The monarch butterfly migration was in full swing earlier this month, and I got a pic of this one at Meadowlark Botanical Gardens in Virginia.
This is a photos of a Monarch butterfly, laying eggs on a milkweed plant. Happens all the time, but there is more to this relationship than simply a butterfly finding a good place for the young to grow up.
There is way more to this story than I can get into here, but two things are worth knowing. First, the milkweed plant contains toxic chemicals, and second, that even though monarch numbers have been way down in modern years just planting more milkweed isn't a perfect solution.
So, the milkweed plant is toxic, specifically containing cardenolides that are not fun to eat. But the larval butterflies, you know, caterpillars, eat up milkweed like crazy. In fact, it is pretty much all they eat, from at least of the 27 species of milkweed in North America.
And as for the toxins, well, they sequester them. This allows these cardenolides to stay in their body through metamorphosis and arrive in the adult butterflies, having no seeming effect on the animals. But you still won't like it if you eat these toxins, so chowing down on a monarch will likely induce vomiting or similar stomach distress. Animals that eat a monarch butterfly learn that this is not good food, and avoid them in the future. Nifty little strategy they've got going there. Side note: the very tasty Viceroy butterfly mimics a monarch's colors to not get eaten since it looks like the awful-tasting one.
So with the numbers of monarchs decreasing (mainly due to habitat loss and pesticide spraying), a grand plan was hatched to have gardeners plant more milkweed. Seems very reasonable, since milkweed makes for a nice garden plant and will attract the pretty butterflies. Well, all is not perfect here. Seems like most all of the available milkweed plants to gardeners in the US are tropical milkweeds, which have a problem.
Milkweed can carry a parasite that is hard on the butterflies, and they can pick it up during the caterpillar stage while eating the leaves. They then pass it on to the adults, which weakens them severely and can prevent them from having the strength to migrate (many go all the way to Mexico!). This whole problem has historically been kept in check by all the milkweeds dying off each winter along with most infected adults. Each year the unaffected adult butterflies return to relatively unaffected milkweed.
But tropical milkweed is different. In parts of the US, like southern Texas, it does not die out but survives the winter. This provides both for continuing the infection and also a side problem whereby some butterflies now do not continue their migration but just stop there as the milkweed remains present (and continues to infect them).
So, monarchs have had it tough lately, even with a large effort to help them out. And this is just a small snippet of the whole story, but certainly an interesting story to learn.
We have a lot of very large butterflies at the Firestone Center, but as the name suggests this one is even bigger than most. Pretty when sitting and colorful when flying and the tops of the wings can be seen.
A couple of butterflies are named after design elements on their underwings that look like punctuation marks. The question mark, comma, and green comma, hoary comma and gray comma are the ones I know.
Here is a Green Comma, alternately called the Faunus Anglewing.
The Hacienda Baru is an eco-resort with property that abuts the Firestone Reserve. We went over there for dinner one evening which is always a treat. Inside their butterfly garden I found these two...
In a fig tree outside the garden, I found a pretty caterpillar (fig tree is host plant).
This year one of the student science projects is to determine how far various species of butterflies travel on the Firestone Reserve. Cool project. Today they set up some of the butterfly traps.
First up this morning were the final two flights for the drone mapping.
And then other projects are moving along as well. Spiders are starting to get mapped and some wildlife cameras are being set up.
And a couple of our insect friends
A very nice day in northern Virginia and Fall is upon us.
The great spangled fritillary is a mid to late summer butterfly. They are large, feed in the open, and are quite showy.
I was only in a little corner of the western side of the marsh. Would like to see more of this place.
Keith Christenson - Wildlife Biologist