Population Dynamics And Light-trapped Behavioral Rhythem Of Three Key Species Of Lepidopteran Pests

This thesis focuses on Mythimna seParata,elioverPaarmigem andAgrotisy ypsilonIn,which are three species of Iepidopteran pests.With the hourly automatic searchlight trapping and systemic study on them,our work clarified their annual dynamic and the flight-to-light rhythm,and provided scientific basis for the accurate forecast and early warning of the their migratory population.The results are as follows:1.The research on flight-to-light rhythm of Mythimna separataAccording to our results in year 2014 and 2015,the numbers of armyworms M.separata trapped by light were 1150 and 2601,respectively,which show a large difference between years.The earliest emergence of armyworm in year 2015 is 13 days earlier than that in year 2014,in addition,compared with the year 2014,the maximum daily peak of armyworm trapped by lights in year 2015 was 41 days in advance.Meanwhile,the total number of trapped armyworms in 2015 was about twice more than that in 2014.The peak trapping periods of armyworms occurred after midnight,showing a single peak pattern of flight-to-light rhythm during 2:00-5:00 a.m..Especially,the amount of armyworm trapped by lights reached to maximum during 3:00-4:00 a.m.accounting for 17.3%of the total amount at night.2.The research on flight-to-light rhythm of Helicoverpa armigemaBollworm H.armigera is an important agricultural pest with the character of facultative migration.According to the research results in year 2014 and 2015,the numbers of cotton bollworm trapped by light were 14152 and 19006,respectively.The total amount of trapped bollworm in year 2015 was obviously more than that in year 2014,with an increase of approximately 34.3%.The earliest immergence of bollworm in 2015 was 71 days earlier than that in 2014,in addition,compared with 2014,the maximum daily peak of bollworm trapped by lights in 2015 was 69 days in advance.The flight-to-light rhythm of bollworm belongs to single peak pattern during 1:00-4:00 a.m..In 2014,it was 2:00-3:00 a.m.when the amount of pest trapped by lights reached its peak,accounting for 23.65%of the total amount.While in 2015,it was 1:00-2:00 a.m.when the amount of pests trapped by light reaches its peak,accounting for 18.49%of the total amount.The peak trapping periods of cotton bollworm occurred after midnight,indicating a single peak pattern of flight-to-light rhythm.3.The research on fiight-to-light rhythm of Agrotis ypsilonAccording to the research,the total number of black cutworm A.ypsilon trapped by lights increased from 181 in 2014 to 326 in 2015 by 80.11%.The maximum amount of this pest on July 22th,2014 was 43,and the number on June 8th,2015 was 38.The earliest emergence date of black cutworm in 2015 was March 1sth,which was 124 days earlier than that on July 20th?2014.The single peak pattern of flight-to-light rhythm in black cutworm appeared not obvious,although it reached peak during 3:00-4:00 a.m.,accounting for 35.36%of the whole amount.It showed a typical single peak pattern of flight-to-light pattern in the year 2015,with the black cutworm trapped by lights centralizing during 2:00-5:00 a.m..And the amount of pests trapped by light reached peak during 3:00-4:00 a.m.accounting for 17.79%of the total amount.