wasp | Zygoma

There are lies, damn lies and statistics* and then there are inaccurate statements made from assumptions that are based on insufficient knowledge and poor research. Last week I fell into this sort of untruth when I offered up this diminutive mystery object that I said was from Ireland:

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My excuse for that untruth is the fact that the specimen was in a part of the collection dealing with native species (which I forgot also includes British taxa, because the collection is old enough to have been split into “native” and “foreign” before Ireland stopped being part of the UK) and I’d quickly checked the distribution with reference to a handy online checklist of British and Irish Hymenoptera, but I then missed the bit under the species that said the range was restricted to England. I assumed based on context and as a result I got it wrong – and we all know that we should never ASSUME, because when you ASSUME, you make an ASS of U and ME*.

So thanks to jennifermacaire and David Notton for pointing out my mistake – it is much appreciated. I should have checked the label for the collection locality, but unfortunately the image was taken as a snap on my phone while bagging the drawer containing this specimen (while I was preparing hundreds of of other such drawers and insect boxes as part of a major collections move) so I didn’t get the chance. This is actually a bit of a problem for digitisation when insects are pinned like this, because the label is invisible from above.

Insect boxes bagged for transport and freezing

If I was more familiar with the insect fauna of Britain and Ireland it would have helped, but as you may be aware, my main area of experience is in bones and the critters that have them, so my knowledge of insects tends to be quite generalised or restricted to particularly important or interesting species that I’ve had reason to research.

Skull of female Jaguar in the Dublin Dead Zoo

The kind of specimen I really understand

This is one of the challenges in my role as curator of Zoology and Entomology at the National Museum of Ireland, where I work with somewhere in the region of 2 million specimens, covering the whole of the animal Kingdom, from all over the world.

Normally museums with collections of this size would have a few specialist curators to focus on the main taxonomic divisions, but for the time being I’m dealing with the lot, so I have a steep learning curve to get up to speed with the whole collection. Of course, it’s well worth it, as there are some incredible specimens in there – either because of what they are, or who they were collected by and how important they are for science and culture.

Wasps collected by Charles Darwin during the Voyage of the Beagle.

Anyway, excuses aside, I expect you’re keen to find out what that small hymenopteran was. Chris very quickly identified it as one of the small, solitary carpenter bees. This is the only one that is “native” – in that it occurs in Southeast England – and even then it’s pretty rare to find it except in downlands in the South, mainly in East Hampshire.

The name is Ceratina cyanea (Kirby, 1802) and the female excavates a burrow in the stem of a dead plant, making tiny cells with walls of sawdust in which she lays eggs – hence the name “carpenter bees” for the group that shows this behaviour.

Another mystery object to come next week – this time it will hopefully be a bit less misleading!

*Attributed to Benjamin Disraeli, by Mark Twain

*I’m attributing that to the fictional character Dawn Summers from Buffy the Vampire Slayer because that’s where I heard it first, but it was coined by Jerry Belson

Last week I gave you this beautiful insect to try your hand at identifying:

From the start it was pretty clear it’s a wasp (just look at that characteristic waistline) and palreyman1414 pointed out the key things to look for in making sure it isn’t a fly pretending to be a wasp:

I believe that there are some flies that are camouflaged to look like wasps, but a close look suggests that this thingy has a full complement of four wings, instead of the two plus two halteres (?) that characterises the flies

Now there are a LOT of wasps out there – somewhere in the region of 150,000 species (more than all of the vertebrates put together) so that doesn’t narrow it down much. However, that waist isn’t just pinched-in like your average wasp, it’s petiolate (that’s science-talk for “stalked”), which means it’s one of the Sphecidae.

The large size also helps – most wasps are tiny, so big ones like this are relatively scarce, especially bright metallic green-blue jobs. This distinctive appearance brings to mind for me the Steel-blue Cricket Hunter (see below), but it’s from the wrong part of the world (and it’s more green than blue).

Chlorion aerarium from Maryland, USA, July 2012. Image by USGS Bee Inventory and Monitoring Laboratory

However, we know there are a lot of wasps, so it’s worth looking at close relatives in the Sphecidae, to see if there is anything from the right part of the world (that’s made reasonably easy by using an appropriate reference with a checklist).

It turns out that we don’t need to look too far, as the mystery specimen looks like it’s in the same genus of Cricket Hunters – Chlorion (as suggested by Ilyas) and checking out the species occurring in India has me leaning towards Chlorion lobatum (Fabricius, 1775), which is what abcdefg200 hinted at.

These active hunters don’t eat Crickets themselves, they actually get their energy from nectar, so they’re helpful pollinators. The Crickets face a more grisly fate than just being killed and eaten – they are paralysed, then buried alive with a wasp egg laid on them, which subsequently hatches and the larvae eat the still-living Cricket. Nightmare fodder.

There are a few subspecies of this particular species of wasp, but I’m not even going to try to work out which this might be, since even carrying out a proper identification to species would require time with a microscope and a lot more experience than I have with this diverse, fascinating and above all nightmarish group of insects.