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Sunday Spinelessness – Cannibalism in the garden David Winter Feb 03

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The most common jumping spider in our garden, Trite auricoma, with the remains of it most recent meal… a smaller T. auricoma:


Cannibalism,  animals eating members of their own species, is a pretty common and widespread behavior. Species in almost every phylum have been shown to occasionally (or frequently) eat members of their own species. Even herbivores like monarch butterfly caterpillars will eat any monarch eggs they encounter.

In spiders, the most well-studied form of cannibalism relates to mating. In a very few species male spiders will offer themselves as a meal to their mate. In so doing, males make sure their offspring get the best start in life, by providing their mother with a nutrition meal. They are often also posthumously rewarded by female, who reject other suitors and ensure the sacrificial male’s legacy. The best example of this behaviour comes from the Australian red back spider (Latrodectus hasseltii). In this species males actually pirouette their way into their mate’s fangs, and females take up the offer about 65% of the time. New Zealand’s endemic red back relative, the katipo, does not exhibit this behavior (nor does the North American black widow, despite the name).

Such sexual cannibalism isn’t known from jumping spiders (although females will certainly eat unwary males), and a wider (and earlier) shot lets you see that this was a case of a mature spider taking a younger one (males and females are about equally sized in Tauricoma).



Sunday Spinelessness – Native bees again David Winter Jan 27

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Last year, at about this time, I wrote a little about our native bees. Though I’m glad to have done my little bit to promote the existence of these all too anonymous members of our natural heritage  I’ve always felt a little embarrassed by the photos in that post. As I admitted at the time the photos are staged. Photographing our twitchy little bees is hard – apart from being small, they zip about from flower to flower much more quickly than I can line up, let alone focus, shots.

So, to illustrate the original post I used half-drowned bees, scooped out from a swimming pool. The time it took the bees to dry out gave me a chance to take the photos, but I set them up on exactly the type of flower they’d never visit in the wild. So, not only did I cheat, but the photos I took actively misled about the true nature of bees!

So, here are some much worse photographs of native bees that do a much better job of representing their lifestyles. First off, a bee perched on a favourite flower, a hebe,  and deciding on its next move:

 

and another collecting pollen from the same plant:
These hebes, and a few parsley plants left to go to flower, make my parent’s house in the Wairarapa a mecca for native bees. They certainly make their mark around the garden, if you don’t notice them drowned in the pool or visiting flowers you can see their nests in the soil:

Sunday Spineless – On the Wing David Winter Jan 13

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Just a photo today, but a pretty awesome one I reckon. An inbound bumble bee from my parents’ garden in the Wairarapa:

(~50 out of focus shots from same session not shown!)

Sunday Spinelessness – A Clearwing moth David Winter Dec 09

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At last, Dunedin has managed to arrange a proper summer day for a weekend.

The extra heat and sun saw plenty of bugs out and about, and I spotted plenty of familiar critters (native bees,  cicadas, drone flies and magpie moths) for this first time this year.  The real find of the weekend though, was something entirely new to me:
 

You might be a little surprised to learn that you are looking at a moth.

I’m helping design an undergraduate lab on systematics and taxonomy at the moment.  Since the new lab is about insects I’ve suddenly become very aware of the traits that distinguish various insect groups.  Moths, along with butterflies, make up the order Lepidoptera. You can see a few lepitoperan characters in the above photo: a mouth designed for siphoning nectar from flowers and a body covered in fine scales.

“Lepitoptera” actually mans “scaley wing”, and, indeed most butterflies and moths have scales on their wings. This species, though, has got rid of most of it’s wing scales (there are plenty of scales on the trialing edge though):

Synanthedon tipuliformis * is member of the “clear wing” moth family Sesiidae. Although I think this one is pretty neat, the family contains some striking species, the most interesting of which are wasp-mimics
Bembecia ichneumoniformis photographed by Lamois and licensed CC3.0



Yes, that’s a moth! Sesis apiformis from Flickr user Oldbilluk. Licensed CC2.0




*The species name means, I guess, “looks like a crane fly“… don’t see it myself

Sunday Spinelessness – Bark Lice David Winter Dec 02

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I should have known that the little challenge I put up last week wouldn’t so much as wrinkle the brow of the bug-blogo-sphere’s best. The Atavism‘s two homes means there were two winners. Ted MacRae of Beetles in the Bush chimed in at he blogspot version, correctly identifying the insect as a “bark louse” or psocopteran, and recognizing those stubby white protrusion as yet-to-be expanded wings . Morgan Jackson of Biodiversity in Focus did the same at SciBlogs.

