Caterpillar update, we have a butterfly!

I haven't updated on the caterpillars in a while. I should have at least posted when they pupated over a week ago, but since then they've just been hanging around in chrysalis form, and that's not overly exciting.

Monarch chrysalis 10 days after formation

Then this morning we came downstairs and found that one of them had finally darkened. The dark coloration is actually the monarch's wings, visible through the chrysalis. It occurs the day of or the day before eclosion, so this was an exciting find. We immediately moved him to a shady spot on our deck where we could keep an eye on him and still allow him to be free.

Monarch chrysalis, 12 days after formation, 1 hour before eclosing

When a butterfly first emerges from the chrysalis its wings are not wet, but they are folded and unusable. The butterfly must cling to the discarded shell and pump fluid from its distended abdomen into the veins of its wings to shape and strengthen them. Although it will be able to flit a few feet on wobbly wings only an hour or so after emerging, the full hardening process can take up to six hours before it will be able to fly for any real distance.

And...it's a boy! Male monarch's have two raised, black dots on their hind wings that females do not have. These dots contain the pheremones that males will use to attract females for mating.


Two hours after emerging our little guy flitted to a more sheltered location to finish strengthening. Many people who raise monarchs keep them inside enclosures during this vulnerable time and release them only after they are fully capable of flying.

We didn't have a very large enclosure, and I figured we could keep this guy safe long enough outside, but I didn't count on the thunderstorm that swept through our area just twenty minutes after this photo was taken. Some quick and inventive thinking and we had him safely back inside for the duration of the storm. Three hours later, five hours after eclosion, the sun was back out and beginning to dry the world, so we returned him to the out-of-doors. Twenty minutes later we said goodbye to our first monarch.

Now the bad news. When we started this process we had eight monarch caterpillars. The one that just left is the one we were calling fatso, which makes sense because he was obviously the fastest growing and was ahead of the others. I believe that he left as a strong, healthy adult. Unfortunately, the rest of our brood has struggled. We lost two pupae to tachinid fly parasitism. Another died while forming the chrysalis, which I believe was probably due to OE.

Following the eclosing and lift-off of fatso we have four remaining chrysalises, only one of which looks truly healthy. Two are obviously malformed, and one, which formed the latest and is several days behind the others, is showing worrying signs of either OE or fly parasitism. I continually remind myself that these are natural population controls, and that there is nothing we did to intensify the selection or bring on the troubles. At this point we are merely hoping for the best, and at least we have seen fatso off into the wide, wild, blue yonder.

Added note (6/20/12)
We have now lost three of the four remaining would-be butterflies to OE, and I believe I should have said more about this silent killer. OE is short Ophryocystis elektroscirrha. It is a protozoan parasite that infects only monarchs. OE spores are left on milkweed leaves or eggs by the adults, then consumed by the larva (caterpillar). Once the spores have been eaten the protozoa are released inside the body of the caterpillar where they divide and increase their numbers. During the pupal stage (chrysalis), the protozoa reproduce, further increasing in number, and towards the end of the pupal stage they form spores for external survival on the imago, or butterfly. 

Signs of OE depend on the severity of the infection. Mild infections can be difficult to detect, and it's highly possible that we unknowingly released an infected butterfly into the wild, but severe infections lead to deformations, weakness, or outright death. We lost one caterpillar that simply died while forming its chrysalis, another emerged too weak to hold itself up while inflating its wings, another emerged with wings that were no larger than quarters, and the last was unable to fully eclose. These we euthanized by placing in the freezer, and discarded in plastic bags in the garbage to avoid the spreading of spores.

And a last note, about the tachinid fly. This fly lays its eggs inside the caterpillar or egg. The caterpillar often progresses normally, but dies during the pupal stage when the fly also pupates, and exits the chrysalis as a small brown puparium. The upside to the tachinid fly is that it does not only parasitize monarchs, but many garden pests as well, such as gypsy moths and tent caterpillars.

Caterpillar update

All they do is eat, sleep, and poop. We're cleaning their houses at least twice a day now, and they are going through leaves at an incredible rate. Their gluttony has lead to a major size increase, and we have actually watched a few of them molt. I think the pupating stage draws nigh.

I am concerned that some of them are not as "normal" as they should be. In particular their feelers seem to lack symmetry, and I've read both that this could be due to injury from a crowded environment (as they've gotten bigger we have separated them into more tubs), and that it is a sign of OE, the infection that ultimately kills, often during eclosing. If it's OE we are in for a really heartbreaking end, but I keep telling myself it's possible I'm just over-worrying. We are keeping our fingers crossed.

(Here you see them still four to a tub, but we now have them as two to a tub)

Remember when they were oh so tiny???

