Sometimes a person has to do his/her own research. Way to go, Sherry. Thanks for posting the photo. We sometimes get red admirals flying around here in the summer, but I have never seen the caterpillar before.

They're one of my favorite butterflies, Eric - their colors are so beautiful!
I'll go look for some of those cocoon things tomorrow.
Sherry

I've also had lots of the white cocoons on the Red Admiral larvae. Here's a picture of what emerges. It was one inch long.

http://www.tomterrific.com/temp/Red%20Admiral-wasp-emerged-1eightinch.jpg

Here is a link that might be useful: {{gwi:472659}}

Here's the Red Admiral Killer. 1" long.

{{gwi:472663}}

Well, that figures, Butterflyman! Thanks for the info and the picture.
These wasps may explain why, although red admirals are regulars here, I never see more than a few at any time, their numbers are never high. I've read the same thing in several of my butterfly books. If all those little cats had lived, I'd have V. atalanta flying everywhere!
Thanks for the picture and the info.
Sherry

I've been dealing with parasitic wasps and red admirals since the early '70s. They have a boom/bust relationship. If the wasps seem like they are killing all the RA cats this year, you should have RAs out the wazoo in 2011.

I have yet to see a RA this year. 2005 and 2006 were bad years. 2007 was great. 2008 started well but the predators all but eliminated the 2nd brood. I'm not holding my breath that 2009 will turn out well here.

KC

Thanks for the info, KC and Butterflyman! I've been reading everything I can find on predatory wasps. I haven't read anything that says the wasps inject their eggs into the butterfly eggs, but I did read that some put an egg into very tiny hatchlings - after they've eviscerated their host, you can find the cocoon next to the remains of the host. This fits the description of what is happening here. The only practical way of saving each future RA would be to monitor my false nettles constantly for eggs and take them into a cage right then, before they hatch. I've got false nettles in three main areas, plus a few in my garden - I found my first hatchling on a plant in the garden yesterday. One new area has yet to be used by the red admirals.
I found three late instar cats all wrapped up in the typical messy wad of several leaves that they make - all the caged cats have done that to their leaves as well. I decided to leave these three outside - their nests looked very tight, so I'll just wait and bring in the chrysalids if I can find them.
Sherry

Late this afternoon I checked the biggest group of false nettles and found some tiny caterpillars. I brought in nine, and I'll look some more tomorrow. I've been watching for red admirals in the vicinity of the nettles, but never saw any, so this was a surprise!
I sure hope these haven't been parasitized! I'll even look for eggs tomorrow.
Sherry

I've been cutting off every stem that has a leaf that has any evidence of a red admiral caterpillar being there. Many of the cats I've brought in have been parasitized, making the dreaded tiny white cocoons with the dead RA cat next to it. I pull the cocoons with my fingernails until they're in at least two pieces. I figure every cocoon I destroy is one less parasitic wasp that'll breed in the future and make more of them. Quite a few of them aren't parasitized, and by bringing them in, at least they can't be killed by other predators.
Red admirals are variable caterpillars - this last group has a lot of red in it. I caught this one making a new nest -
{{gwi:472666}}
Sherry

What you are describing is very typical of ichneumon wasps. They tend to have one larva that exits and pupates. The cocoon can even have very pretty patterns (see http://bugguide.net/node/view/21674/bgimage ). There are wasps that lay eggs inside eggs. These are the trichogramas typically. However, they usually kill the developing eggs and a fully grown wasp emerges.

KC is right about the boom-bust cycle. We are seeing Red Admirals down here in the South Dayton area (just wait KC they are coming to Columbus soon). Last year though, I swear I saw two all summer long. I caught a nice, hopefully, female for the house just last night. She was hanging around the hops vine and nettle outside the house so hopefully she will lay some eggs for us.

I am afraid the only thing you can do is to net the plants as soon as mom lays the eggs. As soon as they hatch and start munching the wasps find them. The wasps locate the caterpillar by using the chemical clues around the plant. Both volatiles that the plant produces and that of the caterpillar. It has been well studied in the Manduca sexta. The tobacco plant even has evolved to produce different chemical responses to the types of damage it receives. If it is a caterpillar munching on it, the plant releases chemicals that alert wasps to the presence of the caterpillar.

Cheers,
Elisabeth

Thanks for posting the pics MissSherry. I especially like the one with the nest, so I can see what they look like.

Hope you get lots of RAS to release soon; they must be extra-stunning when freshly eclosed!

I would not even recognize that as an RA cat. Looks nothing like the black ones I get.

Yesterday, I got 4 RA cats, smashed one parasite pupa and zapped 5 paper wasps. This morning, I got 2 more RA cats and got to see a paper wasp get an RA cat before I could get the cat :(

KC

Thanks for the info Elisabeth!
Yes, Bernergrrl, they're gorgeous when newly released, one of my top three butterflies!
I know just what you mean, KC. I've got one unhatched egg that I got immediately after the female laid the egg, but I don't know how I could get every egg right after it gets oviposited. It appears that they lay them one or a few at the time, just like my female gulf frit is doing. This means I'd have to stay by the nettles all day long - even then I could miss some, because I've got three big groups of them, far apart from each other.
I've had cats that were black and yellow, and some black and red - these are redder than any yet, but then they're still young and may "blacken" up!
Sherry

I wonder if you could somehow "cage" the female. Either catch her and put her in a cage with potted nettle (yikes! I'd hate to pot up nettle) or some other fashion. Different butterflies have different techniques. I think Jaret Daniels was using Dixie cups and a sprig of host plant for momma miami blues to lay on. Now RAs are bigger but...maybe a big gulp cup? I wonder if anyone has bred them in captivity. I will ask around.
-Elisabeth

Thanks for the interest, Elisabeth!
The oldest of the cats from this group was wandering around like maybe it was looking for a place to pupate. I brought it some wet, fresh leaves in case it just wanted better food, and I was able to get its picture.
This must be what the the little red one in the above picture will look like later -
{{gwi:472669}}
Sherry

I like the color variation. Mine have always been black.

Sandy

I saw one of these beauties yesterday! Quite a sight; I don't think I've seen one for a couple of years, and the last one was pretty tattered. The one from yesterday was very spruce and handsome.

I hope that it finds (if female) the hops vine I planted. I also have seedling clearweed (Pilia pumilia) that may be a host plant too.

The second batch have been emerging lately, three of them today! I usually don't have enough of them at any one time for that many to emerge in one day. One of them must not have been quite ready when I released them, because it flew to the wild black cherry tree by the porch and hung out for a while before it flew off -
{{gwi:472671}}
Sherry

Very pretty!

Link to other big thread on Red Admirals.

Here is a link that might be useful: Red Admiral Cats!