At what point did you collect them? Egg, early instar, late instar?

Jeff

Mostly eggs, maybe a few early (very early) instars.

Wow, that is unfortunate. Disease diagnosis in caterpillars can be difficult. What you describe could be a number of things. Do they ooze? Or are they more mummified? Did they exhibit any different behavior before dying? All of these answers help potentially diagnose the disease.
-Elisabeth

Yeah they just die, and eventually kind of "deflate" and turn brown after awhile. It is wierd that ants and such are not even interested, as they are usually all over the cats given an opportunity. I'm just going to leave 'em alone for awhile. Every so often something similar has happened with one species or another, then it goes away. This too will pass.

I just got back from the front porch where I found a red-spotted purple - about ?4th instar? dead in the cage. It had oozed. I was raising three cats, either RSPs or viceroys, on willow in a container in my bathroom, under cooler, 80-degree conditions. They all died during about the ?3rd or 4th instar, they all oozed, and it really stunk. I had been wondering why this could have happened to the willow group, and thought maybe my neighbors put out poison and some got on the willow leaves I brought in? I wash them off, but you never know. The red-spotted purple was on cherry that I got from a tree on the other side of those neighbors.

This has happened occasionally in the past, and the only connecting fact I can think of is that it has happened when there were a lot of one species. It happened one year to a batch of monarchs when I had a lot of monarch cats, one year to a batch of pipevine swallowtails when I had a lot, and now it's happened to the red-spotted purples during a year when red-spotted purples are everywhere. I've brought in a lot to raise myself, but a lot are raising themselves outside. The conditions in my cages are NOT crowded, so I assume it happens before I bring them in.
Anyway, I won't be bringing in any more RSPs. As you said, this has happened before, but it always goes away, isn't a permanent condition.
I know you've released a tremendous number of butterflies this year, so I imagine you've had a lot of several different species.
Of course, I don't know for sure what causes it, the large numbers was just a connecting factor. Maybe one individual gets a disease, and then it gets spread around? 'Don't know.
Sherry

Both bacterial and viral diseases can ooze. A caterpillar dying quickly and turning quickly to mush is characteristic of NPV, a virus. In addition it really stinks. The caterpillars quickly transfer the disease to each other in containers. The disease spreads in the wild from contaminated plant material. An infected caterpillar dies and rain spreads the viral material onto the plant. Eggs laid on the infected plant material become contaminated and the first instars eat the egg shell or plant and become infected. Caterpillars with this disease rarely survive to adulthood. In addition, the virus has been found in flys and parasitoid wasps. So, it may be transmitted from fly poop or when attacked by parasitoids.

Caterpillars that turn brown and sort of mummify are characteristic of a fungal disease. This usually takes a while to happen depending on the fungus. If it is a microsporidia like Nosema or OE, it can take a long time to die.

I have seen one set of caterpillars die from what we think was overspray from a neighboring yard. They vomited their food, started to turn black from the head and died. It was not pretty.

You are both right, when large populations of a species occur, a disease outbreak can happen. It is called epizootic.

If your caterpillars are affected in containers, clean them thoroughly with 10% bleach. There are some world health standards out there on the internet. If I find them I will post them. Oh, and I mean clean the containers not the caterpillars!

Good luck,
Elisabeth

So now one (BST), that had been on a potted rue, outside, alone, made it to the sling. Figured maybe isolation had kept him healthy. But then he turned brown while in the sling and never pupated. ARGH.

Also something I didn't think about till I really started paying attention, but they are not making much frass, and what there is seems rather shriveled and dry. Although they seem to have healthy appetites.

So the other day I picked up three new parsley plants with bunches of eggs and one little cat. They have been outside the entire time, about 15 little cats now. I'm leaving them out there and see what happens. Although the parsley will run out before they all grow up fully so will have to see what happens then. Maybe I should see how their frass production is.

Also the last three GSTs are doing the same thing, several have died and the last ones looked healthy for awhile, but they are not doing a lot of eating and not much frass at all. Especially for almost full-grown GST cats. sigh.

The giants

That really sounds like a microsporidia to me. They almost seem constipated and the frass is as you discribe. The only way to be sure is to send a sample to a pathology lab. There are people who do this work for a fee. However, I doubt you want to go to those lengths. Keep sanitary conditions and don't use plant material that is infected (easier said than done). You may have to wait till the infection burns itself out. Unfortuantely, microsporidias are some of the more difficult ones, especially since you are in Florida. OE is a microsporidian disease and Florida is a hotspot for the disease. I think the cold up north helps control some of it.

