Glad I could share some learning and some laughs with everyone. I set my alarm for 9:00 am because I had to get blood work done at the doctor, so naturally I woke up at 8:00 am. But what was weird is that I was awoken by thunder! First, the fact that it rains in April is a miracle itself, but to have thunderstorms? This climate change thing is getting serious. It stopped raining while I went to the doctor, but was very dark when I came out. I managed to go out and pick caterpillar food while it was starting to sprinkle again. I was picking Cudweed and thought I had found another caterpillar but the nest was empty. I mean, there was silk and frass and a head capsule where it molted, but no caterpillar. I'm going to assume it became a beautiful butterfly because nothing bad happens to caterpillars in my world.
Well, except that the Gulf Frits on the Corkystem Passion Vine in front of the house got that melty disease. It just liquefies them and it's really gross. I saw a cat up on the Jatropha which kind of overhangs the vine and I was going to pick him up and put him back on the vine and he just oozed apart on my fingers. And then I found three more dead! I did find one that looked okay so I moved him to the 'Lavender Lady'. I just hope he's not a carrier because I have a bunch of cats on that vine.
Now, I mentioned that one of my books talked about the introduction of Cabbage Whites from Europe so I thought I'd share that info with you. The book is part of a series called "The Nature Library". This book is "Butterflies" and was written by Clarence M. Weed, D. Sc. It was published in 1926 by Doubleday, Page and Company. FYI, you can find a lot of old books for free on Google Books if you're into that sort of thing. I like to see how science has progressed.
So in the book the author talks about how many of our most destructive insects were imported from Europe. He calls the Cabbage White the "Imported Cabbage butterfly" and says in Europe it fed on cabbages and turnips. He remarks that the insect has been known for centuries in Europe. Now, it is rare even these days to know how exactly a non-native species was introduced. But they know that the Cabbage White first appeared in Quebec in 1860, and then in the region of New York City in 1868. The author says from these two points the butterfly spread in various directions until in 1871 it covered the whole of New England and various parts of New York and New Jersey. From then on it spread through various ports of entry, most likely through the shipments of cabbages from one place to another. Within thirty years it had become a serious pest over practically all of the U.S. and Canada.
The author then talks about two species that have almost gone extinct due to the competition of the Cabbage White. One he names is the Checkered White, which I can assure you is doing fine in Florida. This wasn't a great year for them as I think the late freeze interfered with their host plant, Virginia Pepper Grass. But you usually see lots of them. BAMONA says they can be rare locally and at the edges of their natural range. But if you look at the map of sightings there are plenty of them all over the U.S. so I think they must be doing all right. I will say that I have only ever seen one Cabbage White in this area of Florida. I think maybe it's too hot for them.
The other species he mentions is the Gray-Veined White (Pieris napi). However, current taxonomy shows that this is most likely a superspecies with many subspecies. Even the author back in 1926 admits that eleven varieties in the U.S. have received scientific names as they are so distinct. One is the West Virginia White. I have a modern book on West Virginia butterflies that I use when I visit Grandma. I know it says that the West Virginia White butterfly has become exceedingly more rare since the Cabbage White was introduced. I think the Cabbage Whites may emerge earlier and thus get a head start on the host plants leaving none for the competition of the other species. I have to admit, I've seen Cabbage Whites in WV but no WV Whites.
So there's your history lesson for the day. It's too bad these scientists realized they had an invasive species problem, but not many tools to work with to stop them. Even now, it's hard to get rid of them once they get established. (Ask me about my skunk vine problem. No wait, don't.) And even though we have chemicals that could kill Cabbage Whites, we would end up killing the other butterflies and moths, too. Same with invasive plants - do we want to risk spreading herbicides all over? In some cases, it may be worth it, but in others, maybe not. Then there's the old "let's introduce another non-native that eats the first non-native and see what happens." They're trying that right now here in Florida with some insect that eats Air Potato.
I don't have all the answers folks, but we can at least discourage people from doing dumb things. Like if someone asks you to ship caterpillars or eggs across state lines - and yes this has happened to me - just say no! Even if the butterfly is native to that region, too, you can interfere with local populations that may have evolved their own characteristics (like all the subspecies of Polydamas Swallowtails). Also, I would highly discourage anyone wanting to do a butterfly release at a wedding, funeral, etc. Some of that is because I have this idea that caterpillars and butterflies aren't commodities that should be bought and sold (with the exception of scientific institutes and such). But it's also just a bad idea and usually doesn't turn out as well as you think. I mean, you have to keep the butterflies in the fridge until you get ready to release them! That just seems mean. Plus, I think it just feeds into this idea that nature is something we can control and use as we like and I think we can all see how that's working for us.
Okay, I got on my soapbox again. I'm going to go chill and pet some caterpillars. But probably not the Spicebush. They have the smelliest stinkhorns, in my opinion, and I'm not taking the chance!
