Tasmania – Millipedes from the blueberry patch mulch

2014 February 12

After the sweep through the house, my dad said that if I really wanted to find lots of little creatures, I should go down to the blueberry patch and look under the mulch around the plants. So, off to the blueberries I went! The mulch was sheets of newspapers with moist wood chips, bark, and pine needles on top, so all I had to do was push aside the top layer to expose the newspaper, or peel up the newspaper to expose the soil underneath. There were a lot of things under there, so let’s start with the several kinds of millipedes[1]

This white one would have been a bit over an inch long, if it had ever uncurled.

It popped out a fecal pellet while I was handling it, but I don’t know if this was a standard defense mechanism, or if it just really had to go[2]

Since it had a dark stripe running down its back, I’m pretty sure that white was actually its natural color, and it wasn’t just pale due to having recently molted.

A lot of these small leaf-litter creatures were pale, probably because it is dark in the leaf litter and camouflage would be pointless. This millipede was also white, but is clearly a different species because it has no black stripe, and reddish-brown spots on its sides.

Not all of them were white, though. This one was actually quite gaudy, for a millipede.

That red racing stripe probably indicates that this is one of the more toxic millipedes. A lot of them are loaded with chemical defenses, like cyanide.

Next to the red-striped one, you can see a much smaller creature that is pure white. I don’t think it’s a millipede exactly because it doesn’t have enough legs, but I don’t think it’s a proper centipede, either.

It appears to be a Symphylan, which are little myriapods that are in a class by themselves. Unlike the carnivorous centipedes, these are omnivorous debris-feeders. The ones I was finding weren’t very big – in the next picture, you can see it standing on my fingertip, and it is only about 6 fingerprint-ridges long, or less than a quarter-inch.

Here’s another individual of probably the same species. The much larger white spheres off to the right side are most likely slug eggs.

I thought the white, obvious individual in this next picture was another myriapod at first, but looking more closely I think it is actually a pale springtail.

The black, shiny objects are kind of cryptic. I tried zooming in on them and enhancing, but I’m still not sure what they are. In close-up, they look like a large sphere with varying numbers of smaller spheres clustering around them, so my initial guess of snail eggs is probably wrong. Maybe they are fungus fruiting bodies of some sort? Or droppings? Anyway, in the course of zooming in I got a better look at yet another small myriapod-like creature. It doesn’t quite look like the Symphylans, the antennae are too short. At first I thought it was a Pauropodan, but I was advised down in the comments that it is more likely an immature springtail in the family Hypogastruridae

This was quite a haul as far as myriapods go, I seem to have added at least two entire classes of myriapod all at one go!

[1] Tasmania seems to have a much broader range of millipede species than northern Michigan does. I found as many species of millipedes in five minutes of mulch rummaging as I found in Michigan in the last six years. This is probably because the Michigan millipedes all got wiped out in the last ice age, and in the 10,000 or so years since then they just haven’t had time to walk back. Tasmania had an ice age, too,, but not like Michigan’s – the Tasmanian ice age amounted to a bit cooler, a bit drier, a direct land connection to the Australian mainland, and some glaciers up on the mountains. A far cry from the mile-deep ice sheet that was busy plowing up most of Michigan at that time.

[2] One could say I probably scared the crap out of it.

2 Responses
  1. Andy Russell permalink
    April 14, 2014

    Hi- Cool site. Just for your info, the last pinky/purple animal in your photos is actually an immature Hypogastrura species springtail. The larger whitish one next to it is one of the Onychiurinae species of springtail, a very common soil dwelling springtail. Pauropods tend to be white unless they’re eurypauropods and they don’t have ocelli/eyes…!

  2. April 15, 2014

    Thanks, Andy. I just revised the posting with your correction.

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