Could Raising Captive Monarchs Mess Up Migration?

A late-season male Monarch butterfly nectars on my New York Asters

As you may have heard, alarming new research about raising Monarch butterflies was published recently, by Ayşe Tenger-Trolander, Wei Lu, Michelle Noyes, and Marcus R. Kronforst. Their study found that indoor-reared fifth-generation Monarch butterflies did not display southward flight in tests, which means they wouldn't migrate properly. Uh-oh!

I haven't been able to access the entire article yet, just the abstract linked above, and a write-up in Science. But even those limited sources give me concern about my techniques in raising Monarchs. The researchers raised both commercially-bred monarch caterpillars and wild-caught. Although they used the caterpillar generation that's supposed to migrate, both groups  had neither the elongated wings of migratory individuals, nor showed predominantly southward flight under test conditions. (They attached the mature butterflies to poles in the experiment, so they could observe which directions each butterfly would head. Previous research has shown that in these conditions, migratory monarchs reliably try to fly southward.) The scientists even raised some wild individuals outdoors until the point of pupation, and found that if those individuals eclosed indoors, they too seemed to have lost the tendency to migrate!

Two of my Monarch chrysalids last year, raised indoors & then released after eclosing.

Not unexpectedly, this has thrown the butterfly-raising community into a bit of a tither. Are we actually exacerbating the threats to monarch migration as we try to help? When our efforts include raising the caterpillars indoors, especially the migratory generation, it looks like maybe so.

From what I'm seeing on various email groups, Twitter, and Facebook, many caterpillar hobbyists and citizen scientists are distraught. Should we change our habits and maybe abandon the hobby of raising monarchs?

Honestly, I've already been somewhat concerned about my butterfly raising. This isn't the first study to indicate we might be doing more harm than good, for one thing. I had thought, though, that the main problem was using captive-bred caterpillars, like classrooms might when they mail-order caterpillars from who knows where in order to have them on time for the lesson plan. Since I only raise wild-caught individuals (whether starting as egg or already-hatched caterpillar), I hoped I wasn't doing too much damage.

But another effect of captive-raising caterpillars can be to allow weak genes to survive and get passed along. Since I'm protecting the caterpillars from natural stresses, a trait that would have made an individual less likely to survive isn't actually a problem, and may end up expressed in the next generation too. Especially if I raise every monarch caterpillar I can find, I might still be making my local population less fit. Now this new research just adds more support to reconsidering my actions.

This Monarch caterpillar lived its entire life outdoors at Brookside Gardens, where I found it getting ready to pupate.

I can't speak to what anybody else will or should do, of course, but here are ways I'm planning to change my caterpillar husbandry:

• In general, I will collect and rear no more than 50% of the eggs and/or caterpillars that I find in my garden, of each species. The rest I'll leave wild and unbothered, to fend for themselves. (This also means I'm not reducing the amount of available food for hungry birds!)
• For monarchs in particular, I will rear no more than two caterpillars per generation for the first four generations each year.
• Once the migratory generation's eggs are laid, starting around August in my area, I won't raise any monarchs. 

I also considered trying to create an outdoor setup for raising monarch caterpillars, rather than keeping them in my office indoors. That will take quite a bit more planning, however, so stay tuned.

Another idea was to raise monarchs indoors until they look ready to pupate. Then I could move them outside while they pupate and later eclose. Although I'm not sure exactly what the pupa get from being outdoors, the new research does indicate it's a crucial factor in triggering migration: "In fact, merely eclosing indoors after an otherwise complete lifecycle outdoors was enough to disrupt southern orientation."

I'm not changing how I raise Black Swallowtail caterpillars, or other non-migratory species, as much as I'm changing my treatment of monarchs. I'm definitely reducing how many I raise, going by the 50% rule above. Also, if I find a single egg or caterpillar on any day, I won't bring that in at all. I know I still might be changing something essential in these butterflies by raising them in the protected environment of my office. However, I do call them "pets" sometimes because I know they may not be the same as totally wild individuals. I guess they're kind of half-wild; I do release them as soon as they eclose. I always hope they make my local population larger, going on to mate and lay more eggs that lead to more caterpillars. This summer I'll keep thinking about whether I feel comfortable bringing them inside any more.

