Study on the Two-dimensional Spatial Pattern of Monochamus alternatus Larvae
[Objective]It is to study the two-dimensional spatial distribution pattern of Monochamus alternatus larvae,so as to provide a scientific basis for the prevention and treatment of Monochamus alter-natus.[Method]The number of larvae on dead pine trees in different habitats was investigated systemati-cally.The spatial distribution patterns of larva in different diameter at breast height(DBH),height,altitude and slope direction habitats were studied by using four kinds of aggregation index method.[Re-sult](1)The larger the DBH and the taller the tree height,the more the number of Monochamus alterna-tus larvae gathered.(2)In dead pines with different DBH and height,Monochamus alternatus larvae ten-ded to gather,and the aggregation area moved upward with the increase of DBH and tree height.(3)No Monochamus alternatus larvae were found in the posts below 5 cm.(4)There was no significant difference in population density of Monochamus alternatus larvae in dead pine trees at different altitudes,but the number of Monochamus alternatus on dead pine trees in different slope direction showed a chan-ging trend as follows:south slope>west slope>southwest slope>southeast slope>east slope>north-west slope>northeast slope>north slope.Monochamus alternatus larvae in different altitudes and slopes showed aggregation distribution.[Conclusion]The two-dimensional spatial distribution pattern of Monochamus alternatus larvae on dead pine trees was mainly affected by DBH,height and slope direc-tion.For the control of Monochamus alternatus,corresponding strategies should be adopted according to these influencing factors,focusing on dead pine trees with large DBH,high tree body,so as to improve the control effect.