Effects Of Landscape Pattern On The Abundance Of Cydia Pomonella And Crapholitha Molesta In Apple Orchards

The Cydia pomonella and Grapholitha molesta are the two most important pests in the apple orchards in Aksu area.The excessively simple landscape structure and the planting of a large number of host plants make the occurrence of these two pests become more and more serious,which seriously threatens the apple production in Aksu area.With the development of landscape ecology and integrated pest control,more and more attention has been paid to the research and application of landscape ecology in agricultural pest control.In this study,a random sampling method was used to investigate the population number of adult coda moth and pear microbivore in50 apple orchards in Aksu area from 2017 to 2020,and the landscape composition within a radius of 2km around the apple orchards was investigated.Then,a linear hybrid model was established for landscape variables and the adult population numbers of Cydia pomonella and Grapholitha molesta during the eclosion peak of different generations.The effects of different landscape structures on the adult population numbers of Cydia pomonella and pear pectoris during the eclosion peak of different generations were evaluated.The main results of this paper are as follows:(1)There was a significant or extremely significant positive correlation between the population number of the first generation adults and the proportion of apple area in the 0.5km,1.0km and 1.5km landscape scales.And 0.5km and 1.0km of other host plants,landscape fragmentation index(edge density ED)was significantly negatively correlated.And the edge density at 1.5km scale were significantly positively correlated.It was positively correlated with landscape diversity index at 1.0km scale and 1.5 km scale.There was a weak(P <0.1)negative correlation with 0.5km rice.Was negatively correlated with the area of other host plants at 0.5km and 1.0km scale.It was negatively correlated with other crop habitats at 0.5km,1.0km and 2.0km,and positively correlated at 1.5km scale.And 2.0km scale non-crop habitat was significantly negatively correlated.The number of adults in the emergence peak of the second generation was negatively correlated with the landscape complexity index(PARA),landscape diversity index(Shannon diversity index),the proportion of rice,and the proportion of other host plants at 1.5km.The population number of adults of the third generation was significantly negatively correlated with the proportion of rice at 2.0km scale.(2)There was a weak negative correlation between the number of adult population and the proportion of other crops at 2.0km scale in the eclosion peak of the first generation(P <0.1).There was a significant or extremely significant negative correlation between the population number of adults at the peak of emergence in the second generation and the proportion of planting area of other crops at four scales.And the Shannon diversity index(SHDI)at 0.5km and 1.0km were significantly negatively correlated.A weak negative correlation with 1.5km and 2.0 km;And 0.5km and 1.0km scale non-crop habitat area proportion was significantly negative correlation;And the proportion of orchard area at the landscape scale of 1.0km and1.5km was significantly negative.And 0.5km non-crop habitat area ratio was significantly negative(P <0.001);And Shannon diversity index(SHDI)at the same scale had weak positive correlation.There was a significant positive correlation(P<0.05)between the adult population size and the Shannon diversity index at 1.5km scale and a weak positive correlation with the Shannon diversity index at 1.0km scale at the peak of fourth generation emergence in apple orchard.The responses of the adult population of Cydia pomonella and Grapholitha molesta in different generations to the landscape variables at different scales were different.The adult population of Cydia pomonella increased with the increase of the proportion of apple planting area,but the proportion of apple planting area did not significantly affect the adult population of Grapholitha molesta.On the whole,increasing landscape diversity and the proportion of non-crop habitat area can effectively inhibit the damage of the two pests.