Friday Spider

Now that the goldenrod is blooming I've been looking for a yellow goldenrod crab spider doing what its name suggests it should. This morning I found one, mature, yellow and working the goldenrod--just in time to board the Friday Ark.

If it hadn't been for the fly in her jaws I probably wouldn't have seen her.

Three Crab Spiders

After a quiet period there's been quite a bit of singing lately as the birds who nest again started getting ready. So I was determined to get out for a bit of birdwatching. I did, and saw lots, but everyone looked so big! A common yellowthroat, really? It looks the size of a finch. And gradually I realized that it's the spider eyes. I am learning to pick out spider types by GISS, pulling me into tiny world.

In the far field I saw these three. Two on milkweed, one on brown-eyed susan. One was Misumena vatia (Goldenrod Crab Spider), but the other two?

Goldenrod Crab Spider on Milkweed
One was clearly something quite different, the other just a little different.

A spider of another colour

Not M. vatia, I think, but something related
I did some research, in part by checking out Bev's (Burning Silo) Crab Spider Gallery, but couldn't find a match I had any confidence in. Looking at a recent post of Bev's, possibly the last one is Misumenops asperatus.

Lovely spiders whoever they are.

More from Rugosa World

A July bioblitz of the Rosa rugosa alba in the yard would take hours and hours, and could be done every day and produce new results each day. And this rose bush, about 2 metres high and almost as wide, is mere steps from the front door.

I've been watching a number of Misumena vatia over the past few weeks (inspired by Spider WebWatch). These spiders, ambush predators, stay in one spot for extended periods, making them excellent subjects for long observation. I can see what they're eating, how fast they're growing, and even guess as to when they're pregnant, and then eventually see their egg cases. There's one on the Rugosa now I've been watching for some time that has a prodigious appetite. She moves occasionally as blooms come and go and I can usually find her again by looking for the sucked-dry rose chaffers she's dropped onto the leaves below her chosen spot. This morning she has a moth, and twice now she's had a small bumblebee, which surprised me: small, but not compared to her.

Misumena vatia at Lunch
So there I am, staring at the rose bush, looking for spiders, and now that I'm developing an eye for them I'm seeing that there are many other spiders (and many other critters all together) living there. I was startled by the one below because of its white abdomen. Most of the M. vatia I find on the bush are white, so that's what I look for in a scan, but this little one was no crab spider.

What long, spindly legs you have
The spider is sitting just below a developing rose hip (not an apple), and in the upper left of the picture you can see the leg of the rose chaffer it was wrapping up when I first spotted it, which gives an idea of how small this spider is.

I couldn't see a web, just a few random strands of webbing, and the obvious silk production and webbish behaviour of wrapping prey. I hunted around for an ID, gave up and sent an image to BugGuide. In very short order I had a response (click on the link to see just how short). Take a look at Enoplognatha ovata, a member of the cobweb spider family. I did, and I think they got it!

I really think it is Enoplognatha ovata

Misumena vatia

One of the ambassador spiders at Spider Web Watch is the Misumena vatia, or goldenrod crab spider. So far, I've observed ten different individuals of this lovely species, seven of which are living in the front garden. Below a sampling. The first two are spiders I found at the near edge of the far field. The rest, garden dwellers, in a sequence: small, smaller, smallest.

In the late afternoon sun, having a snack
Tiny, brave, on a buttercup
Waiting on a shasta daisy
Enjoying a fly on a shasta daisy
Just a white speck, snacking on a dark speck, that turned out to be a tiny fly

Some of the juveniles (i.e., photos 1, 2, 4, and 5) might be Misumena formosipes. Take a look at the page at Spider WebWatch (and this discussion) to see the diffculties involved in distinguishing these from vatia.

Yponomeuta cagnagella

About a week ago, after one of the little hot spells that this spring has been rife with, I noticed that the wahoo in the yard had been completely stripped.

Eastern Wahoo (Euonymus atropurpureus), stripped
It was entirely covered in webbing, revealing the culprit to be the euonymus caterpillar, larva of the spindle ermine moth. This is a specialist in the spindle bush, a European euonymus, and came over here with that shrub. Once it got to North America, it found that there was another shrub already here that tastes just as good.

Yponomeuta cagnagella (Euonymus Caterpillar)
Last year, as I wrote here, this wahoo was badly infested, but not stripped. But Yponomeuta cagnagella is so specialized that it not only feeds on that special euonymus, it also cocoons there, and then apparently returns to lay its eggs there. We have three of these around the property--this one in the front yard, one back further in the growing young forest, and one in a far corner, nestled into a growing lilac hedge (it wasn't planted that way, but the lilacs are doing very well). The more central tree had a few of these caterpillars on it (easily removed), the one in the far corner was completely covered by them, but these had hatched a little later (further north, don't you know). That tree is only half eaten, and I spent a good hour each day yesterday and the day before removing caterpillars. The caterpillars spend a great deal of time huddled in masses, inside their webs (particularly in the morning when it's still pretty cool), so are pretty easy to pick off the branches in handfuls. Saturday, I was tossing them onto the road, yesterday I had a nice pail of soapy water for them. Yesterday I picked more than a litre of the critters. Some remain because they were out of reach--I'll be out again in the hopes that they will collect lower down.

The soapy water method (dish soap) works very well--and when you can toss them into a bucket, instead of washing down the tree there's no risk to the tree--the soap will burn the leaves of some species if left on too long.

The stripped tree is the most interesting case--infestations such as it had are good for no one. I found no cocoons on it, and lots of clumped together caterpillars, not yet full grown, slowly starving, having eaten their entire food supply. Lots of them had also moved to the adjacent Norway maple, to huddle and starve--they can't (won't) eat maple leaves. These guys get around on silk ropes, and apprently can't get back to the tree if these are broken, nor it seems can they travel any distance to find a new host--perhaps have no way of discerning one. So I think the danger to this particular tree is over, if it survives. I am concerned that the sticky webbing in which it is covered will hamper its efforts to leaf out again, which will reduce its chances for survival. During the soapy water attack on the caterpillars on the other tree, I noticed that the stickiness of the webbing is completely defeated by the detergent. Webbing and caterpillars stuck to my hand dropped right off when immersed in the soapy water. So I am considering washing down the stripped tree with soapy water in the hopes that at least some of the webbing can then be rinsed off with a blast of the hose.

Misumena vatia
I tried a variety of techniques for vanquishing these caterpillars, including exposing them on rocks, and as mentioned, throwing them on the road, to see if anyone would like to eat them. I did see an ant bite one of the ones on the rock, but don't know if it ended up killing and taking it. And I watched the spider above grab hold of one a few times, and apparently decide that it wasn't for her. Another condition necessary for an infestation such as this one is that there are few or no predators, which may well be the case here.