Subterranean vs standard pitfalls: Run 1


Having learned some valuable lessons from the pilot run (see last post); and encouraged by initial data analysis showing potential differences between both trap type, and plot; I decided to start the first run of trapping with subterranean and standard pitfalls at Brooms barn.


Unfortunately the grass was harvested just before my run, damaging and obscuring the traps in these plots; so for this first run we set out in just wheat and barley. Still, this comprised 14 of the 20 plots I will be using from the rotation experiment (see picture) and 42 traps of each type!

The weather conditions were still rather unfortunate, and combined with my long pole markers not being delivered (finding traps still time consuming), my gingerness under extreme high temperatures forced us to split the setting and collecting into two offset trap occasions.

The drought did provoke some interesting distinction in the trap types however: the standard pitfalls nearly all dried out, despite my entomologically expert assistant advocating extra water in in the trap fluid. This caused the traps to be filled with live specimens: particularly carrion beetles who were attracted to the rather ripe odours; an unanticipated pleasure for me, since they are so gorgeous!

This is a great comparison to the subterraneans that did not dry out, and had a pretty equal volume of coleopteran catch, including smaller and undamaged beetles, yet more general invertebrate catch (since live carabids predated). Whilst this run is obviously biased: I cannot know to what extent the subterranean nature of the trap affects the catch composition, against in-trap predation; it suggests a clear advantage of subterranean traps in drought conditions.

The time since the traps were collected on the 26th and 30th of July has been spent entirely counting beetles. So many beetles. Around 3,800 carabids. Identification has been a steep learning process, even given my past experience. I haven’t yet identified all the tiny ones, but I wanted initial data to present at an upcoming conference, hence the full on rush. A couple of tips:

  • 1) Don’t rely on just one guide. Alex Greenslade of the Rothamsted insect survey kindly pointed me to Duff, which I found much more accessible than Luff, and some great online guides including mike’s insect keys ( I found going between these sources was much easier and cleared up subjectiveness in singular interpretation.
  • 2) Ask others. If you’ve been banging your head against a dichotomous key for hours, it’s easy to lose the plot. Chris Shortall and Dion Garrett, my entomological PhD colleagues, have been most benevolent in this regard.
  • 3) Utilise past data/ collections. Consulting species records for Brooms barn gave me a springboard on a couple of species, and Alice Mauchline, my Reading uni mentor kindly lent me her beautiful reference collection of carabids, caught in agri-environments.

Though I have just started data analysis, I am already seeing some stark differences in trap type (incorporating those weather biases of course) and crop. I have also found some larvae, despite an overall dearth of soil moving invertebrates!

With so many traps I hope to pick apart some nice nuances, especially since the experimental plots comprise till and no till treatments… The next run should elucidate and further the distinctions, especially with inclusion of soil core samples and grass plots.

But if you want to know more you’ll have to wait awhile; or come and chat to me at Ento 18!




Pitfall pitfalls


I finally got to set my pilot pitfalls at Brooms barn the other week (see last post update with happy cartwheel), and, rather typically of any fieldwork, things didn’t go quite as expected…

Problem 1- Where did I put them again?


I had decided to run 3 of each pitfalls (subterranean and standard) in one plot of each crop type. However, the first plot on the list was grass. As you can see it got a bit tired and decided to have a lie down. All over my traps.

They do have short markers (see this in barley) but we couldn’t find a single one.


Lesson 1 = Bigger markers next time. We decided to just do the pilot on two plots: Barley and wheat.


Problem 2- Weather conditions


Always a kicker with fieldwork. On this occasion it affected the settling of the traps, and the catch. The settling as you can see is not great, the soil should set in close to the wire, and inverts should be able to move naturally through the soil. With it being so dry, rain and soil biota hadn’t acted to settle in the traps well and some subterraneans had carabids trapped at the bottom in the hard soil. Poor guys, we couldn’t even get them out!

My objective is to test pitfall trapping efficacy on soil active carabids (adult and larvae, see past posts), so it is a worry that i won’t get much in these conditions. Indeed when we went out to collect the traps last week, the catch was so low (few arachnids, slugs and adult carabids) that we decided to leave them another week.

Lesson 2 = Extra soil filling in before first set. Soil moisture measuring to measure dryness as a factor on activity density.

Problem 3- Unintentional catch



Anyone familiar with pitfall trapping will have a tale of mice in traps, but this shouldn’t have been a problem with the subterraneans, they have a lid so that surface active organisms don’t fall in. However this charismatic fellow was sheltering under the hat, at the side of the trap. Then when my lovely assistant lifted the lid, the poor guy was so shocked he jumped into the trap! We had to go away, leaving a ladder of wheat stems, and come back to set that trap last.


The standard pitfalls were unset with lids on the cups. However, one lid was damaged, and we discovered a rather frantic community of starving carabids, with remains of the less ferocious denizens unlucky enough to fall in! This did actually present an opportunity for these unfortunate souls to be the stars of Rothamsted’s festival of ideas; gracing the ECN stand, and my flash talk. They are now happily living on a diet of ham, turkey, and banana in my office.

