010-2016,the number of Sogatella furcifera migrating in Chongming was the largest,followed by the Laodelphax striatellus and the Nilaparvata lugens.The annual migration of S.furcifera varied significan,with the third(1)as the most immigrant generation.The third(1),fourth(2)and fifth(3)generations were the major immigrant generations.Since 2011,the immigration of the Laodelphax striatellus declined year by year.Recently,the immigration of N.lugens was significantly lower than of the L.striatellus and the S.furcifera,and there was no significant difference in the number of immigrants among different years,with the highest number in sixth(4)generation and the lowest number in third(1)generations.2.The control effect against Cnaphalocrocis medinalis and rice planthopper of agroforestry spraying rotorcraft showed that the efficacy of rotorcraft on Cnaphalocrocis medinalis and rice planthopper was the best as the control effects on Cnaphalocrocis medinalis and rice planthopper reached 90.7%and 61.6%respectively 14 days post application of insecticides.The rotorcraft has high control efficiency,premium quality,no harm to crops,and promising prospect in specialized prevention and control of diseases and insect pests on crops.3.The frequency-vibrating insect-trapping lamp has excellent control effect on Cnaphalocrocis medinalis and rice planthopper,with the average control efficacy reaching 68.6%and 72%respectively,which dramatically reduced the number of insect sources and had a certain degree of lure-killing effect on other rice pests.Moreover,it has no adverse effects on natural predators,hence it can be a potential alternate to pesticides.4.The screening test of insecticides for Cnaphalocrocis medinalis and rice planthopper control showed that 10%tetrachlorocarbamide and 20%methyl-indenocarb had better control effect on Cnaphalocrocis medinalis,and the corrected control effect reached 97.5%and 95.7%respectively 12 days after treatment;while 50%nitenpyramide,20%furosemide,10%chlorothiazole and 22%fluorine had better control effect on rice planthopper.An overall above 83%control effect was achieved for all these insecticides post 15 days.Therefore,these insecticides can be used as ideal control means for Cnaphalocrocis medinalis or rice planthopper,and should be popularized in large scale.