Eristalini

Eristalis

DIPTERA > BRACHYCERA | Higher Diptera

MUSCOMORPHA > ASCHIZA > Syrphoidea > Syrphidae > Eristalinae > Eristalini

This is the first of two Eristalini tribe collections, which features some of the Eristalis species that I've photographed and have been able to identify.

Eristalis

There are ten species in the genus, although only seven are normally considered when trying to to distinguish the different forms. Six have widespread distribution right across the country, whereas the seventh, Eristalis rupium, is mainly an upland species that does not occur in the south.

All of the species I could and have seen, have certain features that aid identification, but most are pretty subtle and require an experienced eye and good photos to determine. Eristalis pertinax is regarded as the easiest to identify as the tarsi on the front and middle legs are yellow, coupled with a characteristic somewhat triangular-shaped tapered abdomen especially in the male. It is one of two larger species, the other being Eristalis tenax, which has a broad face stripe and eyes that in the right light can be seen to have vertical stripes of dark hairs, and together with those features has a curved and thickened hind tibia. Eristalis intricaria is a sexually dimorphic bumblebee mimic where the males are dark with a reddish-brown 'tail', whereas the females are larger and have a white 'tail'. Eristalis horticola is a much brighter species with a prominent dark mark across the centre of each wing, whereas Eristalis nemorum is notably darker and has a sharp-edged wing stigma. That leaves Eristalis arbustorum which, in my opinion, is probably the most difficult to determine, although it does have a diffused wing stigma that helps. I've had a couple of those where the id is non-conclusive and one where the similar, but not normally considered, Eristalis abusiva couldn't be ruled out.

The Eristalis species are often referred to as Drone Flies, with most having associated common names, such as the Common Dronefly (E.tenax), Tapered Dronefly (E.pertinax), Plain-faced Dronefly (E.arbustorum), Stripe-faced Dronefly (E.nemorum) and Stripe-winged Dronefly (E.horticola).