Crane flies mating - September 2006

[Bruce Williams]

Hi folks,

Here's a couple of pics I took at the height of the UK crane fly explosion in mid September 2006 (2005 was bad too). This is a mating pair with the female on the right. She is recognisable by her lighter coloured abdomen, swollen with as yet unfertilised eggs.

The male genitalia has a pair of claspers which are used to grip onto the female's genital valves. The sting-like termination to her abdomen is in fact an extremely robust ovipositor. You can see that the male has to twist his abdomen through maybe 150 degrees in order to lock with the less flexible female.





If you haven't seen it already I recommend you check out Graham Matthews' recent posting HERE to see a close-up of the head and thorax.

Bruce
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[Ken Ramos]

Some very nice photographs Bruce, you did a good job on these.

[MacroLuv]

These two are working on explosion for sure.

[crocoite]

Now I remember one of the reasons I left the UK...These guys used to scare the bejeezers out of me when I was a kid.

Nice shots Bruce.

[beetleman]

Very nice DOF on these also. I have never seen a cranefly explosion. Why do you get an invasion of them in sept.? I only see a few here and there during the summer.

[Bruce Williams]

Thanks for your comments folks.

Doug, The high population of crane flies is primarily down to the unusually good weather conditions that the UK’s been experiencing in recent years. The female crane fly lays her eggs in soft earth (lawns, mud near open water etc). If the season is particularly dry the soil becomes too hard and fewer of the larvae (we call them leatherjackets) survive to become adult crane flies (they can’t get to the surface). The warm and damp conditions of recent years have been ideal for the leatherjackets, so crane fly populations have “exploded”.

I’ll have a go at photographing the leatherjackets later in the year.

Bruce

[Erland R.N.]

Good pictures. I see you were carefull to get both insects eyes in focus at the same time.
Nice info too. I usually see them hanging from a leaf or something, with one of them only hanging by the end of the abdomen. Wonder if that always is the female, in such circumstances.

Erland