Lesson 3- Wire down the ST hats. Take care on setup, and check traps regularly.


For all the hiccups, it was great to get out there again, and I’m so excited to start getting some data of my own to work with… Watch this space 🙂


Subterranean pitfall update 2

A quick recap due to it having been awhile since my posts:


Subterranean pitfalls (STP) work on the same premise as standard pitfalls; catching invertebrates falling into a pot; except these are set underground, catching soil active invertebrates. This is incedibly useful as I want to study the distribution of carabid larvae relative to more surface active adults.




The initial test STPs proved very successful, supplying me with the charismatic but star crossed Tony (R.I.P 😦 ), and plenty of shiny specimens!

So given their success I decided to make 60 of them! When I say I, I mean it in the broadest terms, these were created with the kind help of my fabulous supervisors Alice and Jon, and the fantastic skills of Nick in Facilities at Rothamsted!




These are to be run in a field experiment at Brooms barn, one of Rothamsted’s farm sites. I have installed them in the new ‘long term experiment’ there, which consists a mosaic of adjacent plots of differing crop, input and cultivations. This will give me both a choice experiment around the plots I have chosen; and a methods test of pitfalls against STPs, and also soil cores.

Again when I say ‘I’ I mean it in the broadest terms! It took two day efforts to install 60 STPs and 60 pitfalls; with the incredibly generous help of Alice, Jon, Helen, Dion, Jonah, Timo, and Hannah. Thanks team 🙂



Well. That was a month ago, meaning (due to soil settling) it’s finally time to go and set them up for a pilot run! YayyyyIMG_0929.JPG

Working hard is hard work


Drudgery can be fatal in academia and it’s time we started talking about it.

I haven’t updated my blog in quite a while now, because I haven’t had anything “interesting” to report.

I realised today this is a flaw.

It is coming to light of late, that research is heavily biased by sexy science; dictating the communication, prevalence, funding, and ultimately, direction of all research. Much of the research that could be vital to the well-being of humans and our planet involves “boring” and “uncharismatic” species, and/or old, large, and complex datasets.

It takes a special brand of enthusiasm to persevere under such conditions. So it is no wonder that mental health is such a big issue in academia. Impostor syndrome is approaching a cliché, but it is far from a joke. As pragmatic and resolute as I am, I find myself falling victim to feeling inadequate because I’m not churning out some undefined measure of progress on my project.


I externalise with my notes in Genstat…


But over the last weeks I’ve been working really hard! Working through data and the vagaries of statistical packages; endlessly corresponding over admin and arrangements; designing and checking the fieldwork program; back checking and keeping up with literature…. See, it doesn’t make fascinating reading; but I’m in the privileged position of having some measure of self-confidence, and the support of a great team of colleagues and friends.

 Suppose I was beavering away in a less salubrious environment, I might give up altogether! So I think we need to talk about our drudgery. Remind each other that there is a mountain of it for each success, and we are all going to feel like we’re tunnelling at some points. It doesn’t mean we’re not doing it right.

 By the way, my project’s going great 😉

An entomological first foray into oil pastels

You may have noticed from my last Tony post that I am somewhat of an artist. I am not good or prolific enough to make a living at it however, and nowadays only draw as gifts for other people. Strangely I work best this way, I have found that art under duress lacks something of a soul, at least for me. Anyway, I had occasion to express gratitude to an entomological friend, and what better way to do so than through the medium of beetles?

This was the perfect chance to try out my new oil pastels. I picked them up in a charity shop by chance, thinking they were normal pastels. I find pastels a tremendously quick and easy medium, however they would not be suited to express a shiny carapace. Usually I would turn to my art pencils, these will deliver a deep, precise shiny result; but only with a lot of layering. Oils or acrylics of course would be ideal, but mine are in Derbyshire, and neither is a quick medium.

Knowing the crayon shape, I set up a black starting shape to ensure detail clarity. Like pastels, fine lines are out. I used a fine pen, this also showed through nicely to give the impression of the texture and shine of the carapace.
Oil pastels feel really strange after normal pastels, they behave similarly and differently. You can layer and blend a bit, but with care: too heavy and it clumps. Luckily unlike pastels you can actually scrape off the colour with a sharp tool and re-blend. They also erase with a rubber nicely. This means you can get some great crisp lines to edge, but sadly not in isolation.

The colour intensity means forward planning is crucial. The black and white interplay was difficult, smudging each together takes practise to get right. I had to scrape and go over a few times. But the sheer deepness of that black really impressed me. However, I am not entirely happy with the whiteness of the shine I achieved on the elytra, I couldn’t scrape back to the background entirely on the tan colour. So something to remember for next time.

Overall I am delighted with the result, I think it really suits the subject, and will definitely use oil pastels for entomological art again!