As much as I love watching the caterpillars up close, am I being selfish by bringing them inside?

Do you raise butterflies indoors, or have you ever? What do you think about this new research? I'd love to hear your thoughts, whether you plan to stop raising butterflies at all or keep on caring for them like you always have.  Perhaps you even have a totally different method of raising caterpillars than I do. Whatever the case, please leave a comment below to keep the conversation going!

Those Sneaky Spicebush Swallowtails

Not a bird dropping, but a sneaky Spicebush Swallowtail caterpillar, exposed!

Recently, it’s been taking me a long time to get home from work most evenings. It’s not that I’m running into a lot of traffic or other typical delays. No, it’s that the path I take back to my car is lined with native Spicebushes. This summer I finally figured out how to ID them when they’re not in flower, plus I learned the sneaky trick that Spicebush Swallowtail caterpillars use to avoid being spotted. So of course I have to check every spicebush, every branch I can reach, nearly every leaf, on my way back to the car. I’m looking for folded-over leaves, or just small sections of leaf that have been folded longitudinally to make a shelter for (I hope) a tiny Spicebush Swallowtail Caterpillar. It’s a bit like a treasure hunt every evening!

One of the many Spicebushes (Lindera benzoin) near where I work in Maryland.The ones along this trail are about six feet or so tall and wide, although they can get twice that size. Ovate leaves are alternate, and lots of oval berries sprout along the branches.

Here's a closer view of a Spicebush branch, showing the many berries. They're green right now, and turn red when ripe.

 

A Gift With A Bonus

This all started with a gift from my boss: a small potted Spicebush that came with a bonus: a caterpillar already in residence. My boss had bought several bushes for his yard and ended up not needing them all. Most had already been visited by breeding Spicebush Swallowtails, who depend on  spicebush as their larval host plant. Knowing that I love raising caterpillars, he offered one of the extra bushes to me.

A folded leaf containing my new Spicebush Swallowtail caterpillar. The caterpillar makes this shelter by laying silk across the leaf, so the sides will close up as the silk dries out and shrinks. Pretty crafty!

I brought the bush and caterpillar home, and over the next few weeks raised the caterpillar to a butterfly. By the time I released the adult butterfly, I was hooked on my second caterpillar species. I was having so much fun, I forgot to even take photos as the caterpillar grew up.

Gleefully releasing my first-ever Spicebush Swallowtail. The branch inside the cage is spicebush that I'd hoped would be a pupation site, but of course my caterpillar decided to adhere to one of the cage walls instead. It worked out though!

I’m currently in between generations of Black Swallowtails, so my caterpillar craving has gone unanswered for a while. It seemed like Spicebush Swallowtails might make a good supplement to the Black Swallowtails.

Now everywhere I go I’m checking spicebushes for the tell-tale leaf shelters. Spicebushes are native and grow throughout the eastern United States, so I'm seeing a lot of them anywhere I hike. I did actually find one tiny caterpillar while I was visiting my mom in Ohio a few weeks ago. (I was too excited to remember to photograph it, though!)

           

Extra Defenses

I mentioned that the caterpillars hide by rolling up in leaf shelters, which is cool enough. What’s even more amazing to me is that they only come out to eat at night. Before this summer I had no idea there were nocturnal caterpillars! While I was raising the one I got from my boss, after sunset I’d sneak into my now-dark home office and flip on the light to surprise the caterpillar and catch a glimpse of it. As I mentioned, though, I neglected to photograph the caterpillar as it changed over the days.

I peeled open the leaf shelter to photograph the caterpillar when I first received it. Surely I'm not the only one who thinks the newly forming eyespots are kind of adorable!

The caterpillars also have special disguises just in case they get seen: the early instars are bird-dropping mimics, like many other swallowtail species. Later instars have these really cool fake eyes that make them look like tiny fierce snakes. They hide inside their leaf shelter with their head pointing up so the snake eyes will look back at any predator smart or curious enough to peek inside the shelter. Yikes! As you see in the above image, my caterpillar was a middle instar that had both the bird poop camouflage and fake eyes starting to show, complete with false light reflection. Pretty cool.

