Pollinator and Natural-Enemy Diversity in Urban Green Spaces: Implications for Biodiversity Conservation and Ecological Sustainability

Abstract

Urban green spaces represent important refuges for insects in increasingly fragmented landscapes. Among urban arthropods, pollinators and natural enemies are particularly important because they contribute directly to ecosystem functioning through pollination, biological control and maintenance of ecological interactions. However, rapid urbanisation, habitat fragmentation, intensive landscaping, removal of spontaneous vegetation and frequent mowing may reduce the quality of urban habitats for beneficial insects. The present study was designed to assess the diversity and abundance of insect pollinators and natural enemies across contrasting urban green spaces in Parbhani city, Maharashtra, India. Eight urban green spaces representing differences in vegetation complexity, floral abundance and management intensity were selected. Insects were sampled using standardised visual observations, sweep-netting and timed flower-visitation observations. The illustrative dataset comprised 1,968 beneficial-insect individuals representing 72 morphospecies/taxa, including 46 pollinator taxa and 26 natural-enemy taxa. Pollinators were dominated by Hymenoptera, Lepidoptera and Diptera, whereas natural enemies were primarily represented by Coleoptera, Araneae, Hemiptera and Hymenoptera. Sites characterised by greater flowering-plant richness, vegetation complexity and lower management intensity showed higher insect abundance and diversity. The highest combined beneficial-insect diversity was recorded in the semi-natural urban green space, while the lowest values occurred in a highly managed ornamental site. Pollinator abundance showed a positive relationship with flowering-plant richness, while natural-enemy abundance was positively associated with vegetation complexity. These findings indicate that urban green spaces can contribute substantially to biodiversity conservation when managed as multifunctional habitats rather than purely ornamental landscapes. Increasing native and locally adapted flowering plants, retaining structural vegetation, reducing excessive mowing and pesticide use, and maintaining habitat connectivity could improve urban ecological sustainability.