Syrphid Fly

Syrphid Fly (Eristalinus aeneus)

Eristalinus aeneus is a medium-sized hoverfly measuring 8-12mm in length, characterized by its metallic bronze-green thorax and distinctive large eyes with vertical stripes. Like other syrphid flies, adults are important pollinators that feed on nectar and pollen, while their aquatic larvae develop in stagnant or slow-moving water bodies where they help decompose organic matter. Adults exhibit typical hoverfly behavior, remaining stationary in flight while visiting flowers, and often mimic wasps or bees as protection from predators.

This species demonstrates one of the broadest global distributions among syrphid flies, occurring across Europe, North America, Asia, Africa, and Oceania. It inhabits diverse environments from urban areas to agricultural landscapes, typically near water sources such as ponds, ditches, and wetlands where larvae can develop. The species shows remarkable adaptability to various climatic conditions, from temperate to subtropical regions.

Despite its extensive range, Eristalinus aeneus faces classification as Endangered, though specific threat assessments remain incomplete. The primary concerns likely relate to widespread habitat degradation, particularly the loss and pollution of freshwater breeding sites essential for larval development. Agricultural intensification, urban development, and water management practices may be reducing suitable breeding habitats across its range.

Current conservation measures for this species are limited, reflecting broader gaps in invertebrate conservation planning. The species benefits indirectly from wetland protection initiatives and pollinator conservation programs in some regions.

The outlook remains uncertain due to insufficient population monitoring data. While the species' wide distribution suggests some resilience, the Endangered status indicates significant conservation concern requiring targeted research and habitat protection efforts.

The distribution of this species is cosmopolitan. [https://www.inaturalist.org/observations?place_id=any&subview=map&taxon_id=154762 inaturalist map]