Learning that ladybirds are vicious predators (adults have more or less that same tastes as their larvae) might go some way to undermine ladybirds’ status as a “cute” insect that escapes the “yuck” reaction so many of their kin seem to evoke. But it’s worth remembering that ladybirds are very useful. Most species specialise in eating plant-sucking insects like aphids and scales, and so can be a boon to gardeners. On a larger scale, predatory ladybirds are often introduced as “biological” control to help keep pest numbers low.
Posts Tagged beetle
A moment of life in the undergrowth captured (leaf beetles playing king of the castle?):
I don’t know exactly what was going on here, though I’ve got my ideas. Whatever I saw, it involved a lot of wild antennae-shaking from the two beetles facing each other and apparently very little interest in proceedings from the base of the “short, blunt beetle-pyramid“.
As I said last week, I’ve just returned from a bit of a summer holiday. I’m not the sort of person who can do absolutely nothing for any length of time, so I tend to find my relaxation in doing things that I wouldn’t have a chance to if I was at home.Like riding a mountain bike. As far as I’m concerned, the best place in Dunedin is the top of Sandymount, an eroded volcanic cone that marks the start of the descent from Highcliff down to Portobello when you ride the Otago peninsular*. I could get all lyrical about the feeling of being away from the rest of the world, or the joy of the moment that you roll from the stiff climb into the fast and flowing descent, but thankfully Brian Tuner has already written a poem about my favourite bike ride:
I push the gear
down a little and the chain
drops onto a small sprocket
and the wheels start to spin
faster, and the air’s
like a quick tongue
in my hair as I descend
swinging in wide
around the hill…
When I spend time at my parent’s house in the Wairarapa I leave my road bike behind and borrow my dad’s old mountain bike to explore some slower, bumpier rides. That’s how I ended up, in the middle of a mid-summer day, struggling my way up a crushed limestone path in a small reserve in Masterton. Bike riding is one of the past times that had to give way when my thesis ate all my spare time, so this really was a struggle. Even riding in the lowest gear I could, I soon gave up on the nice “upright” form that helps a rider spin their way up a hill and instead grovelled my way up, shoulders slumped and head down. And that was a good thing, because with my eyes pointing down I spotted a small creature, seeming to hover just above the ground as it zoomed out across the path, .The creature stopped, turned a few degrees, sprinted down the path a little and stopped again. So I stopped, not, of course, because I needed a break from the hill, but because I’ve read Ted MacRae’s blog long enough to recognise the behaviour playing out in front of me.
If you like bugs and you don’t read Ted’s blog (Beetle’s in the Bush) then you really ought to fix that oversight. He’s a great photographer and an immensely knowledgeable entomologist, but the thing that really springs from Ted’s posts is a love for natural history. Tiger beetles are one of the bits of natural history that Ted loves the most, and its through his photos and posts that I’ve been introduced to these wonderfully rapacious critters. Tiger beetles live almost everywhere on earth. New Zealand plays hosts to a small radiation (12 species, all arising in the last 10 million years, Pons et al. 2011, doi: 10.1016/j.ympev.2011.02.013s) and, although they aren’t particularly rare, I’d never seen one before this day. So I scooted a little closer, and the beetle (raised up from the ground by slender legs, and not actually hovering above it) sprinted a little further. And so it went: scoot. sprint. scoot, sprint, until I got within a metre or so and the beetle added “fly” to its repertoire and disappeared into the long grass.
I was happy just to have at last seen one of our tigers, but I wanted to get a little closer and even see if I could grab a photo of the skittish creature. So that evening I drove out to the reserve and walked along the paths at the top of the hill, hoping to see another beetle zoom into view. A couple of laps of those tracks yielded nothing. If you want to see something interesting the best bet is stop and let the world happen around for you for a little bit, so I stopped. Before long I was watching native (Lasioglossum) bees investigating nesting sites on the ground and then, out of the corner of me eye: Sprint. Stop. Sprint.
