Eristalis pertinax

Common name: Tapered Dronefly
Scientific name: Eristalis pertinax
Genus: Eristalis 管蚜蠅屬
Family: Syrphidae 食蚜蠅科、碧玉蚜蠅科, hover flies, flower flies
Suborder: Brachycera 短角亞目
Order: Diptera 雙翅目, true flies

Remarks: A large Eristalis, easily distinguished from the similar-sized E. tenax and E. simils by the orange coloured front and mid tarsi. E tenax also has entirely dark, swollen hind tibia and stripes of dark hairs on the eyes. Males of pertinax have particularly pointed (tapered) abdomens. 

The rat-tailed larvae have been found in farmyard drains and other organically-rich pools, though no doubt use a variety of water bodies including woodland pools and ditches.

Status: E. pertinax is a widespread, often abundant hoverfly that can be found in a wide range of habitats but perhaps especially woodlands and wetlands. It flies from March to November and visits many sorts of flowers. Spring males hover for protracted periods, seemingly defending small territories and can be especially noticeable in woodland rides and gardens in spring. Summer males hover much less frequently.

Date: 31st March (Female, Male) & 7th April (Male) 

Female:

(43) Female has much smaller eyes, placed farther apart.

(43_1) The presence of vena spuria (actually a fold rather than a true vein), the line cuts through the middle of the wing but then peters out, and the false margin, the veins don't extend out to the outer edge of the wing, makes hoverflies different from other flies. 

Note the presence of loop in the longest vein indicates that it belongs to a group of hoverflies whose larvae live in water and are called rat-tailed maggots.

39

(39_1) Note the orange coloured front and mid tarsi (blue circle) (vs black front and mid tarsi of E. tenax, common dronefly). Also note the half orange, half black coloured hind tibia (red circle) (vs entirely dark, swollen tibia of E. tenax, common dronefly).

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Male:

(196) (taken on 7th April) Male hoverfly has bigger eyes which come closer together at the top of the head. 

(195)  (taken on 7th April) Male Eristalis pertinax have a particularly pointed abdomen.

(76)

(76_1) Note again the orange coloured front and mid tarsi (blue circle) (vs black front and mid tarsi of E. tenax, common dronefly). Also note the half orange, half black coloured hind tibia (red circle) (vs entirely dark, swollen tibia of E. tenax, common dronefly).

(89)

(89_1) Note again the orange coloured front and mid tarsi (blue circle) (vs black front and mid tarsi of E. tenax, common dronefly). Also note the half orange, half black coloured hind tibia (red circle) (vs entirely dark, swollen tibia of E. tenax, common dronefly).

(96) Washing front legs?

(77) Washing the mid and hind legs?

(92) Washing the extended proboscis with front legs? 

(90) Busy washing front legs and proboscis? See how the proboscis is extended and retracted.