Monarch caterpillars

Having seen the first monarch in our butterfly garden a while ago, we went out in search of caterpillars this afternoon. We were well rewarded.

After careful searching we found eight cats and brought them in. Why did we bring them all inside? Of course one or two would do for Calvin to observe, but monarchs cats are prone to a high fatality rate in the wild. Wasps, spiders, and flies are predators or parasites, and they are susceptible to a variety of fungal and other infections. Most of these are natural killers (although many pesticides are culprits as well) and as with all wild animals, this is a natural form of population control. But the flip side of the coin is that monarchs are also threatened in other, not so natural ways, in their adult form, and the more cats we can bring to butterfly stage the better. So we brought them in to see if can help them get there safely.

Number 8 is the tiniest, and number 1 we're already calling fatso. Unfortunately, even though we now have them safely away from natural predators, they may still be infected by bacterial or fungal infections and we may not see them all reach the pupal stage. I've read many horror stories and I'm already concerned about one of our little guys, but all we can do is our best.

On the recommendation of a helpful friend, we are keeping them in Glad reusable containers (BPA free!) right now. I line the bottom with moist paper towel to help keep the leaves fresh. At least once daily we prepare a second set of containers and use a soft paint brush to transfer them to the clean home, then disinfect the used container with bleach wipes and wash it to prepare it for the next change. The moist towels keep the leaves fresh longer (keeping the lid on, punched with tack holes, helps with this also), and the bleach is the only thing that will kill some of the threats.

Wish us luck! We'll keep you posted.

Empty chrysalis syndrome

Our black swallowtails finally emerged and left. Having read that they remained as chryslids for only 8-10 days we had come to believe that they were planning to winter over with us, since they had gone into that state while we were still up at Walloon, 14, 15, and 18 days ago. We were surprised and excited, then, to find one of hte shells empty on Sunday afternoon. Having missed the take off of Larry, our first caterpillar turned black swallowtail, we were determined to keep a closer eye on Curly Parsley and Moe so as not to miss the great show. to give them more room we had tied their smaller sticks to longer ones and propped them in an open (never used) bird feeder on our deck table.

This morning we were finally rewarded. Right after eclosing the butterfly has a body distended with fluid and wings folded tightly against the body. They then pump the fluid out of their abdomen and into the veins of their wings to spread them open. These two eclosed probably 4-5 minutes apart, although we missed Moe (on the right) emerging. This picture was taken at 8:48am.

Just four minutes later at 8:52 Curley Parsley (on the left) has significantly altered his appearance. The chrysalis is still there on the stick. Notice that it is no longer dark in color now that the black butterfly is out.

A closer look at Moe so you can see the veins running through her wings. Curly Parsley and Moe were both females, a specific that can be determined by the spot formation on their wings—big yellow spots on the male, smaller yellow spots on the female.

Here is Moe stretching out her proboscis, making sure she's ready to get nectar from the plants she finds.

Stretching and sunning. This was right before Moe took off. Curly Parsley (on the right here) wasn't that far behind time wise, but she stuck around for another 30 minutes.

This is pobably best chance we've ever had, and probably will ever have, to take such a close look at a butterfly.

And just two final shots of Curly Parsley before she took off to look for nectar plants and a mate. Good luck Curly.

Awesome.

Rearing Black Swallowtails

Two weeks or so ago I clipped parsley from the overgrown plants on our deck and stuck the bouquet in a glass of water, hoping to find use for it over time (the parsley has been very happy this year for sure). Then, on Monday of this week, I decided that we'd gotten as much use out of it as we were going to and went to throw out the remaining stalks. Imagine my surprise at finding a very fat bright green and yellow caterpillar perched right on top of my parsley in my cup in my kitchen. He must have come in on the large bunch nearly two weeks ago and has been munching away ever since (I must say, the bunch did seem significantly smaller, but I hadn't paid much attention).

At his current size and appetite we decided that replacing him on the already pared plants outside would be the end of our parsley crop for the year, and in fact a quick check of the outdoor plants revealed his two brothers or sisters on the now much-munched outdoor plants. Not willing to give up my plants or the learning opportunity waiting to be grasped, we brought all three little buggers inside and made them happy with clipped parsley (organic from the store) and sticks inside large wide mouth Ball canning jars. They could have picked better timing, though—looks like they will have to go on vacation with us next week.

Shall we name them Larry, Curly Parsley, and Moe?

The orange horns are a stinky warning to those who might bug him, but we bugged him anyway and brought him inside. The other two were far more mellow about using the horns, but this guy was feisty.

Here are two of the cats, each in a different phase; the one on the left is much bigger and greener and is in the final caterpillar stage while the one on the right will molt one more time.

Fascinating.

We'll keep you posted on their progress.