Whitey cat

[skates4marty]

Refocusing on the live ones -- I sometimes find these whiteys during heat waves. On his next molt, he began to get his black stripes back.

[Mona Miller]

http://www.evansonart.com/monarchdisease.html
"Granulosis virus: caterpillar’s blood turns opaque. This causes the caterpillar to have a whitish or pale appearance. I mostly see this in young caterpillars which die by the time comes to molt, but I have seen in it older ones like the 4th instar in the C10 photos."

[skates4marty]

In 2006, I found a pale one like the one in the first pic, during a blistering heat wave of near 100 degrees, and e-mailed the experts in the field.

MonarchWatch replied: "This is not uncommon. Temperature plays a roll in the color of the monarch caterpillars. When it is very warm the caterpillars will have little black and as you have experienced almost no black. This is in a effort to reflect the sun. On the other hand when it is cold during the caterpillars development there will be virtually no white on the caterpillar. The dark morph is in an effort to absorb heat from the sun."

Karen Oberhauser replied: "That really is a pale caterpillar! The extreme heat is probably responsible - we've studied the effects of temp on color, and those kept in hot conditions are much lighter."

Last week, when I retrieved this Whitey from outside, we had temps in the mid-90s. Here's a pic after his molt. Since this pic was taken, he has molted again and looks like the other cats.

[Mona Miller]

You had talked about having problems with pupating and caterpillers dropping. I was wondering if this could have anything to do with it.

[Wyvern]

I have yet to have any cats that I collected which were pale in color ever die because of their color.... every now and then one would die because it was infected with fly parasites.. but color had nothing to do with it in those cases.

Mostly it's going to be a temperature thing rather than that granulosus virus. Kinda like reptiles.. dark color absorbs heat when they are cold and need to warm up... light color reflects heat and helps cool off when they are too hot. Cats rely on outside heat sources to control their body temps since they don't produce their own internal heat. I've got areas that I collect where the cats tend to be on the pale side.. but they are areas in full sun and no real shade to protect them so their color helps cool them off. Areas where there is too much shade, cats seem to be darker overall.. color helps warm them up during the periods when they do get a small amount of sun. Areas where they have good sun/shade mix.. they tend to be almost always normal colored... no extreme variance one way or the other.

[sbannister]

Have you ever seen an almost totally black one? I have one that looks like a melanic one - if that exists. He does not appear to be sick, he is evenly dark, not mottled or deformed at all. When he first molted he was translucent and now is more opaque and almost velvety looking. You can still see the stripes, but there is no white on him. He is eating. I have some photos and will try to post them tonight.

[Paul Cherubini]

Black ones are common during the winter outdoors, but I've never heard of anyone seeing them in the summer. Are you rearing indoors in an air conditioned building where the caterpillars are not being exposed to the direct sun?

[sbannister]

I brought him inside yesterday but have been watching him outside, where it is really HOT, for a few days. I decided either he's a really neat mutation or really sick. I want to see how he turns out so he is isolated in his own tank. I will keep everyone posted.

[Mona Miller]

Are you planning to test the adult for OE, if it makes it? I have a dark one, too, but it has a few stripes. It couldn't molt properly and has skin, which I can't get off, wrapped around part of its body. It is still eating and growing. I keep spraying it with a bit of water hoping that will soften the skin.

[sbannister]

Here he is.

Black Monarch Cat

. I will test him for OE if he makes it. He is still eating and has grown after a normal molt. My photo really does not show how pretty he is. I will keep y'all posted.

[Mona Miller]

This is how mine looks. You may need to wash off your milkweed leaves. Looks like there is reside from aphids.

[sbannister]

Yes, those are outside where I took that pic. I don't bring them in like that.

[Mona Miller]

So, the little guy is still outside. Maybe that is best. Is it caged outside or free outside?

"What doesn't kill us makes us stronger."
This quote is originally credited to the powerful philosopher Friedrich Nietzsche.