Since I didn't photograph my caterpillar in later instars, here's one taken by Hagerty Ryan, U.S. Fish & Wildlife Service [Public Domain], via Wikimedia Commons. Those eyespots have gotten much more prominent!

I Have Hope           

So I’ve spent a lot of time over the past few weeks looking for these awesome little critters. But I haven’t found any others besides the one in Ohio. I have found many other tiny things hiding in similar leaf shelters, however: mortally offended spiders as well as a terrified tree cricket, for example. I’ve also found lots of empty leaf shelters whose caterpillars have long since moved on, and I’ve seen tons of nibbled leaves that give me hope. I’m sure not all the nibbling is done by Spicebush Swallowtail caterpillars, of course, some is also done by beetles and other hungry insects. But I have been seeing a lot of adult Spicebush Swallowtails flying around Brookside Gardens lately, nectaring on the many flowers in bloom. So there must be caterpillars eventually, right?

Adult Spicebush Swallowtail nectaring on Cardinal Flower (Lobelia) at Brookside Gardens, in Wheaton, MD.

For that matter, there must also be eggs at some point. The Spicebush Swallowtail’s eggs are usually laid on the underside of spicebush leaves, and are very pale so they blend in. Yet another piece of evidence of the sneakiness of  these canny creatures! Honestly, I don’t even bother to look for eggs on the spicebushes, they are so well camouflaged I feel like it would be hopeless unless I actually get to watch the butterfly oviposit.

Three tiny white eggs on the pale underside of Spicebush leaves. Photographed at the Wings of Fancy Live Butterfly and Caterpillar Exhibit at Brookside Gardens, Wheaton MD (see below for exhibit details). The red ribbon is added by staff to call attention to points of interest like small caterpillars and eggs. Look to the right of the ribbon to find the eggs, if you don't see them at first!

 

Still Searching

For now I’ll just keep looking for the hidden Spicebush Swallowtail caterpillars, and keep coming home late for dinner. It’s a good thing I’m using my slow cooker a lot this summer, I’ve already started the meal eight hours ago and I know it will be done whenever I get home.

Have you ever spotted Spicebush Swallowtail caterpillars in the wild? Leave a note in the comments if you have! If I manage to find another one I’ll remember to take a picture this time to share with you all. But even if I never find another caterpillar, I’m still enjoying the daily treasure hunt. It’s a very peaceful, mellow way to wind down after work. I hope you too have a chance to see the tiny hidden things in nature, no matter how sneakily they might be disguised.

If You Want To Visit Wings of Fancy

If you're interested in checking out the Wings of Fancy exhibit for yourself, it runs through October 25, 2015. Normally it's May through mid September, but the schedule is different this year. The exhibit is at Brookside Gardens in Wheaton, MD, and is open seven days a week from 10:00 am to 4:00 pm. Tickets are $8 per adult and $5 per child age 3-12. You can purchase your tickets at the gift shop in the Conservatory. Please keep in mind that parking may be limited at the moment; consult the Brookside Gardens web page (www.brooksidegardens.org) for any updates or for suggested parking alternatives. The street address for the Conservatory and the exhibit is 1500 Glenallan Avenue, Wheaton, MD 20902.

I personally think one of the best things about the exhibit is the Caterpillar House, where we have various larval hostplants with eggs and/or caterpillars on them, as well as a special container for chrysalises once the caterpillars get to the wandering stage. The species in the Caterpillar house change periodically, but are always North American native species. It's so cool to see the caterpillars up close, plus the display also has photos of each caterpillar species in adult form.

The Conservatory (where Wings of Fancy is located) often gets very hot in the summertime, as it's a greenhouse. But this year with the later season I'm hoping we get lots of comfortable cooler days to enjoy the exotic butterflies. I hope you get a chance to visit too!

Butterfly success!

The suspense is finally over. The first of last fall's black swallowtail chrysalids (see here and here for the beginning of this story) is now a gorgeous butterfly!

Interestingly, the first caterpillar to change into chysalis is now the first butterfly.

After the caterpillars became chrysalids last fall, I just couldn't bear abandoning them outside, even to the relative safety of my garden shed. So I kept them inside on my desk all winter, silent little companions.

