May 16th, 2007
in search of young spiders
Each year, I try to choose a few small projects to work on over the spring through autumn season. Most of the projects have to do with observation of insects or spiders, although some have to do with photography. One of my projects for this year, is to try to learn more about young spiders and insects by watching for them earlier in the season. When I first became interested in these creatures, I seemed to have my hands full just figuring out who was who. Gradually, I’ve come to be able to recognize quite a number of them, or at least be able to figure out roughly who they are (family and genus) if I spend a few minutes checking my field guides or favourite websites. The ability to identify creatures has gradually led to a desire to know more about the appearance and behaviour of them at their earlier life stages. That takes a bit of extra work, both out in the field, and once back indoors flipping through my books. Creatures that are easy to see in July or August, are often of miniscule size in May or June, and they may not be hunting in their familiar places. For example, consider the various Flower Crab Spiders such as the three images in this post. Later in the summer, most can easily be found by examining many kinds of wild flowers. But where are they earlier in the season when there are less flowers around?
I gave that some thought yesterday morning and spent time searching on dandelion flowers, and also checked out flowering trees. Sure enough, I found several very small spiders (click on all images for larger views). So, this is where they hang out until they get large enough to stake out a whole flowertop later in the season! Of course, the other question that comes to mind is, “What do these little spiders eat before they are ready to tackle honeybees and other large insects?” The above spider gave me some clues to that. It was grasping some type of very tiny fly. You can see one of the “halters” (a knobby little thing sticking out from the wing attachment area) which reveals that this is a fly (Diptera) and not an insect of another Order.
The search for young spiders and insects ties into another of my projects for this season, and that is to try to gain a better understanding of the relation between creatures and certain plants. Over the past couple of years, I’ve come to understand quite a lot about the communities of invertebrates that live on Milkweed plants, but that’s through spending a lot of hours studying who hangs out there and what they’re up to. This spring, I’ve spent quite a few hours searching the bark of poplar trees and have a pretty good idea of the community of creatures that are wandering about in April and May. I’ll try to continue to watch throughout the season, and will also try to add a few other plants to my observations – for example, Salix (willows) have many insect associates.
All of the above kinds of observations contribute to my overall understanding of the ecology here at the farm. I believe it takes many years – perhaps much more than a lifetime – to truly appreciate even a fraction of the connections that are taking place in the natural world . The more that I learn, the more complex it all seems. In the past, I’ve described nature as being like a tapestry. That seems as good a metaphor as any for visualizing the many different strands that combine to produce even the simplest biological community.
[tags]Thomisidae, Flower Crab Spider, Misumenops, Misumenoides formosipes, Misumena vatia[tags]
May 16th, 2007 at 12:14 pm
Beautiful photos… are the “halters” the little “pseudowings” behind the regular wings? I’ve seen those on Crane Flies before.
Having a bit of arachnophobia, every year I inevitably get a crab spider or two crawling on me while looking at wildflowers.
May 16th, 2007 at 12:24 pm
Patrick – Thanks! Yes, the halters are the pseudowings behind the regular wings. Unlike most other insects, Diptera just have 2 wings and a pair of halters. Their purpose is generally believed to assist in flight stability, etc.. Stephen Marshall, in his book, Insects: Their Natural History and Diversity writes:
Don’t let yourself be too nervous of crab spiders as I don’t really think they would bother a human too much. I find that they are very shy and will do just about anything to avoid a human-spider encounter! (-:
May 16th, 2007 at 7:41 pm
I’m about to pass my computer over to my husband to show him your UNBELIEVABLE! photos. Sorry to gush, Bev – but these are just beyond awesome. I’m going to click on these beauties and savor. These pictures make me so grateful for the mystery and beauty of this miracle planet.
May 17th, 2007 at 6:07 am
With all the trouble I’m having with the (apparent) adults I see, I can’t imagine trying to figure out the babies!
The crab spider photograph is just great, Bev.
I had just run across a discussion of the halter function as “gyroscope”, or balancing, the other day. What a neat substitution of function of a pair of wings that aren’t needed.
May 17th, 2007 at 6:42 am
Cathy – Thanks! I probably don’t need to tell you that each time I come in from shooting photos, I can’t wait to download my camera and get a better look at all of these little creatures. It’s like peering into a whole other world. That’s pretty darned exciting if you ask me.
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Wayne – Thanks! and yes, for sure — I believe the smaller spiders don’t have all the same markings as the adults. Other insect nymphs look radically different from the adults – stinkbugs are a good example of that.
May 19th, 2007 at 2:42 pm
Amen about the complexity of the natural world. Son Steve is trying to enlighten me more about the insect world, but there are so many! Sounds like I’ll have to get both the Marshall and the Kaufman books, and just when I thought I had enough field guides (Kaufman).
May 20th, 2007 at 9:19 am
Marcia – The Marshall book is a huge tome with many beautiful photos. I think you would find it of great interest if you can make room for it on your book shelf. The Kaufman book, while light on text, it a very handy little guide and I’ve already made use of it several times this week.
May 22nd, 2007 at 7:46 pm
Once again, wonderful spider close-ups! I try to take arthropod shots myself, and you have been an inspiration to me.
May 23rd, 2007 at 5:17 am
Larry – I’m glad to hear that you’re inspired by my spider photography. Of all the photography that I do, I find that insects and spiders are about the most fun of all.