Fabulous Flies

Today is a fly special! OK, so technically only a few of these species is a member of the true fly order (diptera) but every single one has the word 'fly' in it's common name.

First up is a butterfly, a beautiful small tortoiseshell on some buddleia.

This is the 20th species of butterfly I've seen this year, all of them within 20 miles of home. Unfortunately the number of tortoiseshells has dramatically decreased over the last few years. The popular theory for this is due to the increase of the parasitic fly Sturmia bella. The fly lays its eggs on the foodplant of the butterfly larvae. The larvae accidentally eat the fly eggs and the fly grub feeds on the inside of it's host, eventually killing it when the larvae is full-grown or even pupating. 

I've seen lots of dragonflies lately but most are impossible to photograph as they fly so quickly. There are several that I managed to capture though- this first one is a common darter. 

This individual is an immature male- adult males are red. Indeed the lack of red on this individual suggests it might be teneral, meaning it has just shed its exoskeleton. The exoskeletons are necessarily hard and inelastic so in order to grow the dragonfly has to shed its exoskeleton. 

Another dragonfly I saw recently was this Southern Hawker. 

This too is an immature male. Male Southern Hawkers are often seen patrolling the edge of a pond or river where they fight away rival males. This is an inquisitive species and if you see one it may fly quite close to investigate you. 

Onto the dragonflies smaller relatives now, the damselflies. A recent damselfly sighting was of this red-eyed damselfly. 

This is a female and you can separate it from the small red-eyed damselfly by the length of the stripes- this species has shorter ones. 

I was amazed to see that this common blue damselfly was still able to fly with the obvious injury to it's tail.

This may well have happened when it was newly emerged as that point they are very vulnerable to strong rain and wind, and of course attacks by predators. 

Onto the proper diptera now! This is perhaps one of the country's most unpopular insects, a cranefly. They are also often known as daddy longlegs and they are plenty of other local names from them too. 

Cranefly is the common name of members of the 'tipulidae' family of which there are over 15,000 species. Most adult craneflies only have a lifespan of 10-15 days but often even that is not needed. Female crane flies usually contain mature eggs as they emerge from their pupae and are able to mate immediately if a male is around. The males spend their time flying and walking around looking for females to mate with. 

Here's an odd looking species of fly, Coremacera marginata:

This species is also known as the Sieve-Winged Snailkiller. Whilst the adults visit flowers, the larvae feed on snails, hence the name. Unfortunately, like most flies, there is very little information about the life cycle of this creature available. Flies are really fascinating insects yet are largely ignored or despised by most people.

Finally for today, this is a hornet mimic hoverfly (Volucella zonaria).

This is the largest species of hoverfly in Britain and does look fairly similar to hornets, though this species of course has no sting. I've seen many of these around this summer- hornets are usually seen in the Autumn. This was a rare species when it was first identified in the 1940s but it is now common in Southern Britain and is spreading North. The individual above is a male as the eyes touch- females have eyes which are more separate.