Good luck,
Elisabeth

Thanks for all the input. Of course I always bleach containers, etc. but if plants somehow are infected, not sure what to do but just wait it out. It does seem like this happens more often during the hottest weather. The good thing is (knock on wood) so far all the other species are doing fine. Not gonna bring in any more BST or GST for awhile.

Sorry to hear about your disease problems.

Can a person wash leaves in a bleach solution then rinse before offering them? I have a Tiger Swallowtail cat that's oozing. It was half grown when I found it outside so I kept it separate from my other cats. I don't want to bring in contaminated leaves to feed my others but I only have one Tulip tree to gather leaves from.

I've never tried it, but might have to soon. The next batch on the "new" parsley plants are growing fast and seem very healthy, but once those parsleys are all gone, which will not be long...

I've only seen discussions on rinsing milkweed leaves in 10% bleach for Monarchs. I don't know if it's ok for other leaves. Dill and Fennel leaves aren't nearly as thick as milkweed leaves. Maybe someone else will know.

Yes, you can. Some respond better than others. I fill a bathtub with water and put the bleach in there. Then I leave the plant material for 5-10 minutes (I think the WHO standards are 10 minutes). It has to be more than just a rinse off. Then I drain and rinse till I don't smell bleach anymore. Plants are pretty tough. I do enough to put some in vases to keep fresh for another couple feeds so I don't have to do it each time. The key thing is to make sure the leaves are bleach free. Chlorine does evaporate, so leaving the leaves to dry helps too. You can do this with enough material to pack some in plastic bags and store in the refrigerator.

Now, I don't do this with all my material. Too much work. However, if I know there is a problem or am working with something special (Zebra Swallowtails), I will do this. I DO rinse all my materials and then dry them. This may or may not work to rid disease, but it also helps to cut down on any predators that may be lurking.

There are different ratios out there for bleach. The most common being 1/4 cup to a gallon. I don't usually use this amout since I let the materials sit. It is up to you to use what you feel comfortable with.

Good luck
Elisabeth

Well the most recent batch I mentioned is doing well, as far as I can tell. They hatched and have mostly pupated over the last couple of weeks. We will see for sure when/if they eclose.

So does anyone have information on these infections and how long they stay on plant material? I have a few potted rue plants and I don't know if they are safe. Some have not had caterpillars on them in a long time, if ever. But some of the sick ones were on rue that I thought were safe. Maybe as eggs they were already infected, who knows. Rue is really the only food I have for them now that everything else has been killed by heat. Just wondering.

I've had a lot more BST's this year then I have ever had before. I've had 2 problems with some of them. The first is that they seem to stop growing and eating. I had 2 that hatched from eggs about a day apart from several others and they stayed maybe 1st or 2nd instar and no longer ate, just walked around doing nothing while the other grew, ate, etc... My second problem was during pupation. I had some that while shedding their skin for the last time to become a chrysalis, couldn't get the skin off very much and leaked some green fluid. A few did get the skin off all the way, but had parts of them that were "exposed," with green fluid again. I don't know why some had problems like that and others from the same "batch," were perfectly fine.

I've also noticed that when the temperature rises dramatically, there is often an increase in butterfly deaths. I think that there is a definite increase in various bacteria/virus/fungus during these times as it is an opportune time for these little critters to grow. Creepy, to be sure. Bummer but I guess it is a way for nature to keep things in check.

This thread was & is extremely helpful to me-- I'm reading it two years after the last post. I just wanted to say Thank-you to fighting8r for starting it and continuing to give updates, and to bananasinohio (Elizabeth) for sharing her expertise and advice.

I've had a problem with each of the 3 Pipevine Swallowtail cats that I brought inside. Two seemed healthy until time to pupate. One of those purged frass that looked like coffee grounds prior to J'ing and the other one purged brownish liquid in several places in the container prior to J'ing. BOTH did NOT make a harness for pupation, so when they pupated, they ended up on the floor of the container with parts of the chrysalis detached. The 3rd caterpillar seemed very healthy/robust, purged ok, made a harness, and pupated normally and had a very healthy looking chrysalis. 12 days later it eclosed while I was at work--came home to find it struggling because one wing was still stuck inside the chrysalis. I got it out, but it stayed shriveled up. The butterfly was not interested in nectaring. It died the following day.

