Native vegetation on bee and wasp reproduction in urban greenspace



by LORENZO CIOTTI

Native vegetation on bee and wasp reproduction in urban greenspace

"Pollinator welfare is a recognized research and policy target, and urban greenspaces have been identified as important habitats. Yet, landscape-scale habitat fragmentation and greenspace management practices may limit a city's conservation potential.

We examined how landscape configuration, composition, and local patch quality influenced insect nesting success across inner-city Cleveland, Ohio, a postindustrial legacy city containing a high abundance of vacant land. Here, 40 vacant lots were assigned 1 of 5 habitat treatments, and we evaluated how seeded vegetation, greenspace size, and landscape connectivity influenced cavity-nesting bee and wasp reproduction.

Native bee and wasp larvae were more abundant in landscapes that contained a large patch of contiguous greenspace, in habitats with low plant biomass, and in vacant lots seeded with a native wildflower seed mix or with fine-fescue grass, suggesting that fitness was influenced by urban landscape features and habitat management.

Our results can guide urban planning by demonstrating that actions that maintain large contiguous greenspace in the landscape and establish native plants would support the conservation of bees and wasps. Moreover, our study highlights that the world's estimated 350 legacy cities are promising urban conservation targets due to their high abundance of vacant greenspace that could accommodate taxa's habitat needs in urban areas." This is what researchers of the study Effects of urban greenspace configuration and native vegetation on bee and wasp reproduction, published on the Conservation biology: the journal of the Society for Conservation Biology, said in their retrospective.

The queen, extraordinarily prolific, has the task of laying eggs and ensuring the cohesion of the colony; it is the first to flicker among the queens raised by the family, it is larger than the workers and drones and provided with a quill, or sting, which it uses almost exclusively to kill the rival queens, her sisters, ready to flicker after her.

Unlike the workers, it lacks the apparatus for collecting pollen, the pharyngeal glands and the ceripar glands. The queen can live up to 4 or 5 years. In relation to her very intense reproductive activity, she has a higher metabolism than that of the workers, and has the heart corpora more developed, while the corpora allata are less developed than in the workers.

The males have only the task of fertilizing the new queens; they are larger than the workers but smaller than the queen; they have a much shorter ligule than that of the workers, and therefore are unable to suck the nectar from the flowers and lack the sting, the pollen-collecting apparatus, the pharyngeal glands and the ceriparous glands.