Field Investigation And Control Technology Of Spodoptera Frugiperda In Guangdong Province

Spodoptera Frugiperda is an important agricultural pest that FOA issued an early warning to the world in 2018.It has invaded China since the beginning of 2019,its harm has been found in many provinces of our country.Guangdong province is a suitable area for the growth and colonization of Spodoptera Frugiperda.The environmental conditions are favorable for the gtowth and reproduction of Spodopte ra Frugiperda.Therefore,effectively controlling the occurrence of Spodoptera Frugiperda in Guangdong Province will play a key role in preventing and controlling Spodoptera Frugiperda across the country.Based on the field investigation of the larva and adult of Spodoptera Frugiperda in Guangdong Province,this paper grasp the field harm and population density of Spodoptera Frugiperda,and provides technical support for the prediction and prediction of Spodoptera Frugiperda.At the same time,the parasitic effects of the two parasitoids were investigated,which laid the foundation for the control of Spodoptera Frugiperda by using the natural enemy resources.In this paper,we also studied the indoor artificial feeding technology of Spodoptera Frugiperda,summed up a set of convenient feeding method,and monitored the resistance level of several commonly used chemical agents to guide the scientific use of chemical pesticides in different areas.The main results of this work are:(1)Field investigation of larvae of Spodoptera Frugiperda in the fieldIn the field,larva is the main and the larva of different instar often mixed.The larvae from the 1st to the 3rd instar ate the mesophyll on the fresh leaves,while the larvae from the 4th to the 6th instar ate a large amount of mesophyll,causing m ore serious damage.Compared with the four survey sites in the Pearl River Delta,Huizhou is the least damaged area,Foshan is the most damaged area,and Guangzhou and Zhuhai are the middle.The main reason for the difference of hazard degree in different areas may be that the base number of imported insect sources is different,the level of drug use and control of farmers in different areas is different,and whether the local plant protection department guides the farmers in time in the critical period.(2)Sexual temptation to monitor the occurrence of adult Spodoptera FrugiperdaAccording to the results of adult sexual attraction monitoring,the average amount of trapping in the monitoring points was Foshan(153.9 heads),Meizhou(91.1 heads),Shaoguan(41.9 heads)and Maoming(14 heads)from high to low.According to the investigation,the population density of Spodoptera Frugiperda in the East,West,north of Guangdong Province and the Pearl River Delta r egion was preliminarily mastered,which provided support for the prediction of Spodoptera Spodoptera in Guangdong Province.(3)Investigation of natural enemy resources and their parasitic effectsTo investigate the natural parasitism of natural enemies.The survey results show that the parasite rate average of egg masses of yellow-eyed Trichogramma is 22.38%,The average of egg parasitism rate is 12.7%,that the parasite rate average of egg masses of the black egg wasp is 33.37%,The average of egg parasitism rate is 42.34% It shows that these two parasitic bees have ideal effects in controlling Spodoptera Frugiperda.the Parasitism effect of the black egg wasp is better than that of the yellow-eyed Trichogramma.(4)Research on indoor artificial feeding technology and feeding optimizationIn this paper,a set of practical,simple and low-cost indoor artificial feeding technology was explored.Sucrose,ascorbic acid,rapeseed oil,sorbic acid and other components w ere added into the feed.The average survival rate of larva is higher than 85%,and the average pupation rate and the average emergence rate of larva are close to 90%.On the basis of the above feeding technology,feed optimization was carried out from the aspects of different artificial feed formula,production process,temperature and humidity conditions,and the influence of oviposition medium on the growth,development and reproduction of Spodoptera Frugiperda.The optimal feed formula was 4.The larvae were most fond of food when the feed was heated for 20 minutes,The best temperature is 27℃,the best humidity is 70%,and the adults laid the most eggs on the powdery plastic paper.(5)Resistance monitoring of conventional chemical pesticidesIn Guangdong Province,we carried out indoor resistance monitoring of three commonly used chemical pesticides,methotrexate,chlorobenzamide and bromochlorfenitrile.It was found that the resistance of the population to methotrexate and chlorobenzamide was in the middle level;the resistance to methotrexate and chlorobenzamide was in the low level in Shaoguan,Foshan and Huizhou.In Maoming and Foshan the resistance of Spodoptera Frugiperda population to bromofenitrile was at a low level.The possible reason for the difference of resistance in different regions is the difference of resistance to insecticides in the source itself.According to the different levels of resistance in different regions,we should use different types of pesticides in a scientific way.