Climate-Driven Shifts in Urban Insect Diversity: A Comparative Study Across Green and Industrial Zones

Insects are communities undergoing changes due to climate change at the urbanising level but actual data from arid and semi-arid regions are limited. The aim of this study is to investigate the climate-driven changes in insect’s diversity in green and industrial zones of central and southern Iraq, using standard sampling methods by 10 sites in a year (2023), which include (January to December). A total of 8,847 insect specimens were collected from green zones that belonged to 8 orders, 42 families and 134 species. While in industrial zones 5,214 specimens were collected belonging to 8 orders, 31 families and 93 species. The Shannon-Wiener diversity index (H′) was 3.42 ± 0.18 for green zones and 2.18 ± 0.24 for industrial zones (t = 14.73, p < 0.001). The results of non-metric multidimensional scaling (NMDS) show that there were significantly different community assemblages among zone types. Green zones had a greater proportion of Coleoptera, Hymenoptera and Lepidoptera. However, industrial zones were largely dominated by Diptera and Blattodea. Pearson correlation analysis of temperature and Shannon diversity was found to have a strong negative correlation (r = −0.94, p < 0.001) in the green zones and (r = −0.97, p < 0.001) in the industrial zones while precipitation was found to have a strong positive correlation with species richness (r = 0.96 and 0.98, respectively). The community composition differed significantly (72.4%) based on the interaction between the habitat type and climate variables (PERMANOVA, F = 18.62, p < 0.001). The findings of this study show that the insect communities which are present in cities are vulnerable to the synergistic effects which occur due to climate warming and habitat degradation in arid urban landscapes.