Eristalis cryptarum


Eristalis cryptarum is a European species of hoverfly. Known as the bog hoverfly, it only lives in and around wet heathland and valley mires. Its larvae are assumed to live in peat that is saturated with water, such as that found in these boggy areas.
The female has been observed deposting eggs on and close to very fresh cow dung along oligotrophic seepages in moorland.
E. cryptarum has a wide distribution across central and northern Europe and East to Siberia and Mongolia.
In England, it was once found in all southwestern counties as far east as the New Forest, but since the middle of the 20th century its range has contracted, for unknown reasons, and it is only now found at a few sites on Dartmoor, Devon. In Denmark it is considered critically endangered, possibly extinct.

Description

For terms see Morphology of Diptera
Wing length 6·5–10 mm.Last antennomere reddish. Scutellum various shades of reddish-orange or yellow. Tergites 2-4 whitish pale hind margins. Pubescence mainly orange.Costal wing edge infuscate.Tibia 1-3 entirely orange.
The male genitalia are figured by Hippa et al. The larva is undescribed.