Monarch caterpillars find home in Toumey Nursery greenhouse

By Susan Trull on Sep 9, 2009


Monarch butterfly on common milkweed


Monarch caterpillar

JW Toumey Nursery raised milkweed plants for use on the Ottawa National Forest. While still in the greenhouse, monarch butterfly caterpillars found homes on the seedlings.

At the request of the Ottawa Botany Program, the JW Toumey Nursery in Watersmeet, Michigan, took on the task of raising common milkweed plants (Asclepias syriaca) in their greenhouse. Seed was collected on the Forest, and sown into containers at the Nursery. Once large enough to be transplanted out, these plants would be used in native plant and pollinator gardens, wildlife openings, and restoration projects. Milkweed is a very important plant in the life cycle of the monarch butterfly (Danaus plexippus) because the caterpillars' only food source is milkweed plants. Additional milkweed plantings on the Forest would help this vulnerable butterfly to maintain population numbers.

In late July, 2009, a Nursery worker went to check on the milkweed seedlings in a greenhouse. She was concerned to find numerous caterpillars on the plants, eating the foliage. It turned out these were Monarch butterfly caterpillars: adult butterflies had found the plants in the greenhouse and laid eggs to hatch on the required food source. Toumey personnel left the caterpillars to their business and soon saw chrysalises formed as the caterpillars pupated to become adults. The adults hatched out, leaving empty chrysalises and chewed milkweed seedlings, which are expected to recover for their original purpose. Toumey's greenhouse has become a pollinator waystation for these special insects!