Southern Marsh Orchids

Southern Marsh Orchids

Sunday 6 April 2014

Beetles, a bug and coastal species

I've just replanted a lavender hedge in my back garden and kept half an eye on what emerged while pulling the old one out.  The first thing that caught my eye was a very attractive little Rhopalid bug, Corizus hyoscami.  Unfortunately it flew off before I could get a good photo so here is one from the nice people at Wiki Commons:
Author: H Krisp Link Licence

 It is a species which seems to be doing well, in recent years it has been expanding out from the south coast of England, but has a very coastal distribution in Wales
Distribution of Corizus hyoscyami in the UK according to records accessible through the NBN Gateway
C hyoscami distribution
I also found three Carabid beetles, two from the relatively small Leistus sub-genus which contains just 5 british species.  First was Leistus spinibarbis, easily recognised by it's metallic blue iridescent colour and the heart shaped pronotum (the bit behind the head).

Leistus spinibarbis
One of the defining characteristics of L spinibarbis according to the RES handbook is that the first few segements of the antennae are a darker colour than the rest.  None of the specimens I have seen from this area show that feature, but other microscopic features show it nonetheless to be that species.

Next up was a beetle that I hadn't seen before, which caused me some confusion in reaching an id.  It had key features which pointed to another Leistus species: heart shaped pronotum, exposed outer edges of the mandibles and a ventral setral cage (the setral cage is a very characteristic arrangement of stiff hairs of the lower surface of the jaws which is used in capturing its prey, usually collembola).  The colour patterns (dark head and pronotum, paler elytra and pale legs) however didn't match any of the british species.  After a bit of help from Steve Bolchover (gratefully received - thanks Steve!), I have concluded that it is a teneral (freshly emerged) example of Leistus ferrugineus.  Teneral beetles are often much paler in colour, and as you can see from the pic below, the elytra (which are a bit squished) are still quite soft.

Leistus ferrugineus

Distribution of Leistus (Leistus) ferrugineus in the UK according to records accessible through the NBN Gateway
L ferrugineus distribution

It is quite common in England,  but again with a marked coastal distribution in Wales. 

 The final carabid beetle was one of the smallest british species, Microlestes maurus.  It is approximately the length of a sesame seed (about 2.5mm), but much narrower.  Once again I have gone to Wiki Commons for a pic:
Microlestes maurus
Author:Udo Schmidt, Germany
Link  Licence

Distribution of Microlestes maurus in the UK according to records accessible through the NBN Gateway
Microlestes Maurus distribution

 This species has very few Welsh records from scattered coastal locations in Glamorgan, Gwent and Gwynedd.  Once again they are all coastal sites!

It would be interesting to know whether its diminutive size leads to under-recording compared to other carabid species or if it is genuinely uncommon in a Welsh context. 


  1. Classy bug, Adam. The best I could do today was a Green Shieldbug and a Willow Warbler.

  2. Yes, it's obviously not too bothered about standing out - presumably must have some chemical defence mechanism!

  3. Nice beetles Adam. I've done a little work on carabids in the past but haven't seen any of those 3 species. I haven't done much at the coast, though I did do some surveys at Barry Docks which produced a nice range of species.

  4. I imagine Barry Docks would have a fantastic range of rare invertebrates George, in some ways it's a shame most of it is going to be developed. I wonder if there are any mitigation plans?

  5. Hmm yes I was involved in surveys relating to the development, but that was 5 years ago - there was certainly mitigation planned then, but I've no idea if things have changed in the meantime.

  6. Bother these obscure dark creepy crawlies skulking around in the debri. What good are they doing? What ecosystem service are they providing for us? He says with heavy irony.

    First queen Tree Bumblebee over the year in my garden in Bridgend @ lunch-time, nest finding. With this weather set fair, I would be surprised if most will not see one this week-end, or into next week, if you have not already.

  7. A good question Nigel. I think it was it Oscar Wilde who defined a cynic as someone who knows the price of everything and the value of nothing - very apposite!

    On a more positive note, there was a lovely little Hairy-footed Flower bee in the garden this afternoon, at least I think it was that species - the only one with a cream-coloured face?

    There were also quite a few Carder bees nectaring on Lithodora which seems to be the plant of choice in my garden at the moment. Is there an easy way of telling them apart?

  8. Yes, and I have not seen any carder bees yet this season. Head and thorax looks very carder bee like very glossy brown with perhaps a hint of orange, but the thorax is jet black, and for the individual this morning it took a couple minutes to even notice the white tip to the abdomen.

    If you get well marked workers later on, I have always thought we could called them the tricoloured bumblebee because they are simple brown black white from front to back.

    If any of your carder bees are obviously partly black it would be a good candidate for hypnorum, in fact it has to be.

    You could probably get 3 brown carder bee species in your garden, common (with black hairs on the thorax); brown banded (with only black hairs around the wing bases) or moss (no black hairs at all anywhere). And as red shanked carder bee occurs at East Aberthaw, along with the previous 3, you probably might get that as well, which is a red-tailed bumblebee look alike (very un carder bee like) but has red hairs on its legs.

  9. Thanks for the tip Nigel. When the sun is out next I will pot one or two up and see what we have!

  10. Yesterday I was regretting what I had suggested on Friday weather wise, but today should be really good for pollinators as long as you have suitable nectar sources, as you have with Lithodora