Lumpy, bumpy, orange spider

I almost stepped on her. A fat, orange spider was parked right beside my work chair; when I turned to go for a coffee, my foot missed her by a couple of inches. She didn't even move.

She barely bothered to react when I put the camera down a few inches from her eyes. Trusting soul!

I took more photos. She turned her back on me. I don't think she liked the flash.

"Knees up, Mother Orange!"

I think she's a Marbled Orbweaver, Araneus marmoreus, an extremely variable species, but the eye placement is right, and the pattern of legs and body fits. And these spiders hate the light.

An interesting exchange on BugGuide:

"While focusing I noted that the round protruberances on her back were pulsating. Are these respiratory?..."
"Yes! ... I've noticed the pulsating as well. I believe it is a defense mechanism. ... It could be that they are trying to produce silk so that they can 'web' away from me.
But as I originally said, I think it's just a defense mechanism. Perhaps to make them look larger to predators."
… Nikole Loomis (Bush Cricket and Buckeye Lover)

When I was done, I shooed her off towards a corner, where she could safely lay in wait for the next passing harvestman. I went for the coffee, finally. When I came back, there she was, sitting patiently beside my chair again. Time to deport her!

In an Ikea glass, waiting to be moved.

I put her outside, in the rain. And it turned out that was a lucky move. That white powder on her pedipalps in the first photo? I realized that it was the remains of some diatomaceous earth I'd spread around in the hot days of last summer, when we had been invaded by fleas. I had vacuumed it since, of course, but there's a bit still hanging around in the back of my closet. And it's a spider killer, too.

Although it feels much like talcum powder to humans, diatomaceous earth is actually jagged, and when spiders walk across the powder, it begins to jab and cut into their hard exoskeleton. According to the Oregon State University, the wounds created by the jagged diatomaceous earth cause the spiders to desiccate, or lose all of the liquids and oils from their bodies. This desiccation eventually leads to death. (From sfgate)

It's a slow killer. It takes a spider two days or more to dry out and die. However, if it rains, or if the ambient humidity is high (like anywhere outside here, these days) the diatomaceous earth slides off, and the spider lives.

And fortunately, "Mother Orange" had collected it on her pedipalps and some of her feet; most of her skin was clean. I think she'll live.

Mini Pirate

A tiny spider walked down my wall. I was busy and barely noticed until it was right in front of me, when I saw that it was oddly proportioned; the head end* was larger than the belly**. (*Cephalothorax and **abdomen.)

The camera saw it better than I did. The belly was an odd shape, as well as being too short.

A Pirate spider, probably Ero canionis.

I had never seen one like this before. I sent the photos in to BugGuide, and they, as they do so well, identified it overnight as one of the Mimetidae, the imitators.

Long, spiky legs, short, flared "skirt".

The pirates are spider killers. They invade other spiders' webs, and vibrate the threads as if they were insects caught in the web. When the owner investigates, the pirate leaps and bites her in the leg.

Spiders extend their legs using hydraulics, rather than muscles, as we do. To run, they increase the pressure in the cephalothorax (the head/upper body section), sending blood down the legs. Small muscles then return the liquid to the body, returning the legs to the relaxed position. So a shot of paralyzing poison to the legs soon invades the whole body. (Fang)

Mimetids are equipped with a spider-specific venom that paralyzes their prey almost instantly. (SpiderBytes. Interesting story on this page.)  

Evidently, a bite to the abdomen takes much longer to act. But the spider "knows" this, and heads for the legs.

My tiny pirate ran down behind a cabinet and was lost, but I'll be watching out for her. I'd like to see her in action.

Successful rescue

I've been watching a pretty brown spider just outside my door. The other day, she had a new meal, a green grub of some sort.

As found, all tied up.

When I was taking its photo, it moved, struggling feebly against the web.

Sorry, spidey; this one's mine. I pulled the critter out of the web with an eagle feather I keep on hand. It took some doing; that's a very sticky web!

I thought my efforts may have hurt the grub, but after a rest, it stretched out and walked away.

Interesting stubby feet in the centre. And big, staring eyes.

Nibbling at the foamy I had it on. "Nah! Not edible!" And off he went.

I couldn't identify this, and sent it in to BugGuide. It's a sawfly larva, in the Tenthredinidae family. Jeff Brown, the BugGuide contributor who identified it, wrote,

"You can often differentiate Sawflies from Caterpillars by the prominent eye spots and the number of prolegs."

The legs are the first three pairs of walking legs; these will be retained in the adult sawfly. The prolegs are the stubby pegs that are visible in the coiled photo. This grub has 7 or 8 pairs. Butterfly caterpillars have variable numbers, up to 6 pairs. The adults, of course, have no legs, pro or not, on the abdomen; the 6 adult legs are attached to the thorax.

