In mid-May I was leading a hike at the Stone Head Nature Preserve in Brown County, Indiana. I found a larva on a dock (Rumex) plant. I had no idea what it was, other than it was a moth (and the quick photos that I took of it with my phone are so bad it will probably remain unidentified). It was black with orange or red spots or blotches, and was fairly spiny. I pointed it out to the group, and then we moved on. As we walked down the trail, Geoff, a friend of mine on the hike asked, “Jeff, if there was a similar black and red caterpillar, with spines similar to that one, but on willow, what do you suppose it would be?” My ears perked up. “On willow?” “Yes.” “Feeding in a group by any chance?” “Yes, there was a swarm of them, or at least last time I looked a few days ago.” I stopped the hike. “Well, those are undoubtedly Mourning Cloak larvae, and I would love to rear a few. I haven’t seen them in years.” I continued with a brief review of the life story of the Mourning Cloak.
The Mourning Cloak (Vanessa antiopa antiopa) is one of the tortoiseshells, a group of the “true brushfoots” in the subfamily Nymphalinae. The Mourning Cloak occurs throughout most of the Northern Hemisphere, inhabiting temperate woodlands of the United States and Canada, Europe, and Asia. Mourning Cloaks are one of the relatively few species of butterflies which overwinters as an adult. The adults emerge from hibernation in early spring—they are often the first butterfly seen on the wing in Indiana—and soon mate and begin to lay eggs. The eggs are laid in clusters on the twigs of willow and poplar. The larvae feed voraciously, and remain as a group throughout their lives. After about two weeks of feeding, they form a chrysalis, then after about two weeks as a chrysalis the adult butterfly emerges. Most butterflies immediately begin to seek mates and reproduce after emerging from their chrysalis. Although studies have not been done in Indiana, studies elsewhere suggest that Mourning Cloaks are different. They apparently do not seek mates after emerging from their chrysalis, but instead, once the heat of summer begins, seek a sheltered spot such as a tree cavity or under loose bark, and enter a summer dormant period, or aestivation. In late summer they emerge from aestivation, fly around for awhile, and then seek a location to pass their winter dormant period, or hibernation. In early spring they emerge from hibernation, and then begin to search for a mate. As a result of their summer aestivation, Mourning Cloaks are probably our longest-lived butterfly, surviving as an adult from when they emerge from their chrysalis in June to the following April, or approximately ten months.
Mourning Cloaks, because of this special life history, and because of their gorgeous coloration, are one of my favorite butterflies. However, I had not reared one since the mid-1980s, and I was anxious to try to photograph the larvae. After I finished telling the story of the Mourning Cloak’s annual cycle to the group, Geoff said he would be right back, and disappeared. We continued with the hike, and finished in about an hour. As we were dispersing at the end of the hike, I discovered that Geoff had reappeared. While we were on the hike, Geoff had driven to his house, jumped in his canoe, paddled over to the willow on the edge of his pond, stood up in the canoe (thankfully without tipping it over), and cut the willow branch with the munching larvae that was hanging over the pond. He greeted me with a plastic bucket filled with a few inches of water and a willow branch. Happily chewing away on the leaves were ten Mourning Cloak larvae. Needless to say, I was thrilled.
I took the larvae home and immediately began trying to take photos. As luck would have it, despite my best efforts, my favorite photo is still the one I took immediately after Geoff plopped the bucket down at my feet. I also took photos of the larvae when they assumed the hanging “J” shape as they prepared to become a chrysalis, as well as the chrysalises that appeared shortly thereafter.
During the two week wait for the adults to emerge, I decided I should try to take video of the emerging adults. I acquired some studio lights to supply continuous light on the chrysalises (rather than my usual flash setup for taking stills) and traded in an old lens for a second camera body. When the adults started appearing, I took video of the emerging adults. I used my trusty 200mm macro, but also used my 105mm macro mounted on the second camera, so I could take two different angles at the same time. I have a lot to learn about videography, but it was fun trying. Below is a clip of one of the adults emerging from its chrysalis.