Nature and Gardening: Monarch Caterpillars -- At Last!

           I finally spotted a monarch in my yard about a week ago. After disappointingly spotting a few viceroys several weeks earlier, I have been looking diligently for monarchs, and finally saw a female nectaring in my garden. Both swamp milkweed (Asclepias incarnata) and blood flower milkweed (Asclepias curassavica) were nearby. The monarch's wings were a bit ragged and her coloration was faded. Adults only live a few weeks. As I watched, she visited the milkweed, but not the flowers. Instead, she landed on the leaves on the lower part of the plant. Butterflies can taste with their feet so I suspected she was searcing for a place to lay eggs and today I discovered caterpillars! I counted 5 caterpillars in various sizes and instars.

          Finding caterpillars prompted me to examing other milkweed plants around my yard and meadow, where I found several more caterpillars. Naturally I also found lots of orange-colored aphids feeding on the plants. I squished as many as I could with my hands, wearing gardening gloves of course. Aphids suck the juice out of the milkweed that the caterpillars need for food. Monarchs only lay their eggs on milkweed, which is the sole food source for the caterpillars.

          Milkweed contains toxins -- cardenolides.  Insects that eat the toxic milkweed taste bad to predators. Although adult monarchs don't eat the plant, they still carry the toxins from the caterpillar stage to the adult stage. The orange and black coloration of adult monarchs is a warning sign to predators.

          Milkweed plants support of lot of life. I found several insects and butterflies nectaring on milkweed flowers. More of the blood flower milkweeds are currently flowering right now than the swamp milkweeds. Both varieties have produced seed pods already. With seed pods, naturally I found milkweed beetles that feed on the pods as well as the plant. There isn't much I'm willing to do about them. They are too big for me to squish, and of course I can't spray insecticide on milkweed that the caterpillars are eating.

          I have been monitoring milkweed pods in order to harvest seeds to plant next year. The best way to do this is to check the pods regularly. As soon as one splits a tiny bit, I know the seeds are ready to harvest. If the pod opens fully, it is difficult to separate the seeds from the fluff that carries them through the air. That fluff was once used in early flotation devices. By opening the split pod further, I can hold one end of the white part where the fluff is still attached and simply scrape off the seeds, leaving the fluff intact and collecting clean seeds.