Effect of Urbanization on the Diversity of Beetle Families in and around Aizawl, Mizoram

An increase in urbanization and anthropogenic activities has led to a decrease in the area covered by forests which has an impact on the ecosystem and the diversity of flora and fauna. Coleopterans are a group of insects which are known to play an important role to study the impact of urbanization as they act as bioindicators. A study was conducted from September 2018 to October 2019 to determine the effect of urbanization and forest size on the beetle diversity in selected sites representing urban, semi-urban, and rural areas in and around Aizawl, Mizoram. Collection was done by setting up light traps as well as manual collection and other standard methods on a bi-monthly basis. A total of 445 beetles belonging to 15 families were collected. Identification of beetles was carried out only upto family level. Beetles community showed a significant variation in different degrees of urbanization as abundance and species diversity of beetles declined with increasing urbanization in different sites. In terms of the total number of individuals collected, the family Scarabaeidae was the most dominant (21.35%), followed by Cerambycidae (19.77%) and Lucanidae (11.91%) with the highest numbers collected from rural sites. The soil parameters were analyzed which showed a significant correlation with the forest size and this, in turn, affects the beetle diversity. Overall, the diversity of beetles (diversity index, richness, and abundance) is found to be affected in such a way that it is higher in rural sites as compared to urban sites.