Effects Of Landscape Pattern On The Population Dynamics Of Apolygus Lucorum(Meyer-Dür) In Aksu Area,Xinjiang

Apolygus lucorum(Meyer-Dür)is an important polyphagous pest that cause damage to many crops,such as cotton and fruit trees.Apolygus lucorum has spread to many areas of Xinjiang since 2014 when it’s infestation on crops was first reported in Changji Prefecture,which may pose a great threat to the production of fruit and cotton in Xinjiang.It is the primary basis to innovate and develop regional governance countermeasures to find out the law of the growth and decline of the A.lucorum population in the farmland landscape system and its regulation mechanism.Based on the agroforestry complex ecosystem in the Aksu region of southern Xinjiang,this paper adopts the large-scale research method of landscape ecology,starting from the scale of fields and landscapes,to clarify the transfer law of the A.lucorum between different habitats,and to analyze the impact of habitat composition and layout on the Effects of the population dynamics of A.lucorum in cotton fields and jujube orchards.On the field scale,periodic community surveys were conducted on 56 major plant habitats by the sweeping net method to clarify the law of host transfer.On the landscape scale,26 cotton fields and 16 jujube orchards were selected,using The yellow board trapping method was used to monitor the population dynamics of A.lucorum adults,and the landscape composition and configuration within a 2 km range around cotton fields and jujube orchards were investigated on the spot.Effects of farmland landscape pattern on the population dynamics of A.lucorum in cotton fields and jujube orchards of different generations.Finally,by analyzing the correlation between the yield of cotton and the population density of A.lucorum in each generation,the influence of A.lucorum on the yield of cotton and jujube was evaluated.The main results of this paper are as follows:The regularity of seasonal host transfer of A.lucorum: Habitat survey found that The first-generation adults of the A.lucorum started in jujube orchards as early as the end of May.The host plants outside the jujube orchard were Ziziphus jujuba,Glycyrrhiza uralensis,Chenopodium album,and Brassica napus,etc.;In late June,the occurrence of the second-generation adults in the jujube orchard reached its peak.The host plants outside the jujube garden are Melilotus albus,Melilotus officinalis,etc;in early July,the second-generation adults migrated into the cotton fields,and then the third-generation,fourth-generation,and fifth-generation adults continued to damage the cotton fields.The host plants of the three-generation adults outside the cotton fields from early July to early August were Melilotus albus,Melilotus officinalis,Brassica napus,and Polygonum avicular,etc.from early August to early October,the host plants of the fourth and fifth generations of adults outside the cotton fields are Artemisia caruifolia and Artemisia argyi,etc.The effect of farmland landscape pattern on the population density of A.lucorum in cotton fields:(1)The proportion of cotton area was significantly negatively correlated with the population density of the second generation of A.lucorum in cotton fields,and the area ratio of jujube was significantly positively correlated with the population density of the second generation of A.lucorum in cotton fields;(2)The area proportion of semi-natural habitats(including hedgerow)was significantly negatively correlated with the population density of the third generation of A.lucorum in cotton fields.There was a significant positive correlation between the population density of A.lucorum;(3)The proportion of cotton field area was significantly negatively correlated with the population density of the fourth generation of A.lucorum in cotton fields,while the area ratio of jujube trees,the area ratio of other crops(including maize),and the edge density had a significant positive correlation with the population density of the fourth generation of A.lucorum in cotton fields.Effects of farmland landscape pattern on the population density of A.lucorum in jujube orchards:(1)There was a significant positive correlation between edge density and the population density of A.lucorum in jujube orchards first generation;(2)The edge density was significantly negatively correlated with the population density of the third generation of A.lucorum in jujube orchards,and the area ratio of semi-natural habitats(including hedgerow)was significantly positively correlated with the population density of the third generation of A.lucorum in jujube orchards;(3)The marginal density was significantly negatively correlated with the population density of the fourth generation of A.lucorum in jujube orchards.Effects of the population density of A.lucorum on the yield of cotton: The population density of the first,second and fourth generation adults of A.lucorum was significantly negatively correlated with the yield of the central cotton field,A.lucorum mainly feed on young leaves in cotton fields.Adults of A.lucorum mainly prefer to feed on cotton growing points,young leaves,young buds and other tissues,which can have a greater negative impact on yield.