Black Darter

A trip up to Dartmoor yesterday to mess around in some ponds collecting some water samples. I found something that I had been looking for for ages - Black Darter (Sympetrum danae) exuvia:

I had a hunch that this was going to be danae but had to wait for it to climb up the stem and leave the exuvia. Actually ended up IDing the dragonfly from the exuvia as it was so young!

When it had hardened off a bit it was clearer that it was a danae.

The key criteria for the exuviae is the short length of the spine on segment 9 (S9) compared to the length of that segment. The ratio on this came out as 0.348 which is consistent with the spine being about a third the length of the segment.

The UK confusion species are S. striolatum (Common Darter) and S. sanguineum (Ruddy Darter). Never found sanguineum exuviae but there were plenty of striolatum for comparison yesterday.

Note the length of the spines compared to danae. The ratio came out at 1.114 on this one which is on the low side but the spine is longer than the segment so should be OK to rule out sanguineum which should be shorter. Also pretty sure that sanguineum does not occur in that area.

This is what the emerger might turn into if it is a male.

Moths

It has been a while since any moths featured here. Not had time for a huge amount of trapping this year but have done a bit over the last couple of weeks now the weather is better. Having started only last year and with last summer being rubbish, lots of new species have found their way into the trap. I'm also trying to start with micros but am only having limited success!

True Lovers Knot - possibly the coolest common name ever!

Burnished Brass

Double-striped Pug

Drinker

Barred Yellow

Plymouth Panoramas

The sound from Mt Edgecumbe

The sound from the top of Smeaton's Tower

Been playing with the new panorama function on the iPhone!!

The Weekday Biologist!

Time for a career change! Due to various bits of restructuring in the university, the department that I am in currently (Biomedical and Biological Sciences) will soon become two departments (Biological Sciences and Biomedical and Healthcare Sciences). That has left me in a bit of a quandry as to what to do and where to go but I have opted for (and been granted) the possibility to go with the new school of Biological Sciences. Kind of a career change but it means I can keep my human biology research interests and develop my biological interests further!!! Looking forward to new things and to leading the Biological Sciences degree programme.......

More on mimicry

You may remember last year I posted on Crypsis and Mimesis in moths? You might have guessed that I like mimicry! Yesterday while looking for bumblebees I came across this:

This is not what it looks like as it is the Hoverfly Volucella bombylans var. plumata which exhibits Batesian Mimicry. Batesian mimicry is all about looking like someone else for a variety of reasons (looking like someone who is toxic when you are not to fool predators for instance). For this Hoverfly, the reason is simpler but more devious as it clearly looks like a Bumblebee. The reason is that they manage to sneak in to Bumblebee nests to lay their eggs and the larvae feed on nest detritus. Indeed there are two forms, var. plumata and var. bombylans that look like Bombus lapidarius and Bombus leucorum/terrestris (below) respectively.