My Egg Distaster, Any Advice Is Appreciated

[Gwynne]

I wrote about gathering 15 eggs on Monday. I ended up putting them in 4 ziplock bags with moist paper towels. One egg was dark, so I kept him alone in case he was either sick or ready to hatch The other 14 I spread between 3 bags. I had cut up the leaves in two of the bags and left them intact in the others. This was because of space limitations. If I had more room, I would have given them all their own bag. On Wednesday, with eggs hatching, I realized that the ones on tiny leaves would need more room so I went out to get more leaves. I ended up finding four more baby caterpillars. Most looked under a day old, one looked about a day or two old. I took them back to the house as there were many predators in the patch of milkweed. This is the patch where I have found all my caterpillars. It was hard finding nice leaves though.

I ended up changing most of the bags, even though I didnt want to disturb the caterpillars. I put a whole leaf in the bags and put 3 or 4 caterpillars on their little pieces of leaves on top of the leaf. I think I kept the eggs separate. With the addition of the new caterpillars, I must have had somewhere between 11 and 13 caterpillars. Every day when I would check on them, there would be less and less caterpillars! I dont think they ate each other. I think what happened was that they would crawl off the leaf into the damp paper towels and become stuck there. That is what looks like happened when I took the paper towels out. It looked more like dead caterpillars than excrement on the papertowels, though I could be mistaken. I dont know if this happened because I disturbed them checking on them or the paper towels were too moist or if not all survive even in the best of condistion, which I certainly dont have the knowledge to provide!

I took the six survivers today and lined a clear dollar store box with moist paper towels and put them on five leaves. I didnt want to touch the caterpillars so I ended up cutting out the pieces of leaves they were on and putting them upside down on top of the leaves. I put them upside down because I noticed they like to be out of sight. Interestingly enough, four of the survivors are the four I found outside, already hatched. One of the six caterpillars is darker than all the others. A mutant perhaps? Since I didnt notice that till I had them all arranged, I dont know if he was one that I found outside.

I have no lid on the box because my friend cant find his drill. I assume that is how to get holes in the lid? If there is another way, I would love to know. I also bought small containers at the dollar store, but couldnt punch holes in the lid with a fork. I dont want huge holes either.

Sorry this is so long, but I am trying to describe accurately the conditions in case any one has imput to offer. Their chancs might be better in the wild!

For people who keep them in ziplock bags, how big do they have to be before they can be moved? There was a lot of excrement all over the paper towels. When I had the bigger caterpillars, I cleaned the cages twice a day. With the babies, I really didnt clean them other than when I got the fresh leaves after two days. That was because I didnt know if they were too little to transfer to fresh leaves. The excrement probably didnt help matters either.

So if anyone can tell me how often to change the paper towels and ziplock bags, that would be helpful. Or do I just leave them there and not touch them for several days?

On a happier note, caterpillar number five emerged yesterday while I was at work. It was a beautiful boy. It was obvious he wanted to be on his way so I released him last night.

[Jim]

Actually, you don't want moist paper towels in monarch rearing chambers - especially if there is not much airflow. Too much humidity will only provide a good environment for growing molds and fungus (and may drown tiny cats). Paper towels in the chambers are intended to absorb humidity and should be changed out everyday or every other day (depending on caterpillar size), along with the milkweed leaves. You can vary the size/amount of leaves so that the cats finish most of their food by the time the next changing comes along. You can simply add the new leaves and the cats will transfer themselves (then you can remove old leaf material if necessary).

As far as making holes in plastic container lids is concerned, a drill will do fine but you can also us anything sharp to poke holes - an awl, a small screwdriver, a skewer, a nail, etc. The important thing is to provide enough holes to allow decent airflow so that condensation doesn't build up inside the container. Also, be sure to keep the containers out of direct sunlight for the same reason.

Good Luck!

[Gwynne]

Jim, what about when you are dealing with eggs? How do you keep the milkweed alive long enough for the eggs to hatch?

I have seven caterpillers at this point. There is a tiny one, like a runt. He moves around and eats, but doesnt get any bigger. He doesnt look sickly and if I found him, I would say he was in decent shape. But knowing he is at least three days old, if not older, I am wondering why he isnt growing. The other six are close to half an inch long. Two of them are climbing on the paper towels that go partway up the side of the aquarium. Or rather, they are just staying there. I am not touching them this time!

[Jim]

Jim, what about when you are dealing with eggs? How do you keep the milkweed alive long enough for the eggs to hatch?

Well, most of our cats emerge on our special oviposition plants that come out of our mating cages, but the leaves that fall off, shrivel up and get a little crispy don't seem to have an effect on the hatching eggs. If kept warm, the eggs will hatch in 3 or 4 days and if you find the eggs in the wild they are likely a day or two old already so they really don't spend much time on the dead/dying leaves. When you start to see the black head capsule through the eggshell you know the cat will be eating its way out soon - you can provide a fresh leaf at that point.

I would recommend isolating your runt caterpillar - something isn't quite right and you don't want to expose the other cats to possible disease...

[Gwynne]

Thanks for your advice. Probably to late on the isolating the runt caterpillar, but I will do so now.

[ORANGEMUSTANG]

If your plasitc lid is too thick to push a fork through, try heating up a fork or knife over the stove and melting holes.

[monarchmama]

Gwynne: I am not sure if I miswrote on the other thread before or not, but I didn't use paper towel in my ziplock bags last year, just soaked the new leaves in water and shook them off before I put them in bag with larvae. Tiny larvae can drown in very little water. I did use tiny pieces (1/4 x 1/2 inches) of moist paper towel with some eggs I clipped from leaves this year, but removed once egg hatched and I put new food in.
The other problem I found with paper towells is that some of the cheaper brands have a high formaldahyd content that could prove deadly to these tiny guys. Before you use any paper towels in a raising tank take a deep whiff of the paper towell roll and if it has a strong chemical smell to it , don't use it.

White paper napkins make a decent cage liner and usually don't have a chemical smell or sizing added to them, and should be safer to use, but as Jim said they are there to absorb moisture and catch droppings, and should not be wet, and should be changed often.

If your plastic containers or jars have lip edge on them you can tie or rubber band thin fabric or muslin around them. The mesh is fine enough that the tiny guys cannot escape (you would be surprised at how far and how fast these little guys can crawl when they get a mind to!)

With heavy plastic bins or tubs I use a woodburner or soldering iron to melt holes in the lids. A cooking fork or piece of coat hanger heated in flame of gas stove also works well to burn holes in soft plastic.


Hope that helps.