[Paul Cherubini]

The dark caterpillar looks sick to me - notice the 2 front and rear filaments have a limp rather than erect look to them which is not normal. The caterpillars can take the outdoor heat. It was 96 degrees yesturday in the shade when I took this video and even hotter on the exposed milkweed plant this caterpillar was feasting on: http://www.youtube.com/watch?v=5i-19BCH31Q
And last August I took these videos of caterpillars feeding in the sun at a time in the afternoon when it was 106 in the shade:
http://www.youtube.com/watch?v=fWe6NmkoDFI
http://www.youtube.com/watch?v=FX-QrwEWUmo

[Mona Miller]

The dark caterpillar looks sick to me - notice the 2 front and rear filaments have a limp rather than erect look to them which is not normal. The caterpillars can take the outdoor heat. It was 96 degrees yesturday in the shade when I took this video and even hotter on the exposed milkweed plant this caterpillar was feasting on: http://www.youtube.com/watch?v=5i-19BCH31Q
And last August I took these videos of caterpillars feeding in the sun at a time in the afternoon when it was 106 in the shade:
http://www.youtube.com/watch?v=fWe6NmkoDFI
http://www.youtube.com/watch?v=FX-QrwEWUmo

Don't assume something is sick or going to be crippled until it happens? I take a 'wait and see' attitude. I am still feeding my little guy who is very dark and has skin stuck around its middle. Of course, the caterpillar is isolated from other caterpillars and I wash my hands before and after tending it.

[Mona Miller]

This is Spike a Monarch caterpillar with a bit of skin that didn't come off during its molt. It is dark with a few yellow stripes.



I am spraying it with a little water at least two times a day and feeding it with nice fresh milkweed leaves.

[sbannister]

Actually, Mona, I took that picture outside before I brought him inside. Now he is in his own tank, and is an early 5th instar. He is eating quite a bit. I agree with Mona, Paul, I will wait and see. I have seen a lot of sick ones, but not this summer so far. I know what they look like. I am being optimistic about my black caterpillar. I am naming him Othello.

[skates4marty]

Well... since we're posting photos, here's mine, from last year. Can't remember if he turned into a healthy B.

[Mona Miller]

Don't give up. Spike looked like it was going to go to molt. It went under the papertowel. He didn't make it.

But, don't you give up.

[sbannister]

I am sorry to say that Othello did not shed all of his skin when he j-hooked, so I feel sad but at least I kept him isolated so whatever he had (OE, I assume) did not spread.

[Mona Miller]

I'm sorry to hear that. I've had successes, but I've had failures, too. But, I don't give up hope, until there is no hope.

[Paul Cherubini]

Don't assume something is sick or going to be crippled until it happens?

I said the caterpillar "looks sick to me" and today sbannister confirmed that it was fatally ill.

[Mona Miller]

We know, why don't you rub it in. Oh, you forgot to say "told you so".

Not all the caterpillars that I have seen that looked like that die or are sick. I guess you would have threw it away or frozen it immediately.

[sbannister]

Thank you, Mona. I just wanted to give him a chance becasue he could have been something unique. He may not have even been sick but a genetic mutation that would thrive under different conditions.

[Mona Miller]

I understand. Monarch Watch has some caterpillars that ended up making an orangish pupae. They have a genetic mutation.

There are several mutations, which do produce viable offspring:
http://www.monarchwatch.org/update/2004/1022.html#7
http://www.monarchwatch.org/update/2004 ... _pupa.html

[sbannister]

Thanks, Mona - that was so interesting.

[laurierountree]

I have had several of the dark caterpillars this year. It has been cool and rainy here in Maine. After reading this post I'm thinking it is something wrong with them. During pupation one of them appears to have been trying to throw the shed skin off and was flung about 5 inches. The cremaster remained fixed to the screen but had a thin core of green caterpillar material hanging from it. I didn't see any signs of flies or wasps. What do you think could have caused this?
Another dark one- nearly black with no white and only faint yellow pupated today. It appeared to be healthy and so far no problem. I've been moving caterpillars around according to size. Do you think I could have infected all of the normal cats? There are 23 chrysalids hanging and they've all been mixed together at some time. My newer cats are in Glad containers-thank goodness.

[Mona Miller]

There are other caterpillars in the container. Well, some times another caterpillar will eat a pupa. It could be lack of food or lack of eye sight causing this to happen.

Usually, the dark color is due to cold weather. They get darker so they can absorb more heat.