The date in the title of this post marks the sad passing of one of the Museum’s tiniest volunteers: in early February I discovered Beetah, my Carabus violaceous, lying still on her coconut substrate and to be honest, a little dried out.
My little pet worked hard in life to inspire the public with entomological wonder of what living gems can be found in local parks, let alone the wider world, so I think it’s only fair to take time and reflect on her life and service upon her passing.
This Carabus violaceus specimen was collected live while Hillery Warner was taking a walk in Nonsuch Park with her 1½ year old son, Dominic on 29 August 2013. Dominic christened the specimen “Beetah” on the spot and it was kept as a family pet until its death of natural causes in early 2015, at which point it was brought to the Museum to join the collections on 11 February 2015.
Beetah led a lavish life for a ground beetle, feasting on fish cakes and the finest chunks and jelly from packets of cat food. She apparently reproduced while in captivity and two of her offspring are also in the collection. While not an official front of house Museum employee, Beetah wore her public-engagement-purple elytral margins with pride, inspiring visitors at Science Uncovered 2013 and 2014. She also acted as an entomological ambassador during National Insect Week, 2014 where she met artists and UK celebrity Jonathan Ross. While the lights have left the multifaceted ommatidia of her compound eyes, she may yet “see” another Science Uncovered as she continues her service to the Museum in death as she did in life, entering her new role as museum specimen.
I found my beetle back in 2013 in a park near my home while walking with my then 1 ½ year old son. As I keenly showed my son this lovely large black beetle with iridescent purple pronotal and elytral margins, he enthusiastically named it ‘Beetah’ and I detected some bonding going on, so I decided Beetah would live with us as a pet. I initially added a snail or two to her tank but soon discovered she was much happier to dine on my husband’s fish cakes. In fact, she ate so much fish cake that I noticed not long after that single meal that she had plumped up so much that her plural suture stretched enough that the underlying membrane was showing. I thought she was just fat.
Some time later there were a number, (at least 5), carabid larvae running around the tank (I’m sorry I called you fat, Beetah). How did this happen with just one beetle? In short, it didn’t, but insect reproduction is amazing and entomologists never pass up an opportunity to talk a bit about genitalia!
The christening of “Beetah”: Almost as good as the whole Mofasa/baboon/Simba thing from that ’90’s movie.
Female insects have an internal genital structure called a spermatheca. Upon mating, sperm is stored in the spermatheca rather than going straight to the eggs for fertilisation. The release of sperm from the spermatheca is under hormonal control and so the female can wait until conditions are ideal for reproduction before releasing the sperm from this structure to fertilise her eggs. This could mean waiting to find a suitable insect host for a parasitoid wasp, or finding enough fish cake to suitably supply the eggs with nourishment for pet Beetahs’. Lady insects have quite a lot of control over this and scientists have reported carabids going for as long as 10 months without contact with males before ovipositing (Gilgado & Ortuño, 2012) and honey bees can store sperm for over 3 years (Gullan & Cranston, 2000).
While both mother and larvae enjoyed cat food, I noticed that the larvae were active and fed during the day while mum was nocturnal. (I often described having a pet carabid like having a 6-legged carnivorous hamster due to the audible night time scrabbling sounds coming from her tank). This division of activity surely reduces the likelihood of intraspecific predation in nature. (Metamorphosis is a generally fantastic strategy to reduce intraspecific competition). I won’t comment on what happened to the larvae. Truthfully, I don’t know for sure (ref. 1). I’ll just let the mystery be.
Not long after that exciting event, Beetah began her work as and Museum volunteer. Her first public outreach event was Science Uncovered, 2013 where she assisted Dr Eggleton and Dr Inward in delighting the public with the wonders of soil associated invertebrates. In 2014 she participated in both a second Science Uncovered and National Insect Week activities where she met artists and an English television and radio presenter named Jonathan Ross, among other visitors.
I did rather wonder if she might make it to a third Science Uncovered (alive) but alas, she saw her last sunsets in early 2015. So what did I do with the husk of my fallen friend? Put the kettle on for her, of course. One of the quickest ways to get a desiccated beetle specimen relaxed for mounting is to pop it into warm water (ref. 2.) So after a few minutes of steeping a Beetah tea, I pulled her out of the hot water, wrapped her in moist tissue, and took her to work.