Then in early April I moved the chrysalids outside onto my back porch. I hoped the still-cool nights and gradually warming days would trigger the metamorphosis. I wired the twigs to an old chair beneath a maple tree, where they'd get late afternoon sun and still be protected from heavy rain.

I worried something could harm the chrysalids, but this was the safest spot I could find.

I've been checking the chrysalids every couple days since then for any sign of change. I had just about given up when two nights ago, I noticed one chrysalis had suddenly turned dark. I'd read that a day before eclosure the chrysalis skin turns translucent and the adult wing colors show through. I was too tired that evening to really think about it, though, let alone get a photo. Indeed, by the next morning I had totally forgotten about it.

When I got home from work in the evening, I started my normal routine of puttering in the garden. Finally though I remembered to go check the chrysalids.  I ambled into the back yard, not really expecting anything. But what a surprise-- the dark chrysalis was now an empty husk, with a beautifully formed butterfly dangling beneath it! I pelted inside to grab my camera, then spent the next forty minutes or so taking a zillion pictures and marveling at the gorgeous insect.

The butterfly flexed its new wings, allowing me to see the dark markings of a female. Pink cigars, anybody?

Tiny barbed feet clung to the old shell of the chrysalis. I wonder how long she hung there before I got home?

It was neat to be so close I could see the texture of  the antennae and the wings.

Almost ready to go...

Just a few short seconds after the last photo, I watched the butterfly climb up to the top of her twig, pause for half a heartbeat, then spread her wings and waft gently away. I lost her in the sunshine, but presume she soared upward to scope out the neighborhood and find a flower full of nectar. I don't have a lot blooming in my garden yet (the flower bed is still under construction) but I know there are plenty of blossoms nearby. My vegetable garden is also full of vigorous dill plants that sprouted from last fall's seeds, so I hope she returns once she has found a mate. I'll be examining the dill closely all summer, hoping I can repeat the cycle!

Caterpillars Continued: From Poop to Pupation

So to catch you up since my last entry, I did go outside and bring in the original Black Swallowtail caterpillar to raise by hand, the littler one. Good thing I did, too, a few days later we started about a week of straight rain thanks to tropical storm Lee. How do caterpillars survive this much moisture? Even if they could find shelter I’d still think mold or fungus would be a serious threat with all the humidity. Anyway, now I had two caterpillars in the Tupperware container on my desk. (My apologies for taking so long to post, too-- this all happened last weekend, not the one just finished.  The school semester has started, so this week I've been a bit busy.)

Big caterpillar's in the far right of the carrots, little one's hanging under a far left dill stem.

Initial Observations

Boy, do caterpillars poop a lot! I have to say, these caterpillars’ poop, or frass, is some of the nicest smelling I’ve found from any critter. It reminds me of a rich field or forest, all decomposing plant material and fertile soil.  As they moved around and ate they also bruised the dill and carrot greens, releasing those scents too.  My office has been wonderfully fragrant this week! 

I noticed that the little caterpillar didn’t move around much; the big one was more active, roaming from carrot frond to carrot frond and of course eating a ton. The little caterpillar must have eaten too, judging from the two different sizes of frass pellets, but since its head was smaller I guess I couldn’t see the behavior as well. The two caterpillars were distinct individuals with their own preferences.  The big caterpillar, whom you’ll remember I had found in the carrot patch, preferred to eat carrot fronds.  The little caterpillar, who had been on the scraggly dill plants, occasionally tasted the carrots but would always go back to dill and obviously much preferred it.  This kind of worried me since there isn’t a whole lot of juicy dill left in my garden, most of it is dry and yellowed stems. But I picked what flowerheads I could find, and luckily some of the seeds from earlier flowers have sprouted into tender seedlings as well. If I must, I can always buy some organic dill at the grocery store. I’d rather use my own garden produce exclusively though.

My late summer dill patch.