A proleg is a small, fleshy, stub structure found on the ventral surface of the abdomen of most larval forms of insects of the order Lepidoptera, though they can also be found on other larval insects such as sawflies and a few types of flies. ...
... Although the point has been debated, prolegs are not widely regarded as true legs, derived from the primitive uniramous limbs. Certainly in their morphology they are not jointed, and so lack the five segments (coxa, trochanter, femur, tibia, tarsus) of thoracic insect legs. Prolegs do have limited musculature, but much of their movement is hydraulically powered. (Wikipedia)

I released my grub outside, a good distance from the spider's corner. The spider sulked overnight, then rebuilt her web from scratch.

Two caterpillars: a question of numbers

Everywhere we go, these days, we find more caterpillars. Most match one of these two:

Silver-spotted Tiger moth, Lophocampa argentata, found climbing our wall

I couldn't identify this right away, and planned to send it in to BugGuide, but I did my homework first; no sense giving them more work than I need to.

Limiting my search to immature moths, which includes eggs and chrysalises, I found 26,875 photos in the image file on BugGuide. Too many!

I switched to butterflies. Not because they were more likely, but there were only 4,375 photos of immatures. I looked through them all. No match. Back, reluctantly, to the moths.

We see Orange Underwings around here most years. And there were only 175 photos of immatures. But, sadly, not these guys.

I backed up the chain, to the Noctouidea, the night-flying moths. Only 14,175 photos to scan. And I think I've found my target, in the Tiger Moth category (4,150 immatures). And to confirm, I've seen an adult or two around here.

Unidentified caterpillar, at Elgin Heritage Park.

For this one, I started looking in the Tiger Moths. And it seemed that I might be on the right track, until, about 1500 photos in, I found a few similar ones that the experts were not sure of.

That's a good enough excuse for me to quit; I'm sending this one in.

Untangling a crumpled fly

Laurie brought me a miniature fly that he found in the sink. It was difficult to capture, and didn't survive. By the time I got it, it was all crumpled up, and shedding bits.

I've spent the better part of two afternoons and nights preparing photos for BugGuide; shooting, sorting, selecting, cleaning up, resizing, renaming. And then deciding they're not good enough, and starting another shooting session. My eyes are burnt out, and applying for personal time off.

I soaked the fly in hand sanitizer to soften it*, and photographed it between two sheets of glass in the goop. Most of the photos were totally unusable, but by putting the light behind it, and off to the side, I got a few shots passable for identification purposes. I hope.

It was just too bad that all my sheets of available glass were so badly scratched; I spent hours removing scratches and pretty bubbles of air stuck in the goop from the background. I left the ones in and between the legs of the fly itself.

This photo is the only one of hundreds that showed the halteres clearly. They're a different shape than I expected.

Silhouette, showing venation of the wings. The fly is 4.5 mm long.

And now I'm too tired to finish the job by filling in the BugGuide forms. I'm going to bed. There's always tomorrow.

*I used a variation of Dragonfly Woman's method. I didn't heat the sanitizer long enough, hence the air bubbles visible inside the legs and the ones I had to remove from the background.

I give up! Three partially-identified beasties.

It's definitely moth season. They're everywhere. A few minutes ago, I even noticed a tiny Indian meal moth trying to crawl into the hinge of my laptop. I found this plume moth in the bathroom sink:

Plume moth, Pterophoridae

Last year, we saw bigger plume moths about; they had tightly rolled-up wings, and slept in a rigid T shape, with 4 legs forming a neat X beneath. The last two legs were hidden.

This one is smaller, more relaxed, leggy, and feathery. I checked BugGuide for an ID, but gave up soon; there are 624 photos there! And too many look alike. I'll have to bother them with my photos, I guess.

The wings of plume moths are split, into two parts (plumes), as here, or three.

Tortricid. Tufted moth, unidentified.

This little critter was resting on the laundry that I had hung out to dry. It's just one cm. long, less than half an inch. These moths wear two or three tufts of feathers on the upper back.

As above, I gave up on the photos on BugGuide, but not until I'd put in an hour squinting at 24,000 photos. I quit when I got to the 100th page and realized that there were still 69 left to go! I am once again amazed at the incredible diversity of our tiny neighbours.

And Jumpy, here, is getting fat on moths:

Jumping spider. High up on a wall, so I could barely see his headlight eyes.

Jumping spiders are easy to recognize. At least, to that level; jumpers. As to the genus and maybe species, that's hard work. BugGuide has 303 pages of them, 24 photos to a page. Seven thousand, two hundred and seventy two photos of jumping spiders!

I think that's a job for another day.

Birthday Moth

It's my birthday today.

And I'm getting my teeth done. Fun, eh?

But, here's a consolation prize, delivered a few hours back: a nice brown moth.


It fluttered like crazy at first, until I followed a hint I think I saw on Bev's blog; I put it in the fridge for an hour. Then it sat nicely for its photograph.

Close-up of "hood" markings.

And I've spent half the night trying to ID it, to no avail. I've submitted it to BugGuide; they are always so helpful.

The feathers on its back: a couple of tufts. Brown, with yellowish tips.

*Update: Bob Patterson at BugGuide says it is probably a Large Yellow Underwing, Noctua pronuba. If so, it's similar, but not identical, to the Yellow Underwings they already have.

Quick work!