Over the past few months, visitors to the Arboretum have had the exciting opportunity to witness the miracle of metamorphosis as part of the Arboretum’s Winged Wonders exhibit, on display daily in the Baker Exhibit Greenhouse from 9 a.m. to 5 p.m. through October 29, 2017. From caterpillar to chrysalis to butterfly, there are many different stages of a butterfly’s life cycle. We recently had the opportunity to record a butterfly emerging from its chrysalis in our butterfly nursery, and it inspired me to address many questions that we often hear from our guests. Below you will find the most frequently asked questions about these fluttering beauties.
How long is a butterfly’s full life cycle?
Life cycle length varies greatly depending upon the species. A major factor in a butterfly’s life span is its method of coping with the change of the seasons in our part of the world. For instance, black swallowtails remain in their chrysalis for months so that they can overwinter (hibernate) within that stage, eliminating the need for a food source. Monarch butterflies in the eastern United States famously dodge the winter months by migrating far south to Mexico (though some also overwinter in Florida). As a result, monarchs never lack a food source. Monarchs remain in their chrysalis for around one week, which is typical for most butterfly species. Also, as with most species, the monarch caterpillar hatches from its egg within three to five days and will remain a caterpillar for around two weeks. Adult butterflies generally live for about one to two weeks, though the generation of monarch butterflies that makes the trip south live for several months.
Windows, particularly on sunny days, are a popular place for butterflies to congregate due to the light. No one knows for sure why insects (butterflies included) travel toward light. There are many theories, and the one that most satisfies me is the notion that light indicates an open area. Open areas are easiest for flight and have the greatest opportunity for nectar (food) sources, as well as for finding other insects to mate.
When are butterflies most active?
Butterflies are most active midday, but lighting conditions due to cloud cover can have an impact and usually lead to less active behaviors.
Many butterfly species have a close relationship to a particular plant species, commonly known as the butterfly’s host plant. The host plant provides food for the caterpillars, which is the larval stage of the insect. This is an example of coevolution — when the evolution of one species impacts the evolution of another. Monarchs are milkweed specialists, and their behaviors and physiology demonstrate this relationship. The caterpillars make a cut in the leaf to allow most of the gooey, natural latex to drip out before consuming the leaf. They also have a special sack within their bodies that allows them to store the toxic chemical the milkweed creates rather than consume it. This, in turn, makes the caterpillar toxic to predators. As a result, monarchs are completely reliant on milkweed as their food source, and the decline of milkweed in our landscapes has also impacted populations of monarch butterflies.
Do caterpillars only eat leaves?
Most caterpillar species will only eat leaves (including all the species included in the Winged Wonders exhibit). However, some caterpillars eat flower petals and a few species eat aphids and other insects. One species of the moth caterpillar feeds only off fragments from dead gopher tortoises!
It is a good rule of thumb that animals raised in captivity not be released outside, including butterflies. The wild butterflies at the Arboretum might catch diseases or illnesses from the butterflies in the Baker Exhibit Greenhouse, which would harm our local population. There are also certain genetic traits that local populations have, and introducing farm-raised butterflies from hundreds of miles away would alter the genetics of their offspring and bring about unexpected impacts.
For more information on butterflies, visit the Arboretum’s Winged Wonders indoor butterfly exhibit inside the Baker Exhibit Greenhouse through October 29, 2017. Photo credit: Jeff Gresko, Arboretum volunteer. