Friday natural history: death in the garden

July 8, 2011 • 5:20 am

Reader Ray Perrins, from England, sent me a photo he took in his garden.  It shows the fascinating natural history—and natural drama—that can be found even in your own back yard.  I should add that what Ray didn’t mention, but is very obvious in the photo, is that this hoverfly is almost certainly a Batesian mimic of a bee. (“Batesian mimicry” is the phenomenon in which an edible, tasty species evolves to resemble a dangerous or distasteful species that predators have learned to avoid.) Indeed, this resemblance is probably why hoverflies are sometimes called “droneflies.”

As you occasionally publish readers’ photos, I thought I would submit the attached. It isn’t a raptor or kitteh but I hope you enjoy it, even if it doesn’t make your blog err website.

It is of a flower crab spider nomming a hoverfly (possibly Eristalis tenax looking at the wing veination). For completeness the flower is a white lilac (Syringa).

I thought it might be of interest as it shows that there is fascinating biology to be seen, even if you don’t live in the Mauritius. I took this photo in my back garden in the village of Cheddar in the South West of England, and what a wonderfully camouflaged ambush predator! One of my friends called it “beautifully sinister”, which sums it up pretty well. I took the photo with a cheap (less than £100) digital camera, which also shows what can be done if you take loads of photos and then shift through for the best ones.

Links for more information on what I think is the right species of spider, Misumena vatia from the Natural History Museum:  http://www.nhm.ac.uk/nature-online/life/insects-spiders/bug-forum/?q=node/182

They can apparently change colour (slowly) to match the flower they are on.

63 thoughts on “Friday natural history: death in the garden”

  2. Fabulous. Now I expect you to camp out waiting to get the actual moment it grabs the next fly! I recognise the hoverfly species (I have photographed it muyself) but cannot recall what it is or check now – can someone look it up?

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      1. Beautiful shot, Ray! I had to really hunt to find the spider (*love* those beautiful crab spiders– does that species really change color? I’d love to find out about that!)

        (thanks, Dominic! Glad you enjoyed the little spider mini-drama 🙂 Here are a couple of Hoverfly shots I got after seeing some stunning ones by Sandy R who also posts to the Encyclopedia Of Life:

        http://www.flickr.com/photos/yokohamayomama/5729488988/in/photostream/

        http://www.flickr.com/photos/yokohamayomama/5719527161/in/photostream/

        Enjoy!)

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        2. If it is like houseflies, it is a male as the eyes are closer together… or bigger? JAC is the fly expert around here though – is it the same with drosophila?

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          8. Look at those pedipalps! Looks like the “street-sweeper” spider to me.

          9. Well, if you’ve got these, you’ll need to do a bit of sweeping to clear away the messy webs and all the crap they accumulate Does that count?

            b&

          12. I thought it might be a freshly molted individual, but wouldn’t have guessed young. I am unfamiliar with such fancy pedipalps in juvenile spiders…

            Is it perhaps a comb footed spider?

          13. No, not a comb footed spider — though you’re definitely getting closer.

            I’d offer another hint…but this spider is so common and notorious that anything more would give it away.

            b&

          14. I’ve been thinking “notorious” since your “packs a punch” comment, but you say this is not a Theridiid…The eyes look wrong to me for the only other notorious spiders I can think of…

          15. Sorry — I think there might be a bit of miscommunication.

            The family is Theridiidae, yes. But (at least, according to Wikipedia), sac spiders are Clubionidae, not Theridiidae….

            Cheers,

            b&

          16. Yes, but…comb-footed spiders are Theridiidae. 😉

            But that’s what I get for using common names. (Yes, they’re also cobweb-spiders, but I didn’t realize you were using that in it’s “official” sense at first.)

            So–some sp of Latrodectus!!

            (In your neck o’ the woods, you probably have more than one?)

          17. Oh.

            I thought “comb-footed” was more specific, not…ah…familial…sorry….

            I suspect we probably do have lots of representatives of that family here. But, rather than giving a more…um…specific hint, I think I’ll retreat back to, “if I gave hints any more specific, I’d give it away” as my hint.

            b&

          18. Did you miss that I gave you a genus? 😀

            But OK; should really Google to try to pin it down, but I’ll just go for the biggie to make it quicker…L. mactans?–[spooky font->](Southern) Black Widow.

            How’d you run across that guy?!

          19. Hm…I suppose I have been known for cluelessness at times.

            But, yup. He’s a young black widow.

            As to where…well, he was in my bathtub. That’s the white background he so obligingly posed against.

            It was quite a challenge getting the shot, too…1:1 macro, handheld, pointing the camera up from underneath at a really odd angle, bouncing on-camera flash off the shower curtains, focussing with live view by moving the (did I mention handheld?) camera…it’s a good thing he wasn’t in a hurry to get anywhere.

            When I was done, I scooped him on a sheet of paper and shook him off out the window. I’m sure he got eaten not too terribly long after…when I finally got around to cleaning up all the moving boxes from the patio he landed on, there were a number of big, fat, black spiders with shockingly-bright-red hourglasses on their bellies.

            They all got relocated to the grass, where I’m sure the lizards enjoyed the feast.

            And I know for certain that a particular copper-colored neighbor cat just loves eating lizards, so I suppose that spider has probably been transformed into a cat. Funny how that works….

            Cheers,

            b&

          20. Well, I expect excellent pictures from you–but congrats–that is a superb image.

            And way cool about the local widow population & food web! (Heh–so to speak…) I hope we’re not the only two left reading this subthread! Sounds like this’d be a great subject for a Backyard Biology/Friday Natural History/whatever post. Just grab some female spider, lizard, & copper kitteh shots. 😀

            (Clueless, ha. I’d kill to be a tenth as clueless as you are. It’s just an artifact of being buried this deep in the comment thread.)