The Drama Begins

I’ve had so much fun watching the caterpillars.  But I didn’t anticipate how much suspense and excitement there could be in caring for these little invertebrates. Since I had placed their container on my desk, I could see them as I worked on the computer.  Early Sunday morning-- two days after I adopted it-- I noticed the big caterpillar was even more active than normal.  It wandered restlessly all over the container, up the carrot stems, across the underside of the paper towel that topped the container, and back down to wander through the foliage again. Occasionally it would explore the dried dill stalk I had intended for a pupation site, but seemed unimpressed by it.

Checking out the dill stalk, with the little caterpillar in the background.

When the afternoon rolled around and the caterpillar was still wandering, I wondered if the dill stalk didn’t suit its preferences.  So I fetched a maple twig from our back yard, one as different from the smooth, pale stalk as possible: rough, dark gray bark, with a fork at the end to provide a choice of different vertical angles even. I wanted to be a good host! Soon the caterpillar discovered the new twig, meandered along it a few times but continued its restless wandering.  It must have walked the caterpillar equivalent of a couple miles, relative to its own length. I am impressed!

I kept both twigs in for a while; later I removed the dill stalk.

But Wait, There’s More

Eventually I realized that the smaller caterpillar hadn’t moved for quite some time.  I hoped it might be getting ready to molt, since I’d read that a period of inactivity often precedes molting. So now I made sure to watch both caterpillars all afternoon. As the hours ticked by, though, the big one just kept hiking around while the little guy rested on a dill flower stem.

Is is something in the air? Both caterpillars get ready.

Finally, at 3:20 Sunday afternoon, the big caterpillar stopped near the top of the new twig, as you see above. It spent the next couple hours in the same spot, turning back and forth every few minutes. Occasionally it would also rear its head and thorax back, leaning out into midair and waving gently back and forth. I also noticed it fussing on the lowest spot of its chosen site, apparently creating a button of silk to anchor its rear end to the twig. (The way a Black Swallowtail makes its chrysalis is first to spin a bit of sticky silk that will hold its rear to the twig, then create a loop of silk-- sort of a safety belt-- that will support it at the thorax while it's busy transforming.  After that it molts into its new chrysalis skin.) While it was working, gentle waves of faint movement also rippled down the caterpillar’s body from time to time, like tiny muscle contractions.

Safety Belt
Two long hours later, the caterpillar seemed satisfied that its hindmost prolegs were anchored securely on the twig.  More lengthwise convulsing ensued for a while. At 5:45 the caterpillar started rearing again, leaning way back into midair and waggling back and forth there. This time though when it returned to the twig it reached way around to the upper side. After fussing there, it reared again, wiggled, and reached around the twig again, this time in the opposite direction. Then it repeated this pattern. It was spinning its safety belt! It worked on the silk loop until 6:25, when it finally stopped. I hope caterpillars aren’t camera-shy, because I took a lot of pictures. 

Spinning the safety belt.

Still working on the safety belt; meanwhile the little guy stays motionless.

Finally done with the safety belt, it's time to rest.

Over the next couple hours it was mostly calm, relaxing in the safety belt that suspended it from the twig, with occasional twitching and fidgeting. I also noted more lengthwise contractions, like it was straining. I assume these were all because it has to loosen its old skin-- from the inside! By 10:00 pm it had pretty much stopped all movement and was no longer physically gripping the twig.

Look Ma, no prolegs!

Do Caterpillars Dream?

Now it hung totally dependent on the safety belt and the silk button. Once in a while it still twitched almost as if it was dreaming, but pretty much it just rested.  I expected it would start molting any minute, but hours ticked past. I stayed up long as I could, but eventually I had to give in. Even though I worried the caterpillar would molt overnight and I’d miss it, I really needed some sleep.

Monday morning when I came downstairs, I was torn between hope that the caterpillar had successfully transformed and trepidation that I had missed seeing it happen. But I discovered pretty much nothing had happened overnight after all.  It was still in the same position. The only change was its skin looked a bit drier and slightly flaccid, and it had taken on a brownish tinge instead of the bright grass green it wore the night before. 

Turning a bit brownish...

The other caterpillar, however, seemed to have come out of its quiescence. I saw it take a few tiny steps upward, then it rubbed its head against the dill stem.  I thought the caterpillar was eating, and that the previous inactivity had been just ordinary torpor. That was it for another several hours though, so I figured the little caterpillar just really liked to sleep.

