Tuesday, January 26, 2021

The Necromancer and the Dented Clown

Last week, there was a dull thud at the front door as a parcel was pushed through the letter box and hit the floor. On investigation I was met with a copy of the new Histerid and Siphid Atlas

The authors have done a great job with this book and it is so much more than an atlas. Yes, there are up to date distribution maps but there is also natural history information, colour plates and brand new keys in there. The authors have also assigned English names to all species, something that I think is to be commended. Of course I will continue to use the scientific binomials but having some easy to access names make public engagement for these beetles so much easier when you can give people an English name.

Some will hate them and there will always be debate, but having beetles such as the Undertaker (Nicrophorus humator) and the Red-spotted Mucker (Atholus bimaculatus) will go a long way in helping to tell the story of how important these groups are in their ecology of clearing up the shit and dead stuff. 

I have found previous histerid keys a bit hit and miss and so I was looking forward to taking some beetles through the new key. I remembered that I had a couple of specimens in the fridge that I had extricated from a dead Lapwing at Chippenham Fen back in Spring 2018 but that I had not yet confidently put a name to. Out they came and under the microscope they went,

I rattled through the key pretty quickly. The specimens were similar (both had two stria at the edge of the pronotum and 3 full and one almost full elytral stria) but different (size and the punctuation on the back end). 

I soon realised that I was looking at the genus Margarinotus and that these were either M. striola or M. brunneus, both reasonably common and widespread. The two differ in the shape of the stria on the front of the head and whether they have a distinct fovea or pit on the elytra.

So the larger of the two (8.5mm) shows a an interrupted semi circular stria on the head (and no elytral fovea) making this one Margarinotus brunneus aka The Necromancer!!

The smaller beetles (6mm) has a more angulate head stria that looks like it slightly dips in at the front (although that is tough to see in the pic)

It also has a big fovea over the base of the third and fourth elytral striae making this one Margarinotus striola aka The Dented Clown!

So on one dead Lapwing I have the Necromancer and the Dented Clown. That could be the title of my next sci-fi book or possibly the name of a 90s indie band. Either is plausible.

So it looks like the keys might work (he says... fingers crossed). The book is a great addition to an ever expanding beetle library. 

Monday, January 25, 2021

Smallest staph yet

At only 1.3mm in length, this staph is the smallest of its kind that I have put a name to so far. It really is at the limit of my (and most definitely my microscope's) ability to see and dissect. Carding the specimen ends up being more of a wing and a prayer than anything else.

I sieved this from my compost heap at the start of the month alongside a whole load of ptilids that are also testing my ability for fine needlework.

It is Oligota pumilo and luckily it's tarsal formula (4-4-4) and it's clubbed antennae help get one to the rough ball park...

The male aedeagus (as is often the way) is pretty much a clincher.

If only I was having better luck with the ptilids!

Friday, January 22, 2021

I think I'm trapped here for a while

I hadn't really left the house much this week and being stuck inside was really starting to get to me. A look at the forecast was all the incentive I needed to make a quick plan for a temporary escape. So, I started today with an early morning walk down a stretch of the Great Ouse in the north of my Parish and coincidentally my 5MR area. It was the last bit of local river to walk where I thought there was a chance of finding Panageus cruxmajor. I have walked several miles of waterway since mid December looking at areas that have been grazed and have not turned up a single bloody one!

There just isn't the woody debris on the banks in comparison to where it is found along the Trent, further north. It's under this debris that others have found it regularly in Lincolnshire.

It didn't really matter, it was a stunning morning anyway and it was good to be out, improved by the fact that I didn't see a single other person for the whole time I was out. The surrounding fields were hooching with several hundred feeding Whooper Swans, with several parties flying over as I walked the embankment. I flushed three species of heron from the washes including a Great White Egret. I still get a kick out of seeing these despite them being regularly seen around the village. I am always reminded that these were still a mega when I started birding in the early 80s.

For the first part of my walk I was followed quite closely by an inquisitive herd of cattle. They eventually got bored and went off to find some decent grass along the washes.

I looked under every single bit of reasonably sized debris I found...