Thanks too to Deborah from Bee of a Certain Age, who hazarded a guess that those white protrusions might be eggs. Certainly a more reasonable guess that my own first thoughts at seeing these bugs crawling over the the Big Tree* in our garden. The plump abdomens and long antennae made me think of the large (but certainly not GIANTspringtails. Ripping up a couple of pieces of bark revealed a whole colony of these odd-looking bugs, and evidence for just how wrong I was. 

The adults have wings, which they hold tent-like over their bodies. Insects are the only invertebrates with wings, so, since spring tails aren’t insects, my first guess was horribly inaccurate (glossing over about 400 million years of evolutionary divergence).

As Ted and Morgan worked out, these are “bark lice”, members of the order Psocoptera. Although they are related to the “true lice” (Order Phthiraptera), psocopterans are not parasites. Rather, they wander around their trees eating algae, fungi and whatever detritus might be clinging to the bark. The only species that could be considered pests are the “book lice” – small flightless psocopterans that sometimes turn up in old books where they eat the paste that binds pages together. (I have it on good authority that book lice can also destroy botanical collections, so certainly a pest)

A couple of weeks ago I gave Veronika Meduna a tour of our garden and its bugs, and I gather you can hear the result on Radio New Zealand’s Our Changing World next week. While I was catching my breath between talking about the mating habits of spiders, and how our native slugs are much more sluggish then their introduced counterparts she asked the obvious question – “why?”. Why do I care so much about odd little creatures like bark lice and slugs and spiders? I’m not sure I managed a coherent answer at the time, but I can tell you now, spineless creatures need evangelists because most people have a very skewed view about the way biology works. If your vision of biodiversity is limited to pandas and dolphins and lions and tigers then you are missing out on millions of other ways to be alive.

Take bark lice as an example. I’ll admit that I’d never given these creatures a moments thought  before running into them last week. But, in researching this post I found out there are more than four thousand psocopteran species. That is to say, there are almost as many bark lice species as there are mammals – all the lions, tigers, bears, dolphins, whales, marsupials, rodents and bats in the world add up to about 5 400. That matters because species are the fundamental units of biological diversity. Each species represents a distinct evolutionary lineage – free to take up different ecological niches, develop new morphological features or occupy a different geographic range.

To try an illustrate how diverse these unassuming little critters really are, I’ve put together a “treemap“. In the plot below, each of the stained-glass window panels represents the number of species in one psocopteran genus, nested within a family (the heavier lines, with labels ending in -DAE) which in turn is nested within a suborder (the very heaviest lines, labeled -MORPHA). These higher taxonomic ranks are not fundamental units in the way species are. Even so, species placed within a taxonomic group share evolutionary history, and are united by particular morphological characters which they share.  It turns out there are quite a few ways to be a bark louse:

And that’s just bark lice!

For me, this chart is the best answer to “why?”. How can you know you share the world with all this extraordinary diversity and not want to want to spend your time working out how it got here?



*This is not a botany blog… I really have no idea what the tree is

Sunday Spinelessness – An ID challenge David Winter Nov 25

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OK, here’s a chance for the bug nerds to show off. A photo of a strange-looking beast I recently ran into:

 

The challenge to readers is to answer the two questions that went through my head when I first uncovered the creature (1) What the hell is that? (2) What’s going with those opaque white projections?
Unlike others, I can’t often you anything cool as a prize for being right, but surely an electronic record to your entomological know-how will be enough?

