Tag Archives for insect

Friday mystery object #411 answer

Last week I gave you this (somewhat dusty) mystery object to try your hand at identifying:

I know that insects aren’t a frequent occurence on the blog, so this was a bit of an unfamiliar one for many of the regular Zygoma commenters. Of course, that didn’t prevent some astute observations.

Chris Jarvis immediately spotted that this is a wood wasp or sawfly, while palfreyman1414 flagged that it looks more like a fly (barring the long ovipositor). That’s because wood wasps, despite being members of the Hymenoptera, lack that characteristic wasp-waist that makes the Apocrita (the hymenopteran Suborder containing wasps, bees and ants) so distinctive.

Not a fly, but not really a wasp either

The Symphyta is the Suborder containing the sawflies and there are thousands of different species. However, narrowing it down wasn’t really that hard, since sawflies specialise in using their ovipositor to lay eggs in the stem of quite specific host plants and the only sawflies in this size range are in the family Siricidae, which are the ones that pick on trees (which is pretty interesting, since they form a symbiotic relationship with wood-digesting fungi in order to feed on wood as larvae).

Quite a big bug*

Of course, being insects, there are still around 150 to choose from, but between ruling out taxa that have adopted Batesian mimicry and those that are a very different size or shape, it becomes easier to narrow down the possible contenders – especially when you consider that this one turned up in Dublin, Ireland (although as pests of wood they can emerge from pine timbers a long way away from their point of origin – this one probably got into the Dead Zoo in some of the timber being used for our big decant project). The best fit for this specimen lies in the Genus Sirex.

When tryingto to distinguish between members of Sirex it’s important to pay attention to colour details of the legs and antennae. In this case it has red legs and black-and-red antennae. If you spend a while checking through the very helpful Sawfly GenUS resource you’ll find that the best fit for the mystery specimen is a female Sirex juvencus (Linnaeus, 1758).

Of course, the entomologists out there managed to figure all this out without any problems, both on Twitter and in the comments.

So well done to Jaswinder and Russell Stebbings for getting a species level identification – I would say that you got it right, but since I’m not an entomologist I think I should just be pleased that your more informed opinions happen to support my best guess. Thanks!

Stay tuned for another mystery object next Friday. Have a great weekend everybody!

*not a Bug – the True Bugs are Hemiptera and have nothing to do with this.

Friday mystery object #372 answer

First of all, I’d like to wish you a very happy and healthy 2020!

Last year I gave you this festive-looking beetle to try your hand at identifying:

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It was a bit of a tricky one to get to species, since beetles are notorious for their huge diversity, plus they can vary in appearance quite significantly within a species.

James Bryant recognised this as a member of the Buprestidae, which is a family of wood-boring beetles that are commonly known as Jewel Beetles due to their metallic and iridescent colours. In fact, the wing cases (or elytra)  of some of the most colourful of these beetles have been used in traditional beetlewing jewellery in the parts of Asia where they are found.

Going beyond the family, the identification katedmonson provided through a great cryptic clue was spot-on (assuming I understood it properly). This particular specimen is an example of Chrysochroa rajah Gory, 1840, but in the collection it is still labelled under the synonym C. chinensis.

This species is one of those with a wide distribution, several subspecies and a variety of different colours and patterns, which can make it hard to identify based on just an image of the overall body (or habitus as it’s referred to by entomologists). Just to give you an idea of what I mean, here’s an example of the same species in the National Museum, Prague:

Chrysochroa rajah from southern China. Photo by Hectonichus 2010

Blue and green form of Chrysochroa rajah from southern China. Photo by Hectonichus 2010

So well done to katedmonson for getting this tricky identification. Look out for another mystery next week!

Friday mystery object #344 answer

Last week I gave you this impressive insect to have a go at identifying:

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No scale for this, but it’s probably safe to say it’s bigger than you’d be comfortable with.

By not giving the scale I was being a bit mean by holding back a useful clue. This fly (as recognised by palfreyman1414, Richard Blackmore and joe vans) is around 45mm long, making it one of the biggest of its kind – its kind being one of the Asilidae or robber flies.

The species is from Australia and it’s called the Giant Yellow Robber Fly Blepharotes coriarius (Wiedemann, 1830). They’re active hunters that prey on other insects, grabbing them in flight and carrying them off to a perch where they suck out their victim’s internal organs. Nice.

Apologies for the short answer this week – I’m just in the process of installing an exhibition and this specimen is one that is going on display to represent the Diptera. Hopefully I’ll be able to share some images of what I’ve been working on next week.

Friday mystery object #336 answer

Last week I gave you this impressive beetle to try your hand at identifying:

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Now although it’s big and showy, beetles can be hard to identify because there are just so many of them and closely related species can be very hard to tell apart.

This one has distinctive elongated jaws that mark it as being one of the stag beetles (family Lucanidae), which narrows it down, although there are well over a thousand species in the family. This one is a little bigger than most and the jaws are relatively unbranched, with a cleft at the end of a relatively squared-off and downward deflected ‘antler’.

Those ‘antlers’ are used by the males to wrestle for access to females, who have much more sensibly sized jaws and are smaller. Effectively they’re doing the same thing as deer and this is a good example of how evolution can lead to similar trends in behaviour and even sexual dimorphism across very different animal groups.

I think this is Mesotopus tarandus Swederus, 1787 which is a species from West Africa that is becoming increasingly popular in the pet trade. It has slightly shorter ‘antlers’ than the other species (or possibly subspecies) in the same genus, M. regius.

As you probably know, I’m more familiar with vertebrate identification than insects, so I was fortunate to have my intern Esmeralda, who is a keen coleopterist helping narrow this down, although I’m pleased to congratulate jennifermacaire who was on the same track with her identification.

Another mystery next week!

Friday mystery object #334

Happy Friday 13th! This week I have another diminutive animal (it’s a little under 4mm long) for you to have a go at identifying:

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I’m all too familiar with what this is and I’m sure that some of you have been unlucky enough to encounter them before, so cryptic clues as to the identity of this insect would be appreciated, for the sake of those lucky folk who avoided the attentions of this wee beastie.

Friday mystery object #333 answer

Last week I gave you this insect to have a go at identifying:

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I decided that this didn’t need a cryptic answer, since species in the Order of insects that this belongs to can be quite tricky to identify. The Order is of course the Diptera as this has two wings rather than the four most insects have – that means it’s a true fly (as palfreyman1414 pointed out).

Those pointy but sturdy mouthparts (unlike the pointy and skinny mouthparts of things like mosquitoes) give the family that this fly belongs to one of their common names – this is a type of “dagger fly” in the family Empididae – which you can tell from the antennae structure (three segments with the segment at the end being the longest). That helps narrow it down a little, but after that it’s a case of checking against things like wing veination and pattern – note the black line along the back.

Very well done to Emmanuel and James Bryant who noted these features and hit upon the correct genus. This specimen is Empis stercorea Linnaeus, 1761.

This specimen is actually mounted on a microscope slide, which makes it look a little weird:

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The label gives us the species, the sex (female) and the common name of “Corn-fly”, which I’ve seen used for a variety of fly species, but not for one of the Empididae. A bit of searching shows that this name is an old one used for Empis sp. in US catalogues for microscope equipment and mounted insects in the 18th Century.

There’s also a circular mark bearing a Wyvern (a two legged winged dragon), which is presumably a makers mark, although I’ve not yet managed to track down who the maker is.

More mysteries next week!

Friday mystery object #315 answer

Last week I gave you this big bug to identify:

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I had a feeling it would be fairly straightforward for some of you, since insects as big as this are reasonably distinctive, and I was therefore not disappointed with the flurry of correct identifications.

The first with a correct identification in the comments was Chris, who hinted at the scientific name with this suggestion:

Trying to identify this Cic-sac? Tho phar, Tho good! (Excuth the lithp!)

On social media people made suggestions relating to the common name for the species, mostly pointing out that it’s very loud. Putting the various hints together gives you the Double-drummer Cicada Thopha saccata (Fabricius, 1803).

Cicadas are weird. They’re in the Order Hemiptera (the true bugs) and the Suborder Homoptera (although that’s disputed and it’s probably safer to say Auchenorrhyncha). Best known for being noisy and having some species with synchronised emergence times that vary between every year and up to every 17 years, or somewhere in-between depending on species and environment. They have widely spaced eyes and a blunt head that is pretty distinctive.

As jennifermacaire pointed out regarding cicadas:

According to Plato, “[This species] used to be human beings who lived before the birth of the Muses. When the Muses were born and song was created for the first time, some of the people of that time were so overwhelmed with the pleasure of singing that they forgot to eat or drink; so they died without even realizing it. It is from them that the race of the [these insects] came into being; and, as a gift from the Muses, they have no need of nourishment once they are born. Instead, they immediately burst into song, without food or drink, until it is time for them to die. After they die, they go to the Muses and tell each one of them which mortals have honored her.”
– Phaedrus

The implications of this is that adult cicadas have a general inability to feed, although this isn’t quite true, since adult cicadas may still feed on sap.

This particular cicada is Australian and is one of the loudest insects on the planet, able to produce a call of over 120 decibels – loud enough to cause permanent hearing damage if right up against a human ear.

The abdomen is fairly hollow in the males of these insects, creating a resonating chamber, but sadly the last segment of this specimen has fallen off, making it hard to be sure of the gender on the basis of the genitals. However, the males have a couple of resonating sacs behind the hind-wing that is missing from this specimen, suggesting that it’s a female.

As far as noisy neighbours go, these insects are an occasional disruption, popping up every 4-6 years and making a noise that is apparently similar to high-pitched bagpipes.

It doesn’t sound great to me, so I’m (not so) secretly glad that I only have to deal with dead examples of these fascinating insects.

More mystery object fun next week!

Friday mystery object #315

It’s been another week of working with the Dead Zoo insect collection for me, so I thought I’d give you one of them to have a go at identifying:

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A big bug  at around 135mm wingtip to wingtip

I don’t think it’ll be particularly difficult for some of you, so please try to offer cryptic suggestions if you know what is, to keep it challenging for others who aren’t as familiar with these impressive invertebrates.

Have fun!

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:

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

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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:

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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).

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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:

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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:

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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!