On wild animal rescue and conservation values…


I was talking to my entomological friend and colleague, Dion, the other day. It came up that far from reflecting our love of invertebrates; our respective PhD projects exploited and sought to control them, for anthropocentric gains. He kindly countered that my affectionate care of Tony demonstrated my laudable inclinations! (Besides which, I was joking: we both know that conservation of invertebrates in farmland, and more widely, is tied to human wellbeing) I told him it remains to be seen if I can actually keep him alive; I don’t have a terribly good track record…

This got me to thinking about my various wildlife rescue attempts. And there are rather a lot. I think I was about nine when I first brought a juvenile bird home. In all honesty, I shouldn’t have taken her: as all wildlife charities advise, parent birds are usually nearby. I knew this, but at nine lacked the moral fortitude to resist having a wild pet.

“Dusty” was actually a success. A collared dove, she was actually easy to rear; and her descendants still grace the oak tree in my old garden every year. But that was followed by many failures. Long experience (of waking up early to feed them every 20 mins, only for them to die) has taught me that songbird chicks are not worth the effort. My next success was a high note in my life though.

“Rune” was a carrion crow, she came to me half starved, from a plundered nest. As a near fledgling she was easy to raise, I hand fed her cubes of cat meat until she could take care of herself. Rune got me through a very difficult time in my life. Caring for her took me out of my own navel gazing depression at the age of 16, and helped me out into the world. I would take her for walks, but far from perching on my shoulder looking all cool like in ‘The Crow’, she bobbed along sat atop my head, and shat all down my Korn hoodie…

It didn’t end particularly well for me though. Someone let Rune out of her run (after reporting me to the RSPCA who approved her care BTW) and I never knew what happened to her. It still brings tears to my eyes 15 years later. But I like to think she’s out there, somewhere. Since that I’ve taken in a few injured corvids: 2 car hit rooks, a cat savaged magpie; but all died from complications soon after.


A notable case was an injured Buzzard. I found him in a client’s garden (I was a gardener) eating gooseberries! It was an honour to observe such a stately bird at close quarters, as I held and inspected him. But upon taking him to Brinsley animal rescue (a damned worthy charity) though, I decided, and was advised it was best to put him down. He had been hit somehow, was blind in one eye, his leg was broken but healing, and being severely underweight it seemed this happened some time ago. Explaining his eating gooseberries in desperation. He could survive. But as a wild bird of prey, he’d never be happy. A crow’s intellect could help it adapt, but a buzzard who recalls hunting, yet can’t hunt, is not going to thrive.

I realised though, in the reverie following my chat with Dion; that all of these have not been worthless. Each time I have learned about the species, got to really understand them up close; and appreciate them as no cold experimental conditions could ever hope to. Our human passion for conservation should not be separate to science I feel. Just as conservation should not be separate to productive farming. Humans dominate the world, for better or worse; but we are still just a cog in an ecological system. Appreciation is the first step to integration.

I lack the resources to care for any large animals now, but I shall still carry on. Caring for wild invertebrates is just as interesting, especially if you can observe their different life stages. Fingers crossed I can see Tony grow into a beautiful beetle!

Brinsley animal rescue takes in many cases and cares for them much better then I ever did. If I’ve tugged your heartstrings, support them:


Never work with children, animals, or immature beetles…

Having had difficulty sourcing carabid species images, especially for larvae; I decided Tony presented a great opportunity as a model. Images could then be used for ID, reference, diagrams, extension, and promotion. The latter is very important. From the start it has surprised and delighted me how people have engaged with “Tony”, in the office and online! I have had lots of questions, so it has furthered understanding and appreciation of carabids and beetles more widely. Also I have got some new beetley contacts too.

So how does one go about photography of such a tiny and rapid creature? Well it’s a lot easier if you have access to the fantastic Visual Comms Unit at Rothamsted! Graham Shepard is a superb photographer; but he has had little experience of such a tricky entomological subject: his usual crop pests are much more willing to pose. However he rose to the challenge, we had a great time and got a few really good shots.

I brought along some moss and soil, and set up a small diorama of beetle habitat. In practice this was great for Tony, but not so much for Graham. Subterranean larvae naturally burrow away from the light as soon as they can, so I was fishing Tony back onto the moss, then Graham had a few seconds to snap shots before he found a way back down… Also Tony was quite upset at being forced to perform, flicking his body to escape, and actually biting in retaliation. Those tiny sickle shaped jaws are no joke. He literally hung off my finger at one point! (Don’t be afraid of larvae now though folks, he’s too small to draw blood and I couldn’t feel it)

Next we tried him on plain backgrounds, this was easier as Graham was able to track him for longer over the paper as Tony ran; before I flicked him back to the middle with a paintbrush. Still, it takes time to focus in properly; and Graham exhibited remarkable skill and patience in capturing a few fantastically sharp shots from this: you can see every hair, which is very important for larvae ID.

Tony the Pterostichus
Image credit: the wonderful Rothamsted VCU 🙂

Anthropomorphising aside, it really has been a great learning experience. Seeing how a larvae moves through its environment, evades capture, and the behaviours it uses in defence; feeds into my understanding of their autecology. I was particularly surprised at how well a predominantly subterranean instar could move on the surface. And I actually really didn’t anticipate how feisty they are!