Surprise

Not a whole lot happened in the container for most of the day. The prepupating caterpillar gradually appeared drier and more flaccid, and both caterpillars periodically twitched a tiny bit, almost as if they were dreaming. I mostly focused on my schoolwork, glancing at the caterpillars occasionally in case anything should happen. I expected there wouldn’t be any excitement until chrysalis time, but then at 4:19 the smaller caterpillar came out of its torpor once again, stretching vertically up the dill stem where it was perched. What was this—was I right the first time in thinking my little caterpillar was about to molt?  I started paying closer attention to it, but the real action took a long time to start. Finally, almost forty minutes later, the actual molt started for the little guy.

The head pushes out first-- the black thing in front  is its old head shield.

First it reared back, wriggling its head back and forth. Then it pushed its head upward, straining, and a new, pale green head finally popped out. The old head covering fell down against the stem, like a discarded mask. The caterpillar proceeded to climb slowly up the stem, squirming and straining to get out of the old skin, and finally waggled its tiny rump to get the last bit clear.  It only took about three minutes total once the shedding started!

The plump caterpillar pulls itself out of the old, wrinkly skin.

All clear! The old face covering fell away too.

The Excitement Doesn’t Stop

Next the caterpillar rested for almost an hour-- to allow its delicate new skin to harden some, and let the pigments in its head develop. You can see in these early photos that it has a completely pale green head. The dark stripes slowly developed over the next forty minutes. Finally at 5:42 the newly molted caterpillar, now sporting bright green stripes rather than the whitish stripes of yesterday, turned around & headed back down toward its shed skin.  I was excited to see the caterpillar devour its old skin (a growing caterpillar can’t afford to abandon those nutrients), so I got ready to take more photos. Just then, however, I noticed the big caterpillar had finally started to split its skin! I took a couple hasty shots of the little caterpillar and switched focus to the big caterpillar. 

Does shed skin even taste good?

You can just barely see the skin splitting over the caterpillar's back.

I’m a Caterpillar Paparazzo

I was so excited this was finally happening. I took a photo every couple seconds so I could record the full sequence. The caterpillar sort of shrugged the skin off over its hump with only a little wiggling, but then needed a whole lot of writhing and thrashing about to get it the rest of the way off.  It was still attached to the twig at the button and its safety belt of course, but within those limits the caterpillar moved a LOT. Imagine trying to wriggle yourself out of a too-tight mummy sleeping bag without being able to use your arms or separate your legs! What an ordeal.

The chrysalis starts to push itself out with great effort.

You can still see the legs on the skin as it peels off the chrysalis.

Just five minutes later the skin had been shucked all the way down to where the caterpillar was still attached to the twig by that silk button.  The caterpillar (now a chrysalis) swung itself back and forth a couple times and finally flung the discarded skin off, letting it fall to the bottom of the container. I guess the old skin must have split around the button, since the caterpillar/chrysalis remained attached to the twig the whole time.

The chrysalis just has to kick the shed skin off now...

Success!

The fallen skin. The other caterpillar didn't seem interested-- maybe it's rude to eat someone else's skin.

Last Step: Camouflage

The chrysalis wriggled a couple more times and then was pretty much still. The fresh chrysalis skin was mostly light green, veined almost like a leaf. I noticed tiny twitches periodically, much like the dream-twitches I noticed earlier when the caterpillar was loosening inside the old skin. By the next morning the chrysalis dried into a crispy-looking pale brown with darker markings.  It also seemed to shrink a bit over the next few days, ending up a tiny shriveled-looking thing. It looks much like a dry, curled-up leaf, to hide its presence over the winter.  It is astonishingly small, especially when I compare it to the freshly molted “little” caterpillar who is quickly growing big and plump. How on earth can the whole caterpillar fit in there, let alone develop those large gorgeous wings? Amazing.

The chrysalis turns brown overnight.

What’s Next

Usually we have about another month of warm weather around here, but Black Swallowtails have to overwinter as pupa. So in order to reproduce successfully, not only do my caterpillars have to make it through pupation, they also have to eclose (emerge from the chrysalis as an adult butterfly) with enough time to find a mate, lay eggs and then have those eggs hatch and make their own way all the way to chrysalis before the bitter winter hits.  The alternative is to enter diapause, where their development stays completely suspended all the winter. They’ll resume metamorphosis in spring. 