          21. Curse you — now I’ve got a photographic essay to add to The List™ — and several months still before I can even start to think about pretending to chip away at it!

            And that’ll be a doozy of a project, too…probably have to start with a spider nomming a fly, then spider nomming spider, then lizard nomming spider, then cat nomming lizard, and end with a fly on a cat turd….

            Do you have any idea how much work that’ll take?

            I’m not even sure how much it’ll be to catch the lizard in the act.

            Damn.

            Curse you!

            b&

  4. I took the photo and about the mimicry – in fact, when I took the photo I assumed it WAS a honey bee. I only realised it wasn’t when I could enlarge the picture on my computer screen. No idea if I have the species correct (I based it on one wiggly vein in the wing!), the readers here will probably know, though.

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  5. No matter if bee or bee-mimicking Eristalis (which this is); Misumena is also an expert bee-catcher. Indeed, they might be thought of as parasites of the flower/bee mutualism.

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  6. “this hoverfly is almost certainly a Batesian mimic of a bee.”

    I’m with Ray. Without this excellent site, I would have assumed that it was a bee, also. And it took a second look to see the spider. Great photo, Ray! Thanks.

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  7. Also, & Amy note that this is one of your hoverflies, hoverflies like the Episyrphus balteatus, are attracted to pea aphids by a bacterium in the aphid honeydew, which acts as a ‘kairomone’ (see wikipedia).
    http://orbi.ulg.ac.be/handle/2268/93528

    And talking of Batesian mimicry, flowers do it too – with pheromones – to attract hoverflies!
    http://rspb.royalsocietypublishing.org/content/278/1709/1216.short

    So, why are hoverflies as a group so very good at Batesian mimicry? This page might say but no time to read it now!
    http://www.microscopy-uk.org.uk/mag/artmay07/cd-hoverflies.html

    It is a war out there…

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      1. Why do all flies not end up as mimics, eg Musca domestica etc? There must be a cost to it. Maybe some chemical is required for the colour that is expensive & not available to flesh eating flies? Anyone know?

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        1. Well, one potential reason is that a housefly wouldn’t be a convincing mimic for behavioral reasons. Hoverflies spend a lot of time getting nectar from bee-pollinated flowers. That is, in the course of making a living, they act much like bees. Houseflies, not so much.

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  8. Flower flies is another common name for the Syrphidae, and it seems more natural to me than hover flies because members of the family are most often observed visiting flowers. The Bug Guide web site sidesteps the issue, though, by calling them syrphid flies. A search on Bug Guide for “crab spider and prey” brings up a suite of about 80 images, so there would surely be many more than that on the site which that particular search term wouldn’t find. Some of the crab spiders can vary their colors to some degree in accordance with those of the flowers they lurk on. Here’s one on a yellow flower clutching an ichneumonid species that is a parasitoid of larvae of flower flies that feed on aphids–an entire subfamily of Ichneumonidae shares this habit. Here’s another crab spider that is not on a flower but has a flower fly in its grasp. In late summer or fall, a convenient place to observe or photograph crab spiders and prey are the flowers of Queen Anne’s Lace, which are familiar to many.

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  11. That white spider is beautiful in the most nightmarish way. Thanks for shudder and goosebumps. Brrrr.
    I’ve never seen all white spiders like that in Denmark, but we do have a few very pale ones – the one that springs to mind is a recent import from Spain, Pholcus phalangioides, which has settled with extreme succes here in the north sine the 1980’ies. They are everywhere, and make very untidy webs. tsk.

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    1. That is interesting – I assumed they were a European native but the Wikipedia page (not very useful) says they are ‘from the tropics’ with no citation. We have had them all my lifetime – the most common indoor spider. The webs get annoying if it is a while since you have been in a room, & I think they are easy to transport when you move house but while I sometimes eject them when I had ants in the kitchen they did a good job embalming them like little Egyptian mummies. The way they shake reminds me of Elvis.

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      1. They are fast becoming the most normal indoor spider here as well, but they were quite the novelty 25 years ago. I find them slightly irritating, but they are very efficient hunters indeed!

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  12. Ahh, hoverflies! I really don’t like flies, because they are a) usually into dirty stuff b) loves my body odor – I’m most always the first to get bitten by an intruding horsefly at the beach.

    But hoverflies I like, they are beautiful and harmless … oh, wait: “The drone fly is reported to have caused accidental myiasis, … The larvae are able to survive gastric fluids, possibly due to the fact that they are adapted to living in polluted habitats (Aguilera et al. 1999).”

    Another organism that I can’t stomach! Great, now I don’t know whether to like or abhor them. :-/

    @ TrineBM:

    I don’t see why you shouldn’t see white crab spiders in Denmark, we have them in Sweden!? (Seems miscellaneous crab spiders live all over the world, including arctic regions.)

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  13. I encountered a bee-mimicking hoverfly in Georgia a short while back, and while it certainly looks a lot like a bee, I’m not sure I’d say it behaves like a bee.

    First, there’s the hovering, which the little blighter does very well, while bees do nothing of the sort. Second, there’s the odd way the fly tracks you, keeping you in front; going forward when you back away, and backwards when you move towards it.

    What animals actually avoid hoverflies because they resemble bees? I’m genuinely puzzled, since the only one I can think of is my own species. Insectivorous birds seem to care not one whit for the presence of a stinger (real or imagined) on their prey.

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    1. Can the predatory wasps distinguish them from the bees they parasitize? Would it matter to them if they did or not?

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    1. Thanks! By the way, if it looks from the timing of my posts that I have been up half the night, I have – noisy chav neighbours with a karaoke… still going at 10am… grrrr – want giant misumena to eat them!

      Reply
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