Once at the Museum, I pinned and set Beetah with extra-special care – after all, a Beetah’s work doesn’t finish just because haemolymph stops pumping through her dorsal vessel (or “heart”- but insect circulatory systems are very different to vertebrates’. See ‘Insect Circulation in Short, below). Oh no, I fully expect her to continue public outreach duties long after death- no rest for the dead in entomology! Normally, I would tuck a specimen’s antennae a bit closer to its body to make them less vulnerable to breakage and save them best for taxonomic preservation and study, but Beetah is a common species, already identified and described long ago so setting her for a really attractive dorsal habitus with no limb overlap won out over supreme specimen protection.
Once set out nicely and (re)dried, it was time to label her up and database her. We here at the Museum hope to digitize our entire collection. With 80 million objects, this is no small ask so we’re coming up with snazzy ways to do this as efficiently as possible, but Beetah, being a single and super special specimen, I entered into our digital catalogue individually, manually, myself. Her unique identifier is now and forever 1681080. The data matrix attached to her pin jutting out clearly visible from above can be read by computers and smart phones to quickly access all her collection information. The details of where and when she was collected are now digitally stored along with her species determination, (obituary), and where she’s kept in our cavernous labyrinth of cabinets so she can be easily retrieved for, oh, I don’t know maybe I will make her make an appearance for her third Science Uncovered in September…
P.S. If my son asks any of you where Beetah is… she’s at the Museum. Just leave it at that.
Insect Circulation in Short
One of the more basic zoological divisions in the animal kingdom is that of deuterostomes vs. protostomes. These terms roughly translate to “second mouth” vs. “first mouth”. When the first divot forms in the blob of cells that eventually grows into an animal, it is destined to either become a mouth, or a bottom. Our cell-blob-divot becomes an used-food exit route, so we’re deuterostomes. Insects’ divot becomes a mouth. So right from the start insects couldn’t be much more different to us.
Other equally fundamental differences in development mean that while our nerve chord is in our back, insects’ are in their chests. Our heart is in our chest. Insects’ “hearts” are in their backs. But the location of an insect heart isn’t the only huge difference to our circulatory system. Our blood carries nutrients and oxygen to cells, but insect blood only carries nutrients. Our blood is closed into veins, arteries, and capillaries. Insect blood washes more or less freely around the body cavity. The insect “heart” is basically a tube with muscles and valves that takes in haemolymph from around the midgut of an insect where nutrients from digested food diffuses into the “blood” and then pumps it into the head where it’s released to freely wash over the all-important primary ganglion (brain) and then wishily washily work its way back to the tail end of the insect; feeding cells and picking up waste on its way.
Terms Badly Explained
- Desiccated – Dried up. Because scientists decided one word with 4 syllables is more efficient communication than two one-syllable words.
- Dorsal habitus – The view normal to the lateral plane of the animals’ body. Whatever that means.
- Elytral – Of the elytra, which are the hard forewings of a beetle.
- Haemolymph – Insect blood. It’s not Haemoglobin because it doesn’t bother with oxygen-carrying globulin proteins. There are exceptions- some larvae in oxygen deprived environments have proper haemoglobin but this is a badly explained term, not another blog topic.
- Intraspecific – Within a species. Interspecific would be between species. Like interstates are roads that travel between states. Intrastates would be roads that don’t cross state lines. Like a roundabout in the middle of Kentucky. I’m clearly an American.
- Parasitoid – Like a parasite but much much more dark and disturbing.
- Plural suture – Where the top tough exoskeleton bits meet the bottom exoskeleton bits on the side of an insect’s belly. The side-seam.
- Pronotal – Of the pronotum. Which is the first notum. (Which is the top part of the thorax. The thorax is divided into three sections).
- Spermatheca – a copulatory receptical.
- Substrate – Stuff on the ground. Dirt. Leaves. Gravel. Bark. Sand. And such.
Ref 1. Two of the larvae joined the collection.
Ref 2. This works for any insect that isn’t overly hairy or scaly but is bad for DNA.
Erwin T, Ball G (2011) Badister Clairville, 1806: A new species and new continental record for the nominate subgenus in Amazonian Perú (Coleoptera, Carabidae, Licinini). ZooKeys 147: 399-417. doi: 10.3897/zookeys.147.2117
Gilgado, J. D., & Ortuño, V. M. (2012). Carabus (Oreocarabus) guadarramus La Ferte-Senectere, 1847 (Coleoptera, Carabidae): first instar larva and reflections on its biology and chorology. Animal biodiversity and conservation, 35(1), 13-21.
Gullan, P.J. & Cranston, P.S.. (2000) Insects: An Outline of Entomology, 2nd edition. Blackwell Science, 502
P.S. We moved to WordPress as a new blogging platform for the Museum during 2015. To see the earlier posts in the Beetle blog series, visit our archive.