Comparative study on community structural diversity of pests in pomelo orchard with different management modes

Abstract

In order to learn the community structural diversity of pests and temporal dynamics in different management modes of pomelo orchard, we selected abandoned pomelo orchard (AM) and traditional pomelo orchard (TM) to investigate the characteristics of pest community structure by netting, observation and sticky board trapping methods and classified and identified through the methods of morphology and molecular biology from May to October in 2020. The results showed that the amount of species was larger in AM orchard, while the individuals of pests were less than those in the TM orchard.The values of Margalef's index, Shannon-wiener index and Pielou index were all showed bigger in TM than those in AM, while the Simpson index was smaller, all of which with significant differences (P<0.05). The absolute advantage insects were Dacus dorsalis (19.75%), Dialeurodes citri (13.28%) and Lucilia sericata (10.15%) in TM orchard and Dacus dorsalis (75.87%) and Rhynchocoris humeralis (14.51%) in AM orchard. There was significant difference between the two community relative stability indexes (P<0.05). The similarity index of insect communities in both orchards was in the range of 0.18 to 0.40, which indicated moderately dissimilar to extremely dissimilar. The richness, diversity and evenness of insect community in TM orchard were bigger than those in AM orchard, which demonstrated that the ecological environment was more stable with more reasonable insect community structure and less particularly advantageous pest occurrences. This also indicated that it is important to utilize scientific management measures to create a harmonious and stable ecological environment, maintain appropriate diversity of ground cover plants, avoid abuse of chemical pesticides, build pest populations at reasonable thresholds and achieve the goal of improving quality of fruits and increasing income for planters. Keywords: Vegetation, Pests, community structure, diversity, ecological control.