 ...but these bits were few and far between and my quarry failed to materialise. I think that's probably it now for this year. I could try other stretches further north but that would be a bit irresponsible during lock down so it will have to wait for next year. I did however manage to find a few other beetles to keep the year list ticking over. There was a single Paranchus albipes under a large mat of rotting vegetation, which is the first one I've caught in the parish.

On closer inspection of the vegetation there were also several staphs including this species of Sunius which I've still got to get to species.

There were also quite a lot of these small water beetles that I assumed would be Hydroporus but are actually Noterus clavicornis. Despite being an incredibly common species of water beetle it is the first time I've found this one. Mainly due to my lack of water beetling. So i did end the morning with a new species of beetle after all 😊

I've got an aleoch and Lathrobium still left to ID. I feel a need for a quick tussocking session coming on so will see if I can find a decent site within the 5MR. Here's hoping.

Wyclef and Mary J provide the post's title. I love this song, especially the bit where Mary J channels Marge Simpson. Enjoy.

Monday, January 18, 2021

What do you do when you're falling?

Having seen this recent post by Seth about the whole 5MR concept I thought it would be interesting to see what mine looked like. i.e what does a five mile radius (5MR) around my house encompass and could it provide some light natural history relief during lockdown?

Using the free map tools website, I decided to take a look.

So there I am just north of Cambridge, on the edge of the Fens and south of the Isle of Ely.

Zooming in you can see that the bottom of my 5MR circle is crossed by the mighty A14 that runs from Birmingham to Felixstowe, with the northernmost bit of the City of Cambridge to the south of it. The A10 also runs through it too, bisecting the eastern part, as it heads northwards towards to the Norfolk town of Kings Lynn.

But what about the habitat? 

The above satellite map shows a mass of agricultural fields interspersed by smaller pockets of housing. Pretty much most of the immediate land surrounding me is arable with the odd smattering of livestock. Not surprising really given the fertile nature of the soil around here. But what about the decent sites I (semi) regularly visit in search of beetles and other stuff?

So I decided to plot of them on the map to illustrate. 

1. Wicken Fen -  Very famous. The first nature reserve owned by the National Trust and according to the NT website it's one of Europe's most important wetlands, and home to over 9000 species. BUT at 7 miles from my house, not within my 5MR...

2. Wimpole Park Estate - another NT property and one with some great veteran trees and dead wood, plus lots of dung from cattle and sheep. BUT not within my 5MR...

When I look at beetle records on NBN I tend to find that for many species the only Cambridgeshire sites with records are the above 2 sites. So looking on the positive side I probably wouldn't be adding much by visiting those two sites, although I did add a new Wicken species a couple of years ago when I caught Badister collaris whilst moth trapping. 

3. Quy Fen - about 70 acres of common land that I only 'discovered' last year. It has some nice old oaks in open pasture and some dead wood. Also some nice bits of water. BUT just outside my 5MR...

4. Ditton Meadows - this has the closest bit of decent winter tussocking I've so far found. Common land next to the River Cam that regularly floods. I recorded 40+ species in 30 mins there just before Xmas. But guess what? Yep, not within my 5MR...

The final two sites I sometimes visit for a walk and incidental beetling

5. Fen Drayton RSPB Reserve - not within my 5MR...

6. Ouse Fen RSPB Reserve - not within my 5MR...

So it looks like I may have to be a little more inventive at finding some new sites to record in. 

There's my garden, obviously and there's a Local Nature Reserve in the next village where I've found a couple of nice things in the past. But I'm really going to have to scour the OS maps for hidden sites and gems. There is the River Ouse to the north, but having walked that whole stretch recently I don't hold out huge amounts of hope there. There's also a stretch of the River Cam to the east, most of which I know fairly well, but will have to see if I can make more of it.

Apart from that who knows, more to come on this I suspect....

Post title comes from Mike Oldfield

Friday, January 15, 2021

When is a tarsal segment strongly bilobed?

So, this garden Stenus from last April had me going round the houses a bit. I found it by suction sampling a patch of lawn which was more moss than grass and it was with two other species of Stenus.

