Wednesday, 13 August 2014

A few common or garden flies

12th August 2014 - Topsham


I know they can be a nuisance, I know some of them spread diseases and I'll admit many have rather unsavoury lifestyles but take a close look at a fly and tell me they're not amazing. I've been pottering about the garden with my macro lens and, as usual, it's been mostly flies. Conditions haven't been perfect but occasionally the sun goes in (photos of shiny insects in bright sun look dreadful) and the wind drops (with exposure times of 1/5 second you don't want the subject moving at all). Here's a few mostly common species, all named using the appropriate identification keys.

Lucilia sericata Calliphoridae - 12/8/2014 Topsham
This is a common greenbottle (also known as the sheep blowfly) Lucilia sericata. Identified by the pale basicosta (that whitish nubbin at the base of the wing) and, as it's a male, by the widely separated eyes (Erzinçlioglu 1996). There are seven British species of Lucilia and this is one of only two which are safely named from a photo, for the rest you're going to need a male specimen and a microscope.

Eristalis tenax Syrphidae - 12/8/2014 Topsham
Here's a very common hoverfly Eristalis tenax, also known as a drone fly as it's a honey bee mimic - even down to the fake pollen baskets on it back legs. Identification is pretty straightforward based on the broad black stripe down the face and vertical bands on the eyes (Stubbs & Falk 2002).

Scathophaga stercoraria Scathophagidae - 12/8/2014 Topsham
Another easily recognised species, this is the common yellow dung fly Scathophaga stercoraria, safely told from the other nine British Scathophaga spp. by the conspicuously black antennae (Ball 2007).

Nemorilla floralis Tachinidae -12/8/2014 Topsham
This one, a parasite fly or Tachinid, is rather less straightforward to identify. It does show the general appearance of the family - strongly kinked medial wing vein, 'delta wing' posture and it's strikingly bristly; another useful pointer is the slow purposeful hunting flight when searching for a host (in this case caterpillars) in which to lay its eggs. I've photographed this species a few times in the garden over recent years, identified using Belshaw 1993 and confirmed by the experts at diptera.info.

References

Ball, S.G. 2007; Key to the British Scathophagidae (Diptera), Version 3.1
Belshaw, R. 1993. Tachinid flies. Diptera: Tachinidae. Handbooks for the identification of British Insects. Royal Entomological Society of London 10, Part 4a(i).
Erzinçlioglu, Z. 1996; Blowflies. Naturalists' Handbooks 23. The Richmond Publishing Co.
Stubbs, A.E. & Falk, S.J. 2002. British Hoverflies. British Entomological and Natural History Society.

3 comments:

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  2. With a strong interest in diptera myself, I enjoyed this post and how it was constructed.

    Not seen Nemorilla florialis so I shall be looking out for that one.

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