A study on the species diversity and the annual dynamics of Scarabaeoidea insects in Mangshan National Nature Reserve, Hunan Province

In order to understand the species diversity and annual dynamics of Scarabaeoidea in the Mangshan National Nature Reserve of Hunan Province, systematic investigations and diversity analysis of Scarabaeoidea insects were conducted from May 2020 to April 2021 using three passive sampling methods: pitfall traps (PT), Malaise traps (MT) and flight interception traps (FIT); monthly dynamic changes of their communities were also monitored continuously. In this study, 4 246 scarab beetles belonging to 255 species across 7 families were recorded, among which 720 beetles belonging to 66 species from 5 families were collected via PT, 137 beetles belonging to 29 species from 4 families were collected via MT, and 3 389 beetles belonging to 160 species from 7 families were collected via FIT. The species diversity index, dominance index, richness index and evenness index were 4.097, 0.963, 25.98 and 0.731, respectively. Among them, the number of species and individuals of Scarabaeidae were the largest, accounting for 78.04% of the total number of species and 90.58% of individuals. The species diversity index, dominance index, richness index and evenness index of Scarabaeoidea in low altitude areas were significantly higher than those in high altitude areas, but there was no significant difference between middle altitude areas and high or low altitude areas. There were also some differences in community similarity among different altitudes: medium similarity between high altitude and middle altitude, medium similarity between middle altitude and low altitude, but medium dissimilarity between high altitude and low altitude. In addition, the results of monthly dynamic analysis revealed that the total number of individuals in Scarabaeoidea community gradually increased from January to June, and decreased significantly from August to September. From January to April and October to December, the number of individuals in Scarabaeoidea community was less than 6% of the total number of individuals in the year. The total number of species gradually increased from January, and peaked in May, accounting for 52.17% of the total species number in the year, and gradually decreased from June to December. This study fills a gap in the ecological research on Scarabaeoidea insects in the Mangshan Nature Reserve, providing an important scientific basis for the conservation of their diversity and the management of agricultural and forestry pests.