What's going on?

[ValikinsMouseMonarch]

Hi, I recently started trying to raise monarch caterpillars in my home. I followed all the directions I have come by, including those of my boyfriend's entemology professor who told him to give them a tiny drop of water every now and again. And yet, after about a 2 week period, all but one of 16 caterpillars have died. The first 3 I know died from some sort of bacteria, but why would the rest die? We changed everything in that cage, all of them were separated into two containers to prevent cross contamination, and now we only have one. We've tried changing the milkweed type, cleaning the leaves exceptionally well, and they still died. Anyone know what could be going on?

We bought our caterpillars with a breeding kit. Was that what we did wrong?

Thanks for your help!

Valerie

[monarchmama]

Valikins,

What symptoms/behavior are they displaying and at what age/instar are you losing them? Without knowing that it is sorta hard to tell what is going on.

[ValikinsMouseMonarch]

since this is the first time I've tried raising caterpillars, I have no clue what instar they are. The first few were pretty tiny still (no more than 1/2 an inch) but I know those were due to bacteria. Recently, larger caterpillars (about 1.5 inches) died for apparently no reason. One day they were moving around, the next they looked deflated (not like bacteria deflated, but like they had died and dried out some already). I completely cleaned the cage (including removing all leaves and replacing with fresh leaves) and the next day two more died the same way. So far we have one left that seems to be ok, but I fear it isn't going to make it to chrysalis because of the others.

Edit: The last few seemed to just stop eating. The leaves all came from the same plant, so I dunno why they stopped.

[monarchmama]

Sorry about that. Instars are the five stages of development a caterpillar goes through.

Few more questions for you:

How do you know that the first few died from bacteria?

What type of milkweed are you feeding them and where did you get it? Is there any chance that it could have pesticides on it?

Are you keeping them indoors or outdoors? in the sun or in the shade?

[ValikinsMouseMonarch]

I know the first few were from a bacteria because of the way they died. They seemed to have kind of suddenly turned from normal colors to another icky color and stopped moving alltogether, not to mention died.

Not sure on the type of milkweed. It's some that came with them. Also I got some from Monarch Watch themselves via their website, and the leaves appear the exact same.

The other milkweed we've tried I have no clue what it is, since it came from a field that my boyfriend's professor suggested to get it from. Other bugs seem to be living on it pretty well, so there' s no pesticides.

We were keeping them indoors in one of those critter keepers (a medium size one) per cup of caterpillars (average was about 6 each cup) and feeding them daily or every other day a few leaves of milkweed.

[Farfalla]

It could be so many things,Mouse.
Stress from shipping, virus, protozoa,parasites.
It is my experience that a really, really dry environment is necessary for healthy caterpillars. They get all the moisture they need from the milkweed leaves.So I question the advice you were given about giving them a drop of water. I hate to disagree with an entomology professor
( I am only a preschool teacher.lol) But maybe one of the Monarch gurus here can clarify this.

[monarchmama]

As Farfalla said, it could be so many things. Sometimes it is a matter of trial and error, but can be heartbreaking and discouraging when you first start out.

Something did come to mind as I reread your postings in an effort to figure out what might be going on.

Several years ago, in my search for milkweed, in the same place I harvested common milkweed, I came across a plant that looks similiar to swamp milkweed and has milky sap when you break a stem or leaf. Thinking I had come across another form of milkweed just as I was running low on common milkweed I decided to give it a try. To my chagrin, the cats died after a few days, so I stopped using it. Just recently I came across this plant again and finally was able to identify it.

It is called Dogbane or Indian Hemp (Apocynum cannabinum) and is considered poisonous. If ingested it may cause cardiac arrest, as it contains resins and cardiac glycosides. I am not sure if a caterpillar can have cardiac arrest or not, but do know that it did kill a few of my little guys before I realized it wasn't good for them. The type that grows here in PA and NY looks very similar to young swamp milkweed. Especially when it first comes up and hasn't branched out yet. One clue that helps me identify it that it has red stems, and that it has a small cluster of droopy white bell shaped flowers instead of large upright flower cluster found on most types of milkweed.

Here is link with two pictures if you would like to check it out.

http://www.ces.ncsu.edu/depts/hort/cons ... pocyca.htm

Hope this helps

[Farfalla]

Wow! You learn something new everyday!
Thanks for posting that Monarchmomma!
Bet you will save a lot of caterpillars!
I am just starting to run a bit low on my garden supply and need to go into the field to feed my hungry crew.......And I just know I might have made that mistake,too!!!

[ValikinsMouseMonarch]

Thanks guys. I know the milkweed is definitely milkweed because it has the same seed pod as milkweed. I don't think dogbane or whatever has the same kind of seed pod. who knows?

anyway, the last caterpillar seems to be doing ok. I just gave it a couple of small fresh leaves (thoroughly washed) and he seems to be doing good.

Thanks for the help you guys. Any advice is alway sappreciated.

[MILW]

Unfortunately, it appears that the Monarchs are susceptible to a lot of diseases and parasites. Seems like a lot of people are having troubles this summer, I wonder if it is partly due to having a large population out there to support epizootics?

I've lost a lot of cats because they are failing to molt completely- I'm not sure but suspect the containers I've had them in were too damp. I'll be trying harder to keep them dry and clean for the remainder of the summer!

good luck! -Scott

[ValikinsMouseMonarch]

Can a caterpillar actually FAIL to MOLT from being too moist??

[MILW]

Well, the observation is: cats failed to molt (head capsules didn't come off, so they didn't try to crawl out of the old skin) AND container was more moist than usual- condensation on lid and sides. It's just a correlation, not necessarily causation.

I haven't tried to repeat the experiment, but haven't had trouble since keeping the containers dryer... The other reason for dryer conditions is that moisture helps the growth of bacteria and fungi, both of which can cause trouble for the cats.

cheers- Scott

[ValikinsMouseMonarch]

Update: Last one died today. No symptoms other than laying on the bottom of the cage on its side.

Guess I'll have to try again another time.