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Beetle blog

February 2013

Biodiversity Beetles in Focus

Posted by Blaps Feb 21, 2013

Here Tom Thomson, who is our lead researcher on the Coleoptera section's UKBAP project website, tells us a bit about the project and some of the interesting challenges of documenting Museum specimens! The UK Biodiversity Action Plan was first published in 1994, as part of the UK Government’s response to the Convention on Biological Diversity (CBD). It set out to describe the biological resources (including beetles!) of the UK in order to help conserve and aid recovery of species under threat or endangered. 


'Good day Friends, Romans and fellow Coleopterists!
An update for you on interesting and sometimes perplexing things encountered while working on many many lovely beetles from our collections as part of the Museum’s Biodiversity Action Plan species inventory of specimens and publication project (soon to be available on a scratchpad).


This project came about to address the balance in resources available to researchers working with these species all of which by definition are rare or endangered.  Many resources and organisations such as the  The National Federation of Biological Recorders (NFBR), and the NBN Gateway and other media often are unable to take account of the historical distribution of invertebrates of conservation importance through archive data.  Considering that within the NHM collections we have thousands of specimens going back to the early 19th century and beyond, (complete with specimen labels giving the distribution of species dating to a period before widespread habitat loss and pollution) this data is of incurable worth and highly significant. 


Knowing the present and historical distribution of a species is essential for any conservation work. In fact, many species are given conservation status specifically because they have declined, in many cases provable by the data available to ascertain if their present distribution is less than their historical distribution.  These former (wider) distributions can throw light on reasons for decline, and historic records may show modern day recorders valuable pointers for possible additional sparse populations of rare taxa, and estimate what their geographical limits might have been under more favourable conditions.


Of course the majority of information on the historical distribution of species is locked up in major museum collections and given the access possible via new online media is a great opportunity to bring ready transcribed label data, comprehensively checked and in a reliable form into open circulation from material that otherwise would often be difficult to interpret without expert curatorial assistance.
This often extremely cryptic data including collectors handwritten notes, habitat data and often multiple observations from generations of collectors and researchers on particularly old material is of international use and value and this projects’ main aim is to make this freely available to the whole conservation community for all UKBAP species of Coleoptera, to allow them to paint a more realistic picture of species’ distribution and status in the UK.


So onto the images that are an essential research to accompany this data, Well as many of you will probably know (and may well have some

experienced first-hand), getting high quality images of any small specimen is always a challenge, but something as complex and 3D as a preserved beetle (getting all the legs right up to the tarsi in focus particularly) can be more so than many things. Thankfully as technology is advancing fast in this area over recent years the better our computers and electronics in general become. For photographing most organisms we have moved on from manual cameras and spending long hours squinting down a view- finder fine focusing on tiny details; those days of developing negatives only to find that one diagnostic feature is blurred when you were sure it looked lovely and sharp when you took the image are now gone!



So the advent of a digital camera as a readily available tool both as compact pocket types with good inbuilt macro facilities right through to full digital SLR's with dedicated macro lens and the ability to connect directly to a computer is such a gift to us entomologists I am sure you will agree! The ability to operate things shack-free on remote right from the computer screen has really changed things for the better as well as being able to see the results in seconds not hours or days even more so!


In recent times, the biggest change of all is the advent of sophisticated software to combine images of differing focal lengths and merge them into a single smooth crisp image.  For some subjects this makes the previously impossible relatively easy.  Views of small organisms and their wider background are improved by being both crisp in focus, way outside the normal depth of field of even the best lens and far better quality than single images dodged and burnt on a film negative projector. The power to combine 20, 50 or even 100 images into one polished finished frame is priceless.  For imaging work possible with the more traditional methods, it can have its downsides when left on its automatic settings; combining frames as shot as demonstrated by this image below of the ground beetle Carabus intricatus.



These types of error are relativity easy to fix however, and this is the finished image:



Thankfully this is a rather drastic example! For the most part it’s a wonderful quick and smooth process with results like this:



Carabus intricatus dorsal view


This image took only 20 minutes with microscope and camera and less than this in the software.
The other end of the spectrum though is this fine specimen of Ampedus rufipennis in frontal view which is composite of 156 images and took around two hours to take with a similar amount to smooth and blend in the software.'




Let your love Glow…

Posted by Blaps Feb 13, 2013

Happy St. Valentine’s Day beetlers!


When we talk about love it’s a subjective thing, and often attraction is in the eye of the beholder. What attracts us to one thing more than another we cannot fully explain; but, what we can explain are some very specific and perhaps even artful methods of attraction employed in the beetle world. This St. Valentine’s we honour that most successful paramour of love, the Glow worm!


Glow worms are beautiful creatures, at least when they light up! However, upon inspecting our collection, I find it is quite hard to see them as being very attractive at all.



A rather uninspiring drawer of Phengodidae glowworms from our collection
Image courtesy of Helena Maratheftis 2013


Instead of investing their energies into metamorphosing into  the multifarious morphologies possible within the Coleoptera such as beautiful metallic colouration, impressive horns and armature,  clever methods of mimicry and disguise, they are in fact for the most part, small, soft bodied and brownish – in effect, not sexy; but perhaps a hidden nature is yet to be revealed! Yes, come cover of darkness, a mysterious transformation occurs, and what this drab exterior belies is revealed in all its brilliant neon glory!  Yes, glow worms glow!



Lampyris noctiluca courtesy of Devon Wildlife Trust



What is a glow worm?


