Role of Habitat Change in Insect Diversity: A Comparative Study of Different Habitats in Dhapa, Kolkata, West Bengal, India
Résumé
Situated on the eastern outskirts of Kolkata, India, Dhapa offers a remarkable natural environment where agricultural operations, waste disposal, and naturally regenerating vegetation coexist. Although commonly perceived as a landfill, Dhapa sustains a mosaic of human-modified and semi-natural habitats that support considerable insect diversity. The study was conducted across three distinct sections of the Dhapa dumpsite—agricultural fields, mixed vegetation zones, and disturbed areas—to quantify insect diversity and assess habitat variation. The study of diversity of insects is very important to determine the number of insect species present in a particular area for conservation purposes, and pest management strategies are also fundamentally based on insect diversity. A total of 1,301 insect individuals from 10 orders and 55 families were documented between September 2024 and February 2025. The dominant order was Hemiptera (31.24%), followed by Diptera (20.31%) and Hymenoptera (20.01%). According to diversity indices, disturbed sites had the lowest values of species richness and Shannon diversity, while mixed vegetation had the highest values (d = 3.556; H' = 2.302). ANOVA verified that the three habitats' diversity differed statistically significantly (p < 0.05). Cluster analysis also revealed that while disturbed areas stood apart, reflecting the effects of anthropogenic disturbance, agricultural fields and mixed vegetation formed a close cluster due to their ecological smilarity. These results demonstrate the importance of vegetation complexity in forming insect communities and the necessity of combined waste management and conservation approaches.