Neocicindela tuberculata is the most widespread of our tiger beetles, and an ecological generalist that copes with disturbed habitats as well as beaches, riverbanks and forests. Like tiger beetles everywhere, they are predators that use their bursts of speed to hunt down smaller insects. The harsh light, the beetle’s shininess and my lack of photographic skills didn’t combine all that favourably, but I did get a few headshots that let you get an idea of what happens to a prey item once a tiger beetle has caught it:
I’m not sure, but I think the protuberance you can see in these photos may be an ovipositor – an organ used for laying eggs. These beetles lays their eggs in burrows, and the larvae that develop in them are every bit as fearsome looking as the elders. Since it seemed like this beetle might in the process of keeping this population going, I decided I should let her get on her way while I could be satisfied with a beetle I’d long wanted to see marked off my “life list“. The only problem with being a invertebrate fancier is that makes it another one down, approximately 10 million to go!
* At least it is if you don’t find yourself stuck behind a camper van trundling down the skinny road at 20 kph!
I don’t pretend to be a great photographer, but I do get a lot of pleasure from recording the small creatures I come across. One of the real joys of bug photography is the way even a rank amateur like me can find something that wasn’t obvious at first glance. Take this darkling beetle (tenebrionid) I found the other day. An interesting enough beetle…
It’s Nobel season. Over the next month or so, we’ll hear who has received a telegram summoning them to Stockholm and to fame and fortune (the cash part of the prize is worth about 1.5 million dollars). Of course, the Nobels are a big deal. Prizes are given to recognise people who have fundamentally changed the way we think about the world or the way science works. So it’s nice that in the week before we start thinking about those huge sicentific acheievements we have the Ig Nobel prizes to remind us that most science is small, and sometimes it’s even prettty funny.
The Ig Nobels were set up to honour science that “first makes people laugh, then makes them think”. This year’s winner were announced on Friday and prizes went to researchers who trained a tortoise to yawn on command so they they could find out if yawning was contagious among these animals (it’s not), a Japanese team who developed an alarm clock that wakes you up by spraying a fine mist of wasabi across the room and a team who finally provided an answer to that age-old question – “why do discus throwers get dizzy while hammer throwers don’t?” (here’s that answer). But perhaps the award that’s done the most to make people laugh is the one presented to Darryl Gwynne and David Rentz in recognition of their studies into male Australian beetles that would rather mate with beer bottles than their female counterparts.
|Image © Darryl Gwynne|
Gwyne and Rentz found that they could attract males just by putting beer bottles out, in 30 minutes of observation that managed to lure two of them. Sadly for J. saundersi, this battle with the bottle can have devastating effects. Gwynne observed a beetle being attacked by ants “which were biting at the soft portions of his everted genitalia” and another dead one being eaten by ants.
I have to admit, the idea of a beetle so madly fixated on a beer bottle that it will give its life in the hope of mating with it is so ridiculous as to be funny. So I’m laughing, but is there anything in this research that fulfills the Ig Nobel’s other criterion and makes us think? Well, I’m not sure you and I are so different from a beetle with a pathological sexual attraction to discarded beer bottles.
J. saundersi males had a perfectly sensible approach to finding partners that only broke down when a sudden change in the environment made last generation’s strategy look stupid. Any species can fall into that trap because natural selection, the process that makes organisms fit their environment, has no foresight. All that selection can do is adapt the next generation to the last habitat. Usually that’s fine, but lately habitats have been changing quickly. The rapid technological change of the last few thousand years has left humans in a few evolutionary traps of our own. The most commonly cited example is about food. Until recently, foods rich in fat and sugar were pretty hard to come by. Since these foods are important for regular running of our body, we have evolved brains that reward us when we eat them. Today, our brains no longer match our environment. In most western societies fatty and sugary meals are about 10 minutes drive away and, perhaps not surprisingly, the developed world is dealing with a epidemics of obesity and type 2 diabetes.