Sunday Spinelessness – Shocked from sloth by a beautiful spider David Winter Nov 18

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Regular readers will know that I’ve been pretty slack in posting here in recent weeks. Just the same old boring reason – lots of “real” work to get done and, as much as I enjoy it, blogging necessarily floats to the bottom of TODO lists.

But I was shocked from my sloth this afternoon when I passed that accursed agapanthus and saw a spider I really had to share with the world:

It’s an orb-weaving (araneid) spider, a relative of the familiar garden spiders like the very common Eriophora pustulosa that spin orb-shaped webs and catch unlucky flying insects. I can’t be sure on the identification of this one, but I reckon (with some support from twitter’s resided spider experts, [1], [2]) its a species a species of Novaranea. According to Ray and Lyn Foster’s  Big Spider Book New Zealand Novaranea species are most commonly encountered in in grasslands and tussocks, so perhaps this one blew in from the tall grass that covers some the abandoned gardens in our block.

However it made it our garden, I’m very happy to have encountered a such a neat looking spider, and even done a half-decent job capturing some of its beauty:

Sunday Spinelessness – Nothing to see here David Winter Jun 03

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I’m off to the Transit of Venus Forum next week. I’m looking forward to meeting all sorts of clever and interesting people (and escaping the coming snow), but travelling and conferring won’t leave much time for a few projects I really need to work on. So, today’s blog post is going to have to be squeezed down to its smallest possible form (a queen ant that dropped in to read an early draft of my thesis last spring):

Sunday Spinelessness – Even their eggs are spikey David Winter May 27

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I really like the leaf vein slugs (Athoracophoridae) that live in our garden and  have featured here in the past. Here’s the latest one to pass under my camera:

As much as I like them, I have to admit these guys are actually one of the more boring leaf vein slug species in New Zealand. Some of their relatives are much larger or more colourful and quite a few of them sport large wort-like growths (technically called papillae) that pattern their bodies in various ways. Te Ara and Soil Bugs both have galleries that let you get an idea of their diversity.

A couple of weeks ago I made a little discovery. Some of these slugs also have eggs that are covered in papillae

Not the greatest photo I’ll admit. But it’s hard work taking photographs in the dense New Zealand bush at the best of times, and I found these eggs in the low-growing cloud forest that covers the Leith Saddle on Mt Cargill. These are certainly slug eggs, so  I did a bit of snooping among Astelia and ferns and other likely looking roosts for these nocturnal animals. I couldn’t find any parents-in-waiting, but the ferns were utterly covered in what people that follow mammals might call “sign”, so clearly there’s a big population in the area. 

Sunday Spinelessness – What’s brown and sticky? David Winter Apr 22

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Yup, I’m continuing with last week’s theme of terrible jokes. Of course you know the punchline for this one, what’s brown and sticky? A stick:

Both the objects in that photograph are brown and fairly sticky, but the one in the background is a bit more interesting.

That’s not a stick – it’s an insect doing a very convincing impersonation of a stick. Stick insects ( ‘walking sticks’ in North American, Phasmatodea everywhere in the world) are among the most impressive mimics in the biological world. As you can see, their bodies mirror the tiniest details of the plants they live on – right down to having stems and buds. The stickyness of stick insects goes deeper than their remarkable appearence – they also act like sticks. The rigid pose you see above is the result of my disturbing this one while trying to take a photo. The insect was so dedicated to its role I could easily pick it up and place it on its leaf while it maintained its spread-eagle pose.

A few minutes later it was on the move:

I don’t know what species we are looking at here. There are about 20 named species in New Zealand, though that is probably an underestimate of the true diversity. There seems to be lots of interesting biology going on among those species – species with sexual and asexual populations, a genus that arose by hybridisaton and one genus known only from two specimens. It’s possible this one is Niveaphasma annulata - a species that has patchy distribution across much of the southern half of the South Island and is pretty common in and around Dunedin. What ever the species name, here’s the beast making a bid for freedom from the faked-up leaf litter I put together for this little photo-shoot:

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