Analysis of insect community structure and diversity in Ejina Populus euphratica forest in Inner Mongolia

To investigate the current situation of the insect resources of Populus euphratica forest in Ejina and analyze the diversity of insect community in order to provide ecological basis for establishing the data base of the insect resources and protecting the P. euphratica forest in Ejina. From May to July 2023, the insect community structure and diversity of natural and different disturbance types of P. euphratica forest in Ejina were investigated and analyzed by using color plate method, Malaise net method, lamp lure method, sweeping net method and sweet and sour solution method. The results showed that a total of 182 973 insect specimens were collected, belonging to 12 orders, 170 families, and 793 species. Hemiptera, Diptera, Hymenoptera, and Coleoptera were the dominant groups, and the number of Diptera individuals was far greater than that of other orders, accounting for 52.434% of the total number of individuals, followed by Hemiptera at 21.134%. In the natural P. euphratica forest, the dominant groups in terms of individual numbers are Hemiptera and Diptera, the number of insect individuals showed the following order: Over-mature forest > young forest > middle forest > declining forest, the Shannon-Wiener diversity index (H′) was the largest in the middle forest, and the Margalef richness index (dM) was the largest in the Declining forest, the insect diversity index was the lowest in May, the number of phytophagous insects (16 752) and predatory insects (6 854) was the largest in the young forest. In the P. euphratica forests with different disturbance types, the dominant groups in terms of individual numbers were Hemiptera and Diptera, the number of insect individuals showed the following order: Grazing area P. euphratica forest > Tourist area P. euphratica forest > Farmland area P. euphratica forest, the Shannon-Wiener diversity index (H′) and the Margalef richness index (dM) were the largest in the Grazing area P. euphratica forest, the insect diversity index was the lowest in May, the number of phytophagous insects (7 846) and predatory insects (4 664) was the largest in the Grazing area P. euphratica forest. The results preliminarily revealed the diversity of insect species, quantity and community in P. euphratica forest, and provided ecological basis for further management of P. euphratica forest and pest control by understanding the dynamic changes of insect community in real time.