Enriching streetscape habitat for urban insects: A before–after‐control‐impact study in Melbourne, Australia

Residential road verges are an abundant and undervalued green feature in urban environments. As we strive to identify novel spaces for conservation in cities, there are opportunities to use the space afforded by residential road verges for habitat additions to support urban fauna.

We implemented a paired before–after‐control‐impact (BACI) experiment to assess the value of habitat gardens on residential road verges for bee, beetle, butterfly and moth biodiversity in Melbourne, Australia. These gardens were designed specifically for the insects known to inhabit the area and included resources for juvenile and adult nutrition, nesting and shelter.

Following the addition of habitat gardens, insect abundance was seven times higher on impact sites compared with controls, and species richness approximately doubled. However, this effect was not consistent across insect taxa: bees showed the greatest response, followed by beetles. We detected no response to the treatment from butterflies and moths.

The species richness and abundance of bees were positively associated with the species richness and cover of flowers in the habitat gardens, and native bees foraged consistently on flowers of Goodenia ovata, Wahlenbergia spp. and Brachyscome multifida .

Synthesis and applications : We demonstrate that habitat gardens on residential road verges can support a higher abundance and species richness of insects than a traditional lawn verge. As road verges comprise a substantial proportion of urban green space, converting lawn verges into habitat gardens represents a scalable and practical strategy for enhancing insect biodiversity in cities. As both landowners and policymakers, local governments are in a unique position to effect this change by encouraging or facilitating their residents to enhance the road verge. Considering the evidence in support of road‐verge habitat for insect biodiversity, these gardens could also be incorporated into municipal biodiversity strategies.