a little special

Earlier this week, I posted several photos of female spiders guarding egg cases. Yesterday, I found yet another to add to my records. This spider is a Misumena vatia, a member of the Thomisidae Family (crab spiders). She’s a little special for a couple of reasons. It happens that she’s the first of this species that I’ve seen making an egg case here at the farm in 2007. I’ll see many more this season, but it’s nice to record a “first” date for this species. The other thing that is a bit special has to do with her markings (click on image for a larger view). Most females of this species have a pair of lateral pink to red bands on the abdomen. The rest of the abdomen is either white or yellow depending on whether the spider is in a white or yellow phase (these spiders gradually change their colour as they move between yellow and white flowers). Here is a photo of a typically marked spider. The spider that I found yesterday has an extra set of bright pink markings on the top of her abdomen. In checking through my images of this species, it looks like the only other similarly marked spider was photographed here at the farm on July 7, 2003.

Yesterday’s spider had made a chamber for her eggs within the folded central leaf of a Common Milkweed plant (see below). After folding, the leaf is carefully sealed with silk. Some spiders create such chambers and then hide within. However, I’ve found that most Misumena vatia remain on the exterior, perching upon it, or clutching their long raptorial legs around the chamber if they perceive any kind of threat. In a post that I wrote about these spiders back in January, I mentioned that I have observed these spiders staying with their eggs for weeks until they become desiccated from lack of food. I suspect that some must eventually expire while maintaining their vigil.

Misumena vatia is one of the nine species of spiders being tracked on the new Spider WebWatch citizen science site. If you happen to see one of these spiders, or any of the other eight spiders that are part of this program, please do enter a record, or better still, upload a photo to accompany your data. The site is easy to use and it just takes a moment to register so that you can begin entering data. It’s great to see some records now appearing in the database, especially for this species.

Reminder: Tonight is the deadline for invertebrate posts to be included in the upcoming edition of Circus of the Spineless. If you have a post that you’d like included, please email me.

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11 Responses to “a little special”

  1. David Says:

    Nice shots Bev! At first I was unsure if your M. vatia might have been a Misumenoides formosipes and I wrote a little comment on your observation to seek your confirmation. Here’s your observation & my comment: http://www.spiderwebwatch.org/comments/Misumena_vatia/29/

  2. bev Says:

    Hi David – Glad you stopped by for a visit. I’ve just posted some notes at Spider WebWatch concerning this sighting. I’ll have to go and take an even closer look at this spider, but I’m pretty sure she’s a somewhat unusually marked Misumena vatia rather than M. formosipes. I’d say that her face area seemed typical – rounded rather than angular or flattened (from what I can tell, M. formosipes has a sort of flat head with squarish face). I only have one photo that seems to show this spider’s face (not a great shot), but if I can re-find her, I’ll try to get better images. Anyhow, here’s the photo as large as I can make it without losing too much detail (see below). In other respects, I’d say she would be a typical M. vatia — she’s at the large end of the scale for size. The colours seem typical, and Morse’s book does say these kinds of mesial lines are seen, just not common. An entire “V” is also possible, but he says that is extremely rare. I guess that, with all of these spiders I have photographed over the years, I might meet up with the odd one with unusual markings. Then again, perhaps she’s actually an M. formosipe and just has me fooled! (-:

  3. Cathy Says:

    Vatia or formosipe – this is a fine, fine spider! I love the rippled effect that runs the length of those pink stripes when I click on it. For some reason it reminds me of something edible: a confection of some sort. Just can’t place it. (I guess I’m hungry:0)

  4. David Says:

    That’s a much better shot & I agree,that’s M. vatia. For anyone else who might be interested, I posted a few links to some really nice BugGuide images in the little discussion here that show the two species’ eye areas (more specifically, just under the eye areas) up close.

  5. bev Says:

    Cathy – It’s a gorgeous spider. I just went back out to do my insect walk in the fields and did manage to re-find her and take more photos. She’s splendid.. and yes, the way her body has the wavy texture in the pink stripes does look like piped icing on a cake or something. I was struck by that when I was examining the latest group of photos. Looks kind of yummy — perhaps I’m thinking ahead to the birthday cake we’ll be having tonight at my mom’s house!
    David – thanks for taking a look at that shot. I took a few more photos in which I attempted to get a better head shot. Of them all, I think this one might be the best, and I’d have to say it looks like M. vatia to me. Thanks also for posting links to the discussion and the BugGuide images as others may be interested in some of this stuff.

  6. bev Says:

    Cathy – One thing I should have mentioned about the ripples on the spider. Quite often female spiders will look very wrinkled after they have laid their eggs. This is very noticeable in the large garden spiders (Argiope aurantia). After making their egg case, they look a bit like a deflated balloon. I think that’s what has happened to this spider as well. Interesting, no?

  7. robin andrea Says:

    Yes, she does look like something quite yummy. A sweet confection. What a beautiful spider. Nice details, bev.

  8. Cathy Says:

    I’ll be looking more closely. You know, Bev, I’d never have guessed that I’d find myself being disappointed with the paucity of spiders in my environs. But here I am – searching the garden and wondering where the spiders are.

  9. Cindy Says:

    a million thanks for doing what you do..you remain my favorite and for good reason :)
    amazing photos/info as always my friend..I don’t think you realize how very much you expand my world right now.. an incredibly magical world thru Bevs eyes- doesn’t get any better.

  10. bev Says:

    Cathy – It’s still quite early in the season, so just keep watching for these and other spiders. Milkweed is always one of the very best plants to watch for insect and spider activity. Larger female Misumena vatia should soon be visible on many garden flowers such as the centers of the more open old-fashioned roses such as the rugosas. Daisies are a favourite perch as well. Sometimes I find these spiders when I see a fly or bee that doesn’t move away when I approach a flower. The cause is often that it has been captured by one of these spiders. They really are nearly invisible when perched among the petals of flowers. I have to say that it seems like there aren’t as many spiders as usual around here too, but perhaps I’m just a little early with my expectations. By the way, the other day you remarked on having a moth climb onto my hand when I wanted to bring it in from outside the window. On somewhat cooler nights, moths will readily climb onto your hand if you hold it out where it can walk onto it. They do seem to like the warmth and will often stick to your hand until you push them off. It’s kind of fun to watch them walking around on your hand, often with wings madly flapping.

    Cindy – Good to see you stopping by to visit again! Thanks about the photos. I’m glad that they bring some enjoyment and allow you to see some of my little world here at the farm. (-:

  11. celeste Says:

    Hi! I really like that top picture, with the bends of the legs and the pretty red with the grey of the leaf hairs ;0)