Friday mystery object #311 answer

For the last couple of weeks I’ve been offering up what has been affectionately nicknamed ‘cave snot’ for identification:

mystery311a

The initial goop was a bit too difficult to identify from a photo, so I dug in and pulled out the critter responsible:

mystery311c

This proved much more identifiable, with Chris immediately recognising that it’s the larva of a Caddisfly (not really a fly, but a more moth-like insect in the Order Trichoptera – which means ‘hairy wings’ as palfreyman1414 mentioned). Natalia Maas went one better by alluding to the family – the Philopotamidae or Finger-net Caddis, explaining the goop, which is actually made up of little silk nets shaped like fingers (hence the common name for the family). These nets are used to collect organic detritus and diatoms from flowing water, which the larvae then feed on.

I provided a couple of extra images to help narrow down the identification, since there are only five species in three genera of Finger-net Caddis in Ireland (and England for that matter), which are able to be differentiated from the anterior margin of their frontoclypeus (see the diagram below if you’re not sure what that is).

caddis-frontoclypeus

There’s an excellent website looking at Trichoptera in Ireland, descriptively called TrichopteraIreland, where you can find the details of how to tell the larvae of different genera apart, but the short version is to look at the frontoclypeus and if it has a deep U-shaped notch in it you have a Chimarra marginata, if it has a shallow V-shaped notch in it then you have Philopotamus montanus and if it’s a smooth curve then you have a species in the genus Wormaldia (which could be W. subnigra, W. mediana or W. occipitalis).

Unfortunately you can’t readily tell Wormaldia species apart when they’re larvae, so unless I’m missing a well-hidden notch in the frontoclypeus, we can’t identify this to anything better than genus level – but that’s still a substantial improvement on simply calling it cave snot.

I’ll be taking the specimen to the previous Entomology curator of the Museum, since his area of specialist interest is Caddis, so I’m sure he’ll be able to confirm the identification and I expect there may be some interest in where it came from.

More mysteries next week!

Friday mystery object #308 answer

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

mystery308

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).

640px-chlorion_aerarium_2_biml_usgs

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.

Friday mystery object #297 answer

Last week I gave you this shiny green beetle with white spots (and apparently a penchant for making balloon animals) to identify:

mystery297

I thought it might offer a bit more of a challenge, but I forgot about Google. It turns out that a Google Image search using the key distinguishing features provides some useful images to compare, making this easier than I expected.

As palfreyman1414 correctly recognised (followed by many others), this is the Spotted Flower Beetle Stephanorrhina guttata (Olivier, 1789).

Of course, when dealing with historic museum collections things are never quite that simple, so the specimen on display is actually referred to by the genus name Ceratorrhina which isn’t recognised today. Ceratorhina was synonymised with Cyprolais, which is a subgenus (containing the Horniman Beetle) that’s in the genus Eudicella.

Of course, that means that this specimen may have been named incorrectly in the first place, since I’ve seen nothing to suggest that Ceratorrhina has been directly linked to beetles in the genus Stephanorrhina which sometimes carry the synonym Aphelorhina in older collections information.

It would be interesting to work out how the incorrect name was applied to this display specimen, but I have an inkling that there was once a rogue curator who just liked to cause taxonomic trouble…

Friday mystery object #297

Happy Friday everyone! Once again it’s time for the mystery object and once again I’m in a different country and am relying on a photo I have on my phone to supply you with a specimen for identification. That means the photo isn’t ideal, but it does mean I have something a bit different from the usual skull or bone:

mystery297

Any idea what species this colourful insect and its less lovely larva might be?

As always you can put your questions, observations and suggestions in the comments section below. Have fun!