Looking at the key to subgenus, there were no distinct raised margins to the abdomen which took me to a couplet about whether the fourth segment of the hind tarsus was strongly bilobed.

I thought it looked pretty bilobed, so off I went to subgenus Hypnostenus where I got confused. But if I assume it’s only slightly bilobed then it keys to subgenus Tesnus and straight to S. brunnipes and the aedeagus backs that up. The other features of raised head between the eyes and brown legs fit too.

So I guess there is a lesson here somewhere about the variation in bilobedness of tarsal segments but I'm not sure what it is yet...😆

Sunday, January 10, 2021

The streets are filled with debris...

 ... well, not the streets exactly, more of the fields surrounding the River Ouse just north of our village.

Having spent most of yesterday gardening, we decided to tear the kids away from screens and do a six mile loop around our local fenland today. What was underwater 10 days ago was now just wet, and more importantly covered in a fair amount of flood debrisand I took a couple of bags of it back home with me. The first sieving revealed three species of invert and the rest of the debris is now in my extractors in the shed awaiting perusal over the next couple of days.

First up was the most commonly encountered of the inconspicuous ladybirds, Coccidula rufa

I also found this Tachyporus which keys to T. chrysomelinus. It has the much longer hairs on the sides of the elytra. It's a common one but not one I've recorded before, so if confirmed is the first new beetle of 2021. Ten whole days.... better pick the pace up.

There was also this interesting bug which at 5.5mm stood out somewhat. I assumed it was a nymph and so appealed for help. I soon got an ID and it's one I could have got to myself had I made the effort (note to self!). It's in fact an adult Ischnodemus sabuleti  aka the European Cinchbug. There are two distinct common forms, one with short wings (micropterous) the one that I found and also one with long wings (macropterous). They have been expanding north over recent decades but it was entirely new for me.

On my return home, a quick look at the compost heap revealed lots of ptilids and tiny aleochs which I mostly ignored but did take a few for future examination. There was also one of my favourite garden beetles doing its thing in the dried grass. Mycetaea subterranea aka the Hairy Cellar Beetle.

The post title comes from the opening line of one of my favourite albums from 2020. It's the opening and title track from Keeley Forsyth's debut album, Debris. A stunning creation and well worth a listen.

Thursday, January 7, 2021

That mystery aleoch

In the last post I mentioned that I had picked up a mystery aleoch whilst sieving moss in a woodland. I finally took a look at it today. It's been almost a week but what with lock down, being back at work and the dreaded home schooling I've just not got round to it. 

Anyway, enough excuses. When I looked down the miscroscope I was met with this

I usually just turn to the key but there's no need with this one despite being only 2.3mm in length. It's one that is reasonably frequently encountered and can be identified without reference to the dreaded key.

Overall it's quite pale and has small eyes.When you look closely you can see a couple of small bumps on the elytra (circled below). The central base of the pronotum is also flattened and sticks out a wee bit.

This specimen is a male and there is also a small keel to be found on the fifth visible tergite too (circled below). 

These features make this Geostiba circellaris. It's a common one and I guess could potentially be ID'd in the field although my skills aren't currently quite there yet! 

Saturday, January 2, 2021

A slow start to 2021

I decide to kick of the year's beetling by visiting some of Cambridgeshire's ancient woodland.

Boy, it was hard going. There were springtails in abundance but I struggled to find many beetles. It was very wet underfoot which meant that the usual tactic of finding carabids under logs failed miserably as they had all either moved or drowned!. 

Sieving leaf litter and moss turned up very little of interest and I only managed to find five species in total. I found the ubiquitous Tachyporus hypnorum and T. dispar plus a mystery aleoch that will need a closer look.

The fourth species of staph I found was this Rugilus orbiculatus

Turning over one piece of well rotted oak, I found several of these surprisingly large larvae hiding amongst the detritus.

I'm pretty sure they are Pyrochroa serraticornis aka the Red-headed Cardinal Beetle.

I suspect a visit to the compost heap will be needed to properly kick the 2021 beetling year off. On the plus side I only have one specimen as homework :)