Sunday, December 23, 2018

You spin me right round, baby...

Many are the times that I've watched the surface of a patch of still water and pondered the madness of whirligig beetles.

What exactly are they doing as they perform their mad, gyrating dance. I guess it's probably a feeding strategy combined with a bit of anti-predator defence. However, I like to think they're just listening to some top tunes and dancing like no one is watching.

Anyway, with 11 species in the UK you simply can't ID one from watching it and so I'd never actually properly identified one, except to the general moniker of 'whirligig'.

Over the dark and wet days of the last few weeks I've been working my way through the backlog of unidentified beetles sat in my fridge. And lo and behold a whirligig had been caught in my moth trap one evening, giving me a chance to properly give it a name.

 After a couple of wrong turns in the key and some help on the UK Beetles facebook page, this keys out as Gyrinus substrisatus the most common whirligig in the UK and pretty much ubiquitous. The overall shape, colour of legs and especially claws point to this species.

However, a new species for me and the garden.
Here's a tune for the beetles....

Monday, September 24, 2018

Whipping out yer bits

It's the thing that those who look at beetles often fail to mention (although I often use it as a line at parties) - the fact that in order to identify many beetle species one has to examine the structure of the genitalia under a microscope.

It's taken me a while to dive in properly but now I've started I have to say that I'm rather enjoying it. And it certainly makes identifying many species just that little bit easier.

Take the staph genus Philonthus. There are about 46 species recorded in the UK and external characters only get you so far, especially if you don't have known reference material for comparison. However, find a male, whip out its bits (or in the case of a beetle, its aedeagus) then bob's yer uncle, much easier. Compare to drawings of known species and play match the nadger.

Each species has an unique key (the aedeagus) that fits the females reproductive tract (the lock). It's this that is one of the methods of speciation for many beetles.

For example, I found this particular individual on strandline material in northern Cumbria. I could only get it so far using the keys but the aedeagus immediately IDs it as P. carbonarius.

Another individual from this genus was collected from cow dung in Cambridgeshire in the early summer. The two red patches on the elytra are fairly distinctive but just be sure the aedaegus identifies this as P. cruentatus.

Another genus of staph Lathrobium. Relatively straightforward to get to that bit but once again the aedeagus confirms this as L. geminum.

And it's not just staphs that this is useful for. I found this Heterocerus mud beetle the same night as the aforementioned P. cruentatus but this individual had been attracted to the light of the moth trap we were running. I only got so far with the key and some of the features weren't that distinctive and I certainly wasn't confident putting a specific name to it. A quick root around and its family jewels confirm it as H. fenestratus a rather common beetle but one that I'm happy that I've identified correctly.......

Sunday, September 2, 2018

Some Spanish wildlife

Back at the end of July we took our family holidays in northern Spain, spending 2 weeks in Asturias.
A great time was had involving lots of rioja, wild swimming and salted pork products.
Butterfly numbers were down a huge amount form last year but there was still plenty to see.

A selection of goodies follows

Saturday, September 1, 2018

A tale of two histerids

Just down the road from me and within spitting distance of the River Cam is some rather uninspiring farmland.

However, it (and some of the vegetation around) hold a couple of rather good beetles, the leaf beetle Chrysomela saliceti and the histerid Saprinus virescens. For the chrysomelid I think it's its only known UK site.

Fellow moth-er and beetler, Bill had found a Saprinus during the week under some knotgrass - where they prey on the associated Gastrophysa polygoni, so I thought I should go and find my own.

I spent a good couple of hours poking about under all the knotgrass I could find but drew a blank. On leaving, I bumped into beetle expert and pan-species lister, Steve Lane who showed me one that he had found up the road in another field edge - untickable and in a pot but still nice to see.

Whilst there he took me through a hedge to the corner of another field where he'd found some good arable plants. All of which were new to me.
Dwarf Spurge Euphorbia exigua
Round-leaved Fluellen Kickxia spuria
Sharp-leaved Fluellen Kickxia elatine
I also saw this, which presumably must be Redshank Persicaria maculosa but doesn't seem 'quite right'.

Steve also mentioned a large manure heap back down the road that was heaving with Lesser Earwigs (cue a guffaw from the clued-up schoolboys) and the staph Astenus pulchellus.

Off I went and got sieving. Both species were easily seen and I also found the rather nice histerid, Atholus bimaculatus, which was a new one for me.

So I did end the day with a new histerid, just not the one I intended.

Sunday, August 26, 2018

In search of the Cliff comber

I've been wanting to go and have a look for a certain carabid beetle for a couple of years now and a last week I finally got my arse in gear and organised an after work trip with fellow beetler, Bill. Leaving home at 17.45 we arrived at Overstrand in NE Norfolk an hour before dusk (19:30).

The beetle in question was Nebria livida sometimes known as the Cliff Comber, a large and predatory ground beetle and a specialist of soft rock cliffs. Historically known from Norfolk to East Yorkshire it only appears to be hanging on on the soft cliffs either side of Cromer.

After beating a patch of Sea Buckthorn and attracting the attention of a couple of holidaying families who asked us what we were doing, we made our way down to the beach and headed east.

The habitat here is fairly dynamic with parts of the cliff collapsing each year, yielding new patches of bare clay. Other parts are quite well vegetated having had a number of years for plants to establish. There were also numerous fresh water seeps coming out the base of the cliff and it was here we would focus our search. 

Over the next 4 hours we found various beetles including Asaphidion pallipes, Platyderus depressus, Paranchus albipes and several species of Bembidion.....but no livida.

By 23:30 we were tired and still had a long drive home so we decided to call it a day.

We both felt like it needed another go, so last week saw a repeat trip out but this time to East Runton. The cliffs are steeper and there are far less water seeps and this time the weather was looking beautifully ominous.

However, after about 90 minutes of searching we came across a couple of isolated water seeps and lo and behold our quarry was there, hanging out at the top of the beach around these damp patches, waiting for whatever these beetles feed on.

They were absolutely stunning creatures and we counted at least 11 individuals over the next 20 or so minutes. It's good to see this species still hanging on here but the longer term forecast for them is less rosy. How much longer will they hang on.....

Thursday, July 12, 2018

Heatwave micros and a micro macro

I normally struggle to catch micros in the garden trap. I'm not sure why but the number and variety haven't been amazing over the years.

However, this recent hot spell has brought quite a few new ones to the garden including a few lifers for me.

Anarsia innoxiella

Zeiraphera ratzeburgiana

Gypsonoma minutana

Sciotia adelphella
Gypsonoma dealbana

and not a micro but just as small, a Kent Black Arches Meganola albula

Numbers have been spectacular and the numbers of grass moths are beyond count. Long may it continue!