Well you may have gathered by now that glow worms are not actually worms – they are beetles! Currently there are two families that could be considered glow-worms in popular understanding, the Phengodidae (which includes the famous ‘railroad worm’) and the Lampyridae (which includes the common European glowworm Lampyris noctiluca). The Rhagophthalmidae warrant a mention as formerly they were included as a subfamily within the Phengodidae – but the jury is out on their taxonomic placement. Let’s just say they are related, as shown by the bioluminescent organs found in the larvae which are known as star-worms). They will probably end up as a subfamily within the Lampyridae.


The term worm probably derives from the female of the species which in many of the glow worms, despite undergoing a full metamorphosis, remains in what we call a larviform state. She will resemble the larvae with the exception of possessing compound eyes, often a hardened plate covering the head and differ somewhat in the number and position of ‘lanterns’ – the paler segments that transmit bioluminescence.



Lampyris noctiluca from top to bottom: adult male, larviform female and larva
Image courtesy of Helena Maratheftis 2013


And the reason for this rather lazy metamorphosis? Well would you bother to get out of bed if you could make your bottom glow like a glow worm?! Probably not! There is no advantage, particularly in terms of energy investment for the female to produce wings, or even to have the ability or desire to feed as an adult. All she wants and needs is to mate; or if we want to be a bit more romantic about it, and in the sage words and lyrics of Girls Aloud (c. 2004) she is a ‘love-machine’.



Calyptocephalus fasciatus; Lampyridae type held in the Museum's collection - complete wtih magnificent antennae!
Image courtesy of Helena Maratheftis 2013

The mating game


Perhaps we are not always aware of how complex our mating rituals can be. In the ‘glowworms’ the bioluminescent function is a ‘come-hither’ signal to wanton males. Given that the females often-times will only have a maximum of two weeks, if that (please bear in mind everything written here is a generalisation for the purposes of description – these behaviours will differ between families, genera and species) in which to attract a male, mate, lay eggs and then die, all of this without even stopping for a bite to eat* timing and the ‘attractiveness’ of the signal is paramount!


The ‘signal’ – the bioluminescent pulsing or flashing is a kind of Morse-code-love unique to different species. Throughout most of England in the summer for example, the female Lampyris noctiluca can be spotted at dusk climbing low herbage in order to elevate herself and gain as clear a pathway to her prospective male as possible, then it’s all systems go and she starts signalling. This signalling will go on until she has successfully mated; sometimes she is not successful on the first night; we all know that feeling!


Fatal Attraction


*In some of the Lampyridae, in particular the genus Photuris, the adults do feed; and with a somewhat macabre intent. Females of the genus are little minxes often referred to as the ‘femme fatale’ firefly! They are able to mimic the signalling of other species, which lures unsuspecting males to their deaths! The Photuris females need a defensive chemical that is found in the male (it would make less evolutionary sense to eat one’s own species!) in order to repel potential predators. This chemical is only secreted when the beetle is attacked. By consuming this chemical (known as Lucibufagin) the female boosts her predatory defences and lives to mate with her own kind!



A very attractive male of the Pseudophengodes genus
Image courtesy of Helena Maratheftis 2013



Love glow


The ‘glow’ differs between species and can serve a different function. The glow in the larvae is almost certainly evolved to deter would-be predators (though the larvae are voracious predators themselves, enjoying the odd millipede or slug!). In the adults, both males and females can signal, but in some species it can only be the female that lights up. There are also different frequencies of signal that are species specific and some species will aggregate en-masse and signal in unison! Some species’ adults do not signal for mating purposes, rather as a warning to predators and instead use pheromones to attract their mate.


Bioluminescence is a chemical reaction producing a ‘cold light’ with no infra-red or ultra-violet frequencies, and is the most energy-efficient form of light that we know and it involves a good deal of attraction!   Luciferin is the substrate and Luciferase is the enzyme, in the presence of magnesium, oxygen and Adenosine-5 Triphosphate (ATP) (present in all living organisms) the chemical reaction takes place within the lanterns which are technically known as ‘photocytes’. ATP and Oxygen are really attracted to Luciferin but because Luciferin is quite small (only three rings of atoms) it becomes quite ‘energetic’ in the presence of these big guys, and ‘ejects’ its atoms, thereby releasing a whole lot of energy in the form of light. Whilst this is going on, Luciferase (a massive 10,000 atoms) is giving all the chemicals a lovely big hug (in effect the catalyst for the process). Once this is finished the Luciferase lets go of the spent molecules and looks around for some more, and so the process continues over and over again at lightning speed producing that wonderful romantic neon glow!.


Tenuous beetle trivia

Winston Churchill was once reported to state ‘We are all worms. But I believe that I am a glow-worm

When I think of glowworms here is the song that I like to sing along to in my head, or even out loud (simply replace the word ‘flow’ with ‘glow’)



These Bellamy Brothers were definitely singing about glowworms when they wrote these lyrics:


There's a reason for the sunshine in the sky

There's a reason why I'm feelin' so high

Must be the season

When that lovelight shines all around us…


So let your love flow (glow) folks and a Happy St Valentine’s Day from Team Coleoptera! XXX



There’s no greater fun than dressing up as your favourite beetle right?


larviform female glowworm1.jpg

Railroad worm Phrixothrix sp - larviform female! Note Railroad 'worms' also produce a red light on their heads!



We would like to thank Helena for her excellent images and her work volunteering for the Coleoptera section. Here is what she does in the real world!



Member since: Sep 15, 2009

I'm Beulah Garner, one of the curators of Coleoptera in the Entomology department. The Museum's collection of beetles is housed in 22,000 drawers, holding approximately 9,000,000 specimens. This little collection keeps us quite busy!

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