Cottonwood Leaf Beetles

Remember learning the life cycle of butterflies? Egg, caterpillar (larva), chyrsalis (pupa), butterfly (adult). For some reason, every child in the U.S. learns this, but we’re left thinking that butterflies are the only type of insect that do this. Not true! Most insects have this life cycle, called complete metamorphasis. Beetles are one example, and I was reminded of this when I saw a bunch of these hanging from Coastalplain Willow (Salix caroliniana) leaves:

At first I was quite confused by the sight, but then I spotted one of these:

Having read some insect books lately, I recognized them as beetle larvae. Suddenly, I was aware that the willows around me were speckled with larvae chomping away at the leaves.  Without much searching, I spotted a few larvae hanging upside down, getting ready to pupate.

And to top it off, I even found a couple adults on the leaves too, and was later able to identify them as Cottonwood Leaf Beetles (Chrysomela scripta).

There it was, the complete beetle life cycle just inches from my nose (yes, I also saw some eggs, but didn’t get a photo).

On another note, the willows that the Cottonwood Leaf Beetles were eating are a major concern at Corkscrew Swamp Sanctuary. Until recently, at the center of the sanctuary there has been a large marsh dominated by low-growing plants like sawgrass, pickerelweed, and arrowhead, but in the last couple decades, Coastalplain Willows have overtaken the marsh, drastically changing everything about the ecosystem. It has been an extremely difficult species to control on other properties nearby, but maybe the Cottonwood Leaf Beetles will be able to help. They are known to do serious damage to cottonwoods and aspen in more northern parts of the country. More info on them here.