Now I have 8 Giant STs which I brought inside as eggs. They are eating, but I have this creepy feeling that they're all going to die from whatever the Pipevines had. I bleached the containers and table surfaces and replaced the mosquito-netting I had used to cover the containers with new netting. But I still don't feel very hopeful. It's very discouraging when they get sick and don't make it to adulthood--- you just get this ominous feeling that all subsequent efforts are doomed. Sigh.

Anyway, thank you to all who posted in this thread! Very helpful!

Hi Canny;
I saw your email. I can't respond via email through gardenweb. I will answer your question here but if you want me to email, you will have to include your email address in the next email you send.

First, this year has been terrible. There has been more disease than I can remember. I have lost more caterpillars this year than all the years I have raised caterpillars together. I am hearing similar reports from others. For those of us who had a cool and wet spring, that just sets up conditions for disease. Mostly what I am seeing is fungal, which is what you would expect. With the first batch I lost, I thought I had just lost some to maybe bad hygiene (not cleaning the leaves, keeping the container too moist, etc). However, then I saw a picture of a caterpillar from the field with the exact same fungus. So, like I said, with the weather the way it was this summer, it set up perfect conditions for disease.

The situation you describe sounds like Nosema or another fungal infection. There are many different species of Nosema and they infect many different insects including butterflies. Nosema occurs naturally in the wild and has a life history similar to OE. So, butterflies can make it to the adult stage but be weak. They can also make it to the adult stage and pass it on.

It sounds like you have done all the right things. Sometimes it just happens with a particular group, like your pipevines. I wouldn't worry too much unless you see symptoms in your Giants. Typical symptoms would be, very slow growth, not moving much, eating less than usual. Remember that when shedding, caterpillars can behave similarly with the exception of slow growth. Slow growth is almost always a clue that SOMETHING is going on.

Hope that helps,
Elisabeth

I have had trouble c my some of my BST cats this year. They would just fall to the floor of the enclosure and flounder around. They were immediately removed, but I ended up losing most of my cats this way.
A few would make it though, fortunately, to pupation. Darwinism at work, I guess.
Fortunately, this malady did not seem to affect my Monarch cats in any way.

I know this is an old thread but I have many years of experience raising giant, black and spice bush swallowtails. My real love is in the Monarchs which I raise every year and release. I bring in the eggs immediately and isolate each one on fresh sanitized host plant (rue, spice bush and milkweed—all of it. I hve actually heard of bleaching the eggs with a lot of success, but I have too much going on to begin with . . . If there is sickness of any kind it can be more readily isolated so you may not lose the whole generation. I do not mix generations together in the same cage. I especially isolate the chrysalises to their own cage as they develop—you can relocate if needed. Google it.

I find sickness seems correlated to different generations as the female laying the eggs is infected. I wash my hands more than most doctors during the day, especially between dealing with the different varieties. I bleach surfaces with 1 part bleach to 10 parts water. I have a hand vacuum I vacuum the frass that lands outside the cage on surfaces so that it does not smear. I clean the cages twice a day, and with monarchs sometimes more. The theme here is cleanliness. Regardless, it can be such a crap shoot. I have learned over the years how to spot possible sickness early on. Color and plumpness are the main components as discussed above—unless they die shortly after hatching or early instar stages. Even then, you get better at spotting issues earlier. If they are infected with fungus or a virus, well maybe the next generation will do better. You can only do so much—mother nature usually wins.

With the monarchs, I have gotten kind of anal about their health as I release 120-150 yearly. If there is any indication of weakness upon emerging—I euthanize in a plastic container the freezer. when they cannot seem to fly well, I may take a sample of the scales on their abdomen with scotch tape and take a look under the microscope. If uniform scales you are good to go, if they are a mess, I euthanize them so they do not further pollute the population.

There is so much other stuff I can say here about how I do things it would end up being a book. BTW, Tony Gomez has an excellent book that I have learned a great deal from you can download very cheaply. His blog is exceptional for information.

fnfo from: Farmington Monarch Sanctuary, a registered Monarch Waystation.

Hello! I've been raising Black Swallowtails. 20 are overwintering in their chrysalises. One hatched right before the cold and has been in the 2nd instar stage for a month. A week ago, I brought it into the garage to protect it from the freezes. How I can help it grow or is it sick?

@fsuchristy i responded to your discussion.