The online discussions of rearing Black Swallowtails that I’ve read indicate that Black Swallowtails are very unpredictable, but I suspect I will be chrysalis-sitting at least one, if not both, individuals all winter.  Quite a project! The other butterfly folks imply it’s not too hard though. An unheated shed, like my garden tool shed, is perfect for the almost-butterflies, who’ll stay safely in diapause until the weather warms.  Still I’ll have to check on them regularly, especially if we get any warm spells midwinter, which is common around here. For the time being, I'm still watching the "little" caterpillar grow rapidly bigger and plumper.  As of this posting, it's at least as big as the "big" caterpillar was at chrysalis time, maybe a little bigger. 

Just In Case

But what will I do if my butterflies eclose in the middle of the winter? I suppose I’ll build a large cage in my office for them, with flowering plants to feed the adult butterflies, and even dill or carrot plants to give them a spot to lay eggs if chance should favor me with one male and one female. Who knew that two tiny caterpillars could require so much responsibility? I definitely don’t regret taking them in, however. I’m glad to give them a much better chance of becoming adults than if they’d had to fend for themselves.  Even if they’d survived this week’s rain, their chrysalis perches could have been destroyed during autumn yardwork. I always look for interesting cocoons on dead vegetation before I remove it, and frequently even leave dead plants in place through spring to provide habitat for winter critters, but my neighbors tend to clean out their gardens before frost hits. 

This entry's location: My yard, Montgomery County, MD.

My Dill Dreams Come True

I went into the garden this morning, planning to have a mellow photography session with the basil flowers and whatever bees came to nectar.  But only a few pollinators came by, and I wasn't getting any decent shots.  Then I happened to glance at the leggy, almost-dead dill plants and discovered the one bug I most hoped my garden would host:

A Black Swallowtail caterpillar!

There was just the one-- believe me, I looked for others.  Apparently female Black Swallowtails only lay a couple eggs in any one place.  But I am so thrilled!

I'm torn between leaving it wild in my garden, and bringing it inside to try and hand-rear.  I've never had success rearing caterpillars; when I was little we used to catch caterpillars every summer, in hopes of raising butterflies.  But they would inevitably die within days, partly because my sister and I knew nothing about the care and feeding of caterpillars.  We'd stuff their jar with miscellaneous grass and leaves, poke a few token holes in the top, and set it on the kitchen counter.  So I don't want to kill my only Black Swallowtail.  But on the other hand, I don't want the garden predators to catch it either-- I know my garden is also home to praying mantids, hunting spiders, wrens and chickadees.

For now I've left the caterpillar exactly where I found it.  I feel totally vindicated for leaving the scraggly, flopped-over  dill plants in the garden this long.  I know they look kind of ugly, and have scattered seeds everywhere--next spring I'll be digging out seedlings from the entire garden if not the whole yard. But it was worth it to see the caterpillar! I love having wildlife make a home in my yard.

Eat all the dill you want, little one!

Update: I found another one! The second caterpillar was about twice as big as the first. It's a lot greener, and was living in the carrot patch. Double hooray!

The real reason I planted carrots this year.

I even messed with it a little, poking it to provoke an alarm response. It shoots out a pair of bright orange fleshy horns, called its osmeterium, which apparently also stink (although I didn't notice any smell except the sweet scent of the carrots).

Get away from me!

Then since I had two caterpillars in the garden, I got brave enough to bring the large one inside.  I arranged a cozy little cage for it, with ample carrot greens to eat, a dried dill stalk to pupate from (eventually), and paper towels in the bottom to catch waste.

Home sweet home...

At first the caterpillar was disturbed enough by all the commotion that it stayed frozen on the greenery. But after fifteen or so minutes it moved down the leaf and started eating again! I was so proud.  Now there are several big fat frass pellets on the paper towels. The caterpillar is wandering around quite a bit too.  I am a very happy caterpillar mom.

Today's location: my yard, Montgomery County, MD