Readers’ wildlife photos

Reader Mark Sturtevant, a crack photographer of arthropods, sends some photos he took last summer. His notes are indented:

Spiders are generally rather good parents since they guard their eggs and young for a time. The first four pictures are about the nursery web spider – so the very name of these spiders suggests their caring nature. This species is Dolomedes tenebrosus, which may be the largest spider in the U.S. that is not a tarantula. Besides being big, they are also very fast in short bursts. Females carry the egg sac under their body, gripping it with their fangs as we can see in two of the pictures. This spider was sitting on the porch of my brother’s house last summer, and my brother snuck a picture of me taking a picture of her so I also include that as well. At the time I was probably hoping that these spiders are not jumpy.

The last picture of this series was of a different spider, and here we see the next stage of their nurturing behavior. When the babies are ready to emerge from the egg sac, the mother attaches the sac near the top of a plant (frequently near water), and guards it while the babies emerge and later disperse. Although these are Spiders of Unusual Size, they are actually pretty easy to get along with. But will I pick one up? No, I will not.


Continuing with spiders for just a bit longer, the next two pictures show a lovely male jumping spider called the bronze jumper, Eris militaris. ‘Eris’ is the Greek goddess of discord and strife. The males of this species have a metallic sheen to much of their body.

Here we have of the most bizarre looking insects: the pelecinid wasp (Pelecinus polyturator). I do not consider these to be common, but in my favorite park where I have found many wondrous things, there was a period where I would see 3 or 4 of them in a day. Although rather large (they are up to 7 centimeters long), they can be surprisingly hard to see. They have a slow and languid flight that is completely silent, and in a second their spindly form simply disappears into the broken light of the forest. At rest they look to be an easy subject for photography, but no, they would always slowly lift off and disappear just before I could get in range. So I resorted to catching this one and getting its picture in a staged shot at a window indoors.

So what about their biology? This too is unusual. Some authorities consider the entire family to consist of a single species—but not everyone agrees with this. They are parasitic on beetle grubs, and their most common hosts are the larvae of ground-burrowing June beetles; the females use their extraordinary abdomens to probe into the soil to lay an egg on their victims. But the unusual thing is that the vast majority of these wasps in the U.S. are female (males are rare), and so up here [Michigan] it seems likely they reproduce mainly by parthenogenesis. Males are more common sin the southern U.S., and one supposes they reproduce the usual way down there. The link to the species name has pictures of males in case people want to see them.

I end this set of pictures with a grasshopper that would be hard to see in a Spot The ________ contest. This is the pine tree spur-throat grasshopper, Melanoplus punctulatus. I probably would not have seen this one except that I grabbed a tree trunk when I had stumbled and happened to look down. The ‘hopper remained perfectly still and let me take all the pictures I wanted, perhaps relying on its camouflage. A thing to note about this species is that its main diet is tree leaves.

13 Comments

  1. Glenda
    Posted August 1, 2017 at 8:15 am | Permalink

    Thank you for wonderful photos and notes. Fun shot of you taking the photo.

  2. Sam Tiamsah
    Posted August 1, 2017 at 8:43 am | Permalink

    Very nice photos!

  3. rickflick
    Posted August 1, 2017 at 11:36 am | Permalink

    That’s an extraordinary wasp! I wonder if that long abdomen carries out digestion and excretion as well as doing the egg laying business. If so, that’s one crazy digestive system.

  4. Michael Fisher
    Posted August 1, 2017 at 12:36 pm | Permalink

    Stephen Fry on parasitic wasps & god [2 minute video]: https://www.youtube.com/watch?v=i4UzH-xoS7w

  5. Heather Hastie
    Posted August 1, 2017 at 3:53 pm | Permalink

    Great pics Mark!

  6. darrelle
    Posted August 1, 2017 at 4:14 pm | Permalink

    Another great batch of pics Mark. I’ve never seen anything like that wasp. Also, you are a brave man risking your life like that to get a close up of a potentially man eating spider.

    • Mark Sturtevant
      Posted August 1, 2017 at 6:05 pm | Permalink

      Having many more encounters with them, I have decided they are really predictable and shy. I won’t pick one up, but I will nudge them to get them to go where needed for pictures.

  7. Mark R.
    Posted August 1, 2017 at 4:14 pm | Permalink

    These are all terrific. I am always pleased to see a batch of Mark Sturtevant photos because I know I’ll learn something.

    When you say the grasshopper’s main diet is tree leaves, are you referring to live or dead leaves?

    • Mark Sturtevant
      Posted August 1, 2017 at 6:07 pm | Permalink

      They eat live deciduous leaves and pine leaves, and like this one they are commonly found on tree trunks. I guess they are tree grasshoppers (?).

  8. Posted August 1, 2017 at 5:01 pm | Permalink

    Glad your brother took the shot of you. Yet one more reason not to become a wildlife photographer!

  9. Diana MacPherson
    Posted August 1, 2017 at 6:46 pm | Permalink

    Dolomedes tenebrosus – the reason why I don’t go up north anywhere near a dock.

  10. Posted August 2, 2017 at 4:32 pm | Permalink

    Very good, thanks for the pics and info.

  11. Posted August 3, 2017 at 5:52 pm | Permalink

    Very cool Mark! I’m an indoorsy person mostly, but I never see some of these guys in southeast Michigan. Are you farther north?


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