Wednesday, May 3, 2017

Spring has sprung, although here in Nebraska we've had a lot of cold, wet weather. But temperatures are getting better and the insects are starting to emerge.

Last spring, I raised some Cecropia (Hylephora cecropia) caterpillars. One of my colleagues found a female and she laid eggs, so he took some to raise in his lab and I raised about 10 of them in my office. This is the largest moth in North America, but they start out as tiny black caterpillars:

Throughout the summer, I fed them (they eat a number of plants, including ash, box elder, lilac, cran- apple, and maple), and they progressed through several stages, or instars.

They become vibrant green with pretty yellow and orange/red "knobs." In their final instar, they are several inches long!

Once they are this big,  it's time to pupate! They spin a cocoon among the branches/leaves of their food source, then pupate within it.

Out of my 10 caterpillars, 4 of them lived to pupate. Their growth and development occurred from about May through July. This species only has one generation per year, so the moths will not emerge until the following Spring.

I put the cocoons in the refrigerator all through the winter, as this emulates the cold months when they are in diapause. This April, I removed them and 3 weeks later, the first of the four emerged. It was a male I named Titus.

Unfortunately, I could not release him as we've had a few cold, rainy days, and it would have been certain death. The adults do not feed and only live about a week, so their main purpose is to find mates and lay eggs. I was hoping a female would emerge, and one did a couple days later. Here is Athena. She is much larger than Titus, and he was large enough!

Sadly, when I got back from the weekend, Titus had banged his wings up all around the cage, and did not have a lot of time left. I am not sure that he and Athena actually mated. I released both of them yesterday when it was warmer. I wanted to give Titus some time outside before dying, but Athena I am hoping found a chance to mate.

I still have two cocoons left and hopefully these moths will emerge as well. It was an amazing experience being able raise this insect from caterpillar to moth!