The Biodiversity Of Arthropod Communities In Macleaya Cordata And The Adaptation Mechanisms Of Spodoptera Litura (Fabricius) To Macleaya Cordata

Macleaya cordata during its growth process is often fed by insect pests,which seriously affect its yield and quality.In order to understand the structure and variation trend of the arthropod community in the field,this research carry through a systematic investigation for Macleaya cordata fields over three consecutive years,from 2015 to 2017;to provide an important theoretical basis for the comprehensive management of insect pests and ecological control.According to the survey,the Tetranychus cinnabarinus(Boisduval)and Spodoptera litura(Fabricius)occupied the growth effects of phytophagous pests for those three years continuously.The dominant species of natural enemies and spiders were Chrysopa pallens(Rambur)and Tetragnatha Squamata Karsch.In 2015,the index of arthropod diversity in the Macleaya cordata field was the highest,with the largest number of species and the smallest number of arthropod individuals.In 2016,the total number of arthropods was the largest,with the lowest number of species and the lowest diversity index.The indicators were in the middle at 2017.There were no significant correlations between the number of order,family,species,individuals,dominant concentration,diversity and evenness of arthropod in Macleaya cordata field with the rainfall and average temperature during the survey period.Compared with the artificial feed control group,the activity of Acetylcholinesterase(AChE),Glutathione-S-transferase(GSTs)and Carboxylesterase(CarE)in the S.litura(Fabricius)were increased,and the content of Cytochrome P450(CYP450)was increased.The activity of AChE and GSTs and the content of CYP450 at the 4th instar were the highest,and decreased at 5th instar.The activity of CarE increased with the increase of fed time.The results of the experimental group were highly significant different from the control group.The results fully indicated that these four detoxifying enzymes are involved in the metabolic detoxification process of S.litura(Fabricius)for active ingredient of Macleaya cordata.Trehalose is the blood sugar of insects and the energy source for insects.The activity of Trehalose in S.litura(Fabricius)enhanced with the increased of instar from the 1st instar to 6th instar,decreased during the pupal stage.The trehalase activity of S.litura(Fabricius)fed by Macleaya cordata in different instar was lower than the control group fed by artificial diet at the same time.There was a significant difference in trehalase activity between the two groups during the same period in the 5th and 6th instar larval stages of S.litura(Fabricius).The results showed that Macleaya cordata can inhibit the growing development of S.litura(Fabricius)by inhibiting the trehalase activity.