I think there is an even more important example of this phenomenon for people that aim to live a skeptical life – our brains developed in a world quite different than the one we live in. The share volume of cognitive biases that psychologists have identified reveal how our intuitions can stray from reality. Not all of those biases arise from a mismatch between our brain and our environment. Brains aren’t truth finding machines, because knowing something is true doesn’t, in and of itself, provide any survival advantage. But some of these mistaken intuitions really do seem to arise from our evolutionary history. Most of the people that have ever lived have done so in bands of about 50 people. Every piece of news they ever learned about the world came through those people, and maybe a few interactions with other groups. Today, I can open a new browser tab and read one of 50 million twitter streams; or watch, read and hear news from almost anywhere on the planet. But I have still have my brain, which mainly evolved to deal with news from about 50 people, so part of me is amazed when I hear someone won the lottery three times, or someone else has given birth to three children in three different years but each at 7:43. Of course, in a world of 6.7 billion people these things have to happen, but, as much as I know that, it’s hard to convince my brain these aren’t amazing events.
I said this fact problem matters for skeptical types, and, indeed, our faulty intuitions can have effects at least as bad as those faced by the amorous beetles that precipitated this post. If you live in a world with 50 contacts, and one of them tells you they got sick after eating a specific sort of food, that’s pretty good evidence that you should avoid that food. If you live in a world with billions of potential contacts, and one of them tells you that someone, somewhere got sick after receiving a vaccination or got better after taking a homeopathic remedy that’s not evidence for anything. Just like the triple lotto winners, in a world where millions of doses of vaccine given out, someone will get sick after a vaccine whether it causes an illness or not. Thankfully, we’ve developed methods that help us, as much as possible, to remove our intuitions from the way we handle evidence. Together, we call those methods science and it’s crucial that those methods are the heart of the way our societies develop if we are going to avoid our own evolutionary traps
So, by all means laugh at J. saundersiand his futile, fatal attempts to impregnate a glass bottle, but do try an be aware that similar traps are lurking in our own brains.
*For people outside Australiasia, a stubby is a short brown 330 mL bottle which usually contains the caramel fizz that gets called “ale” or “draught” beer down here, but is, in fact, a lager.
Thanks to Ted, the blogo-sphere’s foremost beetle taxonomist for pointing out this species is not called J. saundersi, as it has been shown to be distinct from J. bakewilli the name this population bore when the paper was written
Issac Asimov provided one of my favourite quotes about science
The most exciting phrase to hear in science, the one that heralds new discoveries, is not ‘Eureka!’ (I found it!) but ‘That’s funny…
Scientific questions are almost never solved in eureka moments. Answers take time, planning, analysis and, finally, results from multiple studies made available for the scientific community to scrutinize. But there plenty of exciting moments in science, and there is nothing quite like the feeling of noticing something that doesn’t quite fit with the way you think the world works. From there you can start spinning off theories that might explain the anomaly, and most excitingly, think how you might test those ideas against reality.
Something a little bit similar goes on in the life of a bug nerd. There are lots of creatures I’d love to see and never have. I’ve never seen a tardigrade, or a mantidfly [you really want to click that link, they're amazing] and reading Ted’s blog means I’m forever looking out for one of our native tiger beetles. It’s definitely a thrill seeing finally seeing some creature that you’re read about and seen photos of, but it’s at least as exciting to see something you didn’t even know existed. For a bug nerd, “What the …” is just as exciting a phrase as “A’huh”, and that’s exactly what I said when I turned some tree bark and found this spiky little guy:
Just as “That’s funny …” is a trigger to hypothesising and mentally developing a research proposal, “What the …” is a precursor to reading searching, viewing and poking about in the hope of placing the strange creature into what we know about life. I have to admit I haven’t got very far in this particular example. The thickest of those tufts mark the back end of the animal, and I’m pretty confident it’s a beetle larva (you can make out two of the three legs on the near side of the body is this photo). Beyond that I’m a bit stuck, there are plenty of weevils with larvae that live under bark, but this doesn’t look like any I’ve been able to find. Similarly, quite a few beetles in the family Dermestidae (called ‘skin beetles’ since some species are scavengers of animal corpses and some even specialise in eating hide) have spikey looking larvae like this one, but I can’t find any helpful references for these beetles in New Zealand and don’t know if there is a give away as to whether this animal fits in that family. If anyone knows what this is, or might be, I’d love to learn!
