The other day, I was admiring the Butterfly Weed (Asclepias tuberosa) in Catch the Wind when a Pearl Crescent (Phyciodes tharos) lighted on the flowers and began to nectar. I photographed the butterfly and continued my walk down the path.
When I got back to the office to download and catalogue the day’s photos I noticed something odd on several of the photos. There was a caterpillar just behind the butterfly’s right wing. It was a Monarch caterpillar.
A few weeks earlier Ranger Rock showed me a photo on his iPhone of an adult Monarch nectaring on the same plant. I asked him if the butterfly was just nectaring or had he seen it laying eggs. He said that he hadn’t noticed anything he would call egg laying regarding the butterfly’s behavior.
We all know that Monarchs have a close relationship with milkweed, their existence depends upon milkweed. Monarchs lay their eggs on the leaves of the plant and their caterpillars eat the leaves, and sometimes flowers, of the plant.
As the butterflies leave their winter quarters in Mexico each spring in March it’s the second or third generation of Monarchs that make it to Canada each year. The butterflies that had been wintering in Mexico, upon reaching the first patches of milkweed on their journeys north, stop, nectar, lay eggs on the plants and soon die. The offspring from that generation continue north, laying eggs as they go with successive generations moving north with the spring.
Butterfly Weed is a milkweed and our Monarch, the one photographed by Rock, apparently laid eggs on the Butterfly Weed out in front of the Bungee Jump in Catch the Wind.
The next day I went out to Catch the Wind to see if I could find more caterpillars on the plants. I did.
The butterfly must have also paid visits to several other smaller Butterfly Weeds down the path, I found caterpillars on those plants as well.
Most of the caterpillars that I found were of the same size, no more than three or four days old, others appear to be one or two days old. Either there were other Monarchs moving through our area a day or two after Rock’s initial sighting or that same butterfly stayed in the area, laying eggs on successive days.
I just love milkweed. It attracts such a variety of creatures, many of which, like the Monarch, are specific to milkweed and are only found on milkweed. One such creature is the Swamp Milkweed Leaf Beetle (Labidomera clivicollis). I discovered a pair of the leaf beetles on the leaves of the plant in the top photo.
So, no matter where you are, if you pass a milkweed, no matter what variety of milkweed, stop and have a look, you never know what you may find.