Eristalis tenax (Linnaeus, 1758)Nomenclature
Known as the "Drone fly", but this term may also be used to refer to any Eristalis species and sometimes, other bee-like hoverflies.Biology
The larva is of the "long-tailed", semi-aquatic type, living in organically enriched ooze such as the mud fringing eutrophic and/or polluted water bodies, the run-off from farmyard manure heaps, silage and slurry pits, sewage works, and even exudates from putrefying corpses. When mature, larvae leave to look for somewhere dry, often a little above ground, to pupate. In doing so they may travel tens of metres from the larval habitat and turn up in unusual places. Adults disperse widely and visit a wide range of flowers. Can be abundant in gardens. Adult females overwinter (not infrequently in houses), and occasional individuals can be seen during warm spells throughout the winter. As the first warm days of early spring arrive (in recent years, often in late February) they emerge, lay eggs and then die - resulting in an early peak in observations. The species is not then seen again until this generation of larvae have gone through their development and emerge, typically around June. Subsequent generations follow throughout the summer with abundance tending to increase so that they often become one of the most abundant visitors to flowers, such as Ivy blossom, by September and October. As winter approaches and frosts begin, fertilised females seek sheltered crevices in which to overwinter.Distribution
Widespread and very common but seemingly more coastal in northern counties of England and in Scotland. Markedly anthropogenic, a pronounced migrant and with a very long flight period.