What's been eating my bushy seedbox?
Bushy seedbox, (Ludwigia peruviana) a member of the evening primrose family (Onagraceae), has volunteered all over my yard. In a field where we stopped mowing, it's about 12 inches high on a single stem. It's much bigger and bushier along the edge of the pond, reaching five feet high. I've seen some seedboxes growing along the shores of our neighborhood lakes that must be more than ten feet tall even though the books say the height ranges from 10 to 36 inches. I guess "they"weren't thinking about how well plants grow here in Florida. (Update: I found out later that this species is not native to Florida and indeed it's invasive. My initial ID was incorrect, because I was still using my plant ID book that I'd used in Maryland. I've edited the species to reflect the reality.)
The pretty, four-petaled yellow flower is almost an inch across on the bigger plants. The ridged, four-sided, hard seed capsule is quite distinctive and gives rise to the common name. Some of my books state that it is used in dried flower arrangements, but either the birds have eaten them or they fall off, because all the capsules are gone in short order around here. If there are any leaves left in the fall, they'll turn red and I can see some of that coloration already. But the leaves are pretty ratty looking because something's been eating my bushy seedbox.
Something had been eating all the leaves.
I noticed that something ate all the leaves on one stalk. Upon further inspection, I found two big caterpillars or worms. The green one, looked like a tomato worm that I'm sure many of you have seen, was covered with white braconid wasp larvae. They look like grains of rice sticking straight out like a strange punk hairdo. Organic farmers and gardeners know not to destroy worms with the wasp larvae, because they want those tomato worm predators to flourish. The normal mode for getting rid of tomato worms is to hand pick them. Just look for the eaten leaves; you'll find them.
I looked up information on the tomato hornworm (Manduca quinquemaculata) and found that it has eight stripes and a black horn near its tail end, as opposed to the tobacco hornworm, which has seven stripes and a red horn. Both of these worms take on the color of the plant they are eating and they stay on the underside of the leaves making them hard to see except for the substantial defoliation. The adult phase is a hawk moth. In most areas, the tomato worms go through two life cycles in a year, but in northern Florida, they'll go through four cycles. So I guess it's a good thing that the plants are bigger here. Mother Nature has a way of balancing the critters and their food supply.
The sources of information including extension services and universities say with great certainty that the tomato worms will only feed on plants in the tomato family (Solanaceae) which also includes tobacco, petunia, potato, henbane, jimson-weed and of course, deadly nightshade. This is an interesting plant family with weird chemistry and because of its family, Europeans originally thought the tomato was poisonous when early botanical explorers brought it back from the new world. They called it the love apple for its possible aphrodisiac qualities but tomatoes were mostly grown as ornamentals. The Italians started using tomatoes for their sauces first in Europe. The colonists brought tomatoes with them as ornamental plants. Thomas Jefferson served tomatoes at Monticello and in the early 1800's the Cajuns used tomatoes in their jambalayas. In 1820 when most people still believed them to be poisonous, Colonel Robert Johnson ate a whole bushel of yellow tomatoes. People who came to watch him die on the courthouse steps in Salem, NJ must have been disappointed when he didn't.
So this tomato worm was slumming on my boring, nicotine-less bushy seedbox and then it was attacked by wasps. It turned yellow and died there on the stem and either fell off or was picked off by a bird because it no longer matched the leaves. Poor worm. Still haven't identified the other worm, but maybe one of you will know what it is. (Update: Jim Tuttle contacted me and said that both of these hornworms are the same. Here's more on hornworms.)
The other side of a butterfly garden
If nothing is eating your plants, then you haven't provided the larvae, the caterpillars or worms, with the food they need before becoming the beautiful adult butterflies or moths. So when something is eating your plants, it's the other side of growing a butterfly garden. My good friend Lucia Robson back in Maryland grows milkweed on a sunny hill and she cheers when the leaves start disappearing: the monarch caterpillars will eat only the bitter leaves thus protecting the whole species from the blue jays. A functioning butterfly garden won't be perfectly pristine, but as a complete ecosystem the plants and animals coexist and it will look raggedy around the edges. Butterfly gardeners WANT a moth (and butterfly)-eaten landscape.
I asked a manager of a local garden shop if he stocked Florida native plants and species to attract butterflies. He told me that they were too hard to sell because something always ate the foliage, so he'd carry only the plants that looked good on the shelf so people would buy them: mostly aliens. How sad is that? Perhaps some educational information and better marketing would help. How about if he offered free caterpillars to his customers? Hmm. . .
Ginny Stibolt moved to northeastern Florida in 2004 and even though she's a botanist and lifelong gardener, Florida gardening was a shock. She started writing The Adventures of a Transplanted Gardener columns for the Times Union newspaper in Jacksonville. This is one of those columns archived here on Floridata.com for your enjoyment. Now she's written three Florida garden books published by University Press of Florida: Sustainable Gardening for Florida, 2009; Organic Methods for Vegetable Gardening in Florida with Melissa Contreras, 2013, and The Art of Maintaining a Florida Native Landscape, 2015. Check out her blog for the latest news and articles: www.GreenGardeningMatters.com