The photos I share here are really not representative sample of the bugs I come across in my travels. For me to get photos of a bug I need to get pretty close to it, and that means i can’t get nice pictures of creatures that are skittish or particularly fast moving. For instance, there’s a longhorn beetle (Cerambycidae) species I find quite often in Dunedin but have never taken a nice photo of, because every time I line one up the subject runs out of frame or out of focus.
Even though I’ve never taken a good photo of this beetle, I do have one that displays it’s most unusual feature. It has two ridges growing out of it’s back:
I can’t imagine what, if any, purpose those protuberances serve, but i quite like them. Their spikiness, and their shape makes me think of tiny little circular saw blades sticking out of a saw bench.
Last week I told you all that I had a great idea for a Sunday Spinelessness post, but not enough time write it. So, of course, this week I’ve managed my time in such a way… that there’s still no way I’m going to get to write that idea up.
I’ll leave that idea for another day, and, instead take inspiration from one of Alex Wild’s recent posts at Myrmecos. The bug-blogo-sphere is filled with wonderful photographers, producing absolutely stunning portraits of the little creatures that run our world. When I go out fossicking for bugs, it’s images like Alex’s ants and Ted’s beetles that I have in mind. That mindset inevitiably leads to dissapointment, since I’m restricted to a point an shoot camera. As much as I love my camera, it’s never going to challenge dSLRs for image quality and its lens can’t produce the sort of magnification a really good macro lens can. But, Alex points out, I shouldn’t be disappointed that my camera can’t do something it’s not designed for, instead, I should take advantage of some of the things digicams really are good at. In partcular, the small lenses used in these cameras create a wide depth of focus, which can capture not just a bug, but a little of the the way the world looks form a bug’s point of view. With this new idea in mind I went out today and… well, completely failed to get anything interesting. It was a grey sort of a morning here in Dunedin there wasn’t much life out at about. Instead, here are a few older images that gel with Alex’s tips:
First, a soldier beetle looking for food in masterwort flowers in the UBC Botanical Gardens in Vancouver. I tried, and failed, to get a close up of these beetle’s face; but did get this one:
Flowers seem to be the over-arching theme in thse photos. A bumblebee visiting a dahlia (I probably should have thought a bit harder about the background here…):
I’ve taken a few decent photos of bumblebees, but I’ve never taken a good one of a honeybee. Or at least, I’ve never taken a good photo of a sinlge honey bee, I quite like this one with hundreds of bees flying in and out of their hives.
And finally, back to the dahlia for my favourite of these photos. A tiny fly, far too small for my camera to capture in any great detail, but looking pretty good in this setting:
edit: I forgot to include a link to The Geek in Question, who followed up Alex’s article with some more great tips
Time for another tropical beetle from Vanuatu, and what could be more charming than a ladybird*?
Or its absurdy spikey larvae?
This ladybird is probably a bit larger, a bit rounder and a bit oranger than the ones you are used to seeing in your garden. The more familiar ladybirds are more that just a pretty set of elytra, they’re a force for good. Both the larvae and the adults of most of the familiar red and black ladybirds eat aphids, so having a few around in your garden saves on insecticide:
The big orange ladybird in that first photo is not nearly so helpful. It’s Henosepilachna vigintioctopunctata**, commonly known as the 28 spotted ladybird or the hadda beetle. The hadda beetle is a major agricultural best, because both the adult and larval stages are herbivorous and have a patricular liking plants of the family Solanaceae. That means potatoes, tomatoes, eggplants and (worst of all?) chilies can have their leaves skeletonised by beetles, and a beetle infestation can reduce a year’s crop by up to 25% if not controlled.
You might note that this is the third post I’ve written about invertebrates from Vanuatu, and it’s the third time I’ve written about an introduced pest. That’s not by chance. Islands are hugely interesting for evolutionary biologists, but human introductions have seriously changed island ecosystems.
