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!