Sunday, June 13, 2010

Black Swallowtail Butterflies

On Friday, I was inspecting the bed that has the cucumber, carrots, and beets in it. I noticed one carrot that needed to be thinned out. It was a late starter and was very close to another, more mature carrot, so I plucked it out. Just before tossing it aside, I noticed a little dark spec on it. It was some kind of larvae or caterpillar. It looked a little bit like a lady bug larvae, but not quite. I discovered about 5 others on the carrots, they weren't on any other plants.

You've probably guessed by the title that what I discovered were the larvae of the black swallowtail butterfly.

So I've been reading up on these guys a little bit. I learned that they lay their eggs on plants in the carrot family, especially carrots (duh), parsley, fennel, dill and Queen Anne's Lace. It amazes me how my 2 rows of carrots, surrounded by decidedly non-carrot plants, were found by these butterflies.

I also learned that butterflies go through growth stages, called instars. I determined that my caterpillars were in their 1st instar.

1st Instar black swallowtail larvae on carrot.


I admit I was concerned about what they would do to my plants. I am used to garden enemies that I do not care about conserving whatsoever (think earwigs, ants, slugs) if it comes to my veggies or them. I do not use chemicals but there are many other ways to get rid of pests.  I was faced with a clash between two things I value. I really did not want to lose my crop of carrots. I also would not want to harm the swallowtail's chances. So I did the only reasonable thing, nothing :)

I decided to just see how things progressed and my plan B was to buy some parsley and relocate them to a corner of the yard. Well, the next day I could only find three of the caterpillars and they were already looking larger than the evening before. But the carrots seemed to only have minimal damage. I don't think it's enough to do long term damage at this point.

Today when I checked on them I was sad to find only one caterpillar. But the one left is truly amazing! I can't believe how much they change in such a short period of time.

2nd or 3rd instar black swallowtail caterpillar.


First thing tomorrow I am going to put a nice solid stick in the bed to give this guy a place to form a chrysalis. I've read they rarely do it on carrots because they are not all that sturdy but if you provide another stick they will often use that. Stay tuned for further developments.

3 comments:

Melissa-ParadigmFarms said...

It IS amazing that they managed to find your carrots. Nature is so incredible in so many ways when we take the time to notice it!

RuckusButt said...

Exactly! When I read that part I literally said, out loud, "but how do they know???"

It's possible I would have missed all this if I didn't pull that one carrot. I feel like a kid in elementary school learning (or re-learning) the wonders of life.

mangocheeks said...

Sometimes its just best to let nature do its thing.

Lets see how your carrots turn out.