Take another look at that chewed-over leaf. Now imagine that each of those small white sections to the left of the photograph is a brand new island in a green ocean. In almost no time at all, winds would carry seeds to our little archipelago and life would start to claim the bare rocks. But we don’t know which plants would make it. Dispersal and colonisation are random events, each island would collect its own subset of the seeds drifting past , and so start to develop its own flora. Once those plants have taken hold, the rain of wayward and drifting insects (and even snails) that fall everywhere on earth would have a chance to establish themselves. Again, the isolation of our islands means different species will fall on each one, and different ecological relationships will start to form. Our islands might survive for 20 million years before they’re reclaimed by the sea, and in that time the unique beginnings of each island’s ecosystem will mean a different evolutionary history will play out. In this way islands are evolutionary experiments, and island ecosystems have given risr to some of evolution’s weirdest creations – isolation from the mainland has let iguanas become marine animals, finches become vampires and pigeons give up on flying.
But islands are no longer isolated from the rest of the world. The hadda beetle is probably native to Russia and, without humans moving plants around, would never have had a chance of making it to a Pacific islands. Now it lives in almost all the way across the tropical Pacific (here’s a terrible photo of one I took in Rarotonga, 3000km away from Vanuatu):
In fact, there is an entire “tramp” assemblage including, but hardly limited to, big-headed ants, mynas, land snails, centipedes, paper wasps and mile-a-minute weed that can be found almost everywhere you find people in the tropical Pacific. These Pacific-wide introductions have pushed out native species, and together they have replaced some of evolutions most exuberant expressions with a bland mono-culture. The problem is not quite as bad as it might seem. The tramp species are mainly moved about by commerce, so many of the introduced species are associated with agriculture or at least lowland environments. In most islands, as you climb higher you find a more ‘native’ flora and fauna (for instance, all the partulid species left in the Society Islands are restricted to mountain tops).
By the way, the hadda beetle’s bid for world domination continues: last year it was recorded in New Zealand for the first time. It’s known to have set up shop in Auckland, but if you find hadda beetles somewhere else MAF might want to know about the invasion’s spread.
*That’s “ladybug” in American English, coccinellid or “lady beetle” among scientists and “ngoikura” in MÄori
** That name might seem like a mouthful, but the species epithet at least makes sense, viginti-octo-punctatameans “twenty-eight-spotted”. Most ladybird species names follow this rule
As promised, it’s time to add a few tropical invertebrates to the mix of more temperate bugs I usually talk about here. Let’s start by redressing a bit of an imbalance in these Sunday Spinelessness posts. Up until now I’ve only written two posts about beetles, which something of an under-representation since about a quarter of all described species are beetles. I see plenty of beetles around our garden and in my travels around Dunedin, but few of them are large enough, or sufficiently cooperative, for me to get decent photographs. I had no such problem in Vanuatu.
For a start, there was the daily invasion of giant scarab beetles. Around 6 o’clock each morning a wave of massive bumbling beetles would arrive at one of the
coconut betel nut palms surrounding the house at which we were staying. If you stood under the tree and looked up all you could see was the yellow-bodied beetles moving about and a rain of white stamens falling down from the flowers they were busy destroying. The beetles that came late for the feast set themselves up in the shrubs underneath the palm to scavenge what they could, and were quite happy to pose for photographs:
A few of the latecomers even got a whole flower for their patience:
I can’t identify these beetles to species. Their stout bodies and legs and their particular ‘clubbed’ antennae mark them out as scarab beetles (family Scarabaeidae). That’s the same group as most well known of our native beetles the excitingly named “brown beetle” more famous for its larvae which we call grass grubs. The only extra bit of information I have on them is from this post summarising a discussion on a mailing list that deals with emerging crop pests. It seems they’re a known problem in Vanuatu, and taxonomists have at least got as far as placing them in the subfamily Cetoniinae, which are sometimes called “flower chafers”. From the point of view of a snail geneticist (and not a beetle taxonomist) they actually look very similar to an Australian Cetoniine species, Eupoecila australasiae.
Had I known they were such a problem for commerical coconut growers I might have spent less time rescuing these beetles from the swimming pool. Their attraction to the bright-blue sheet of water proved lethal more than a few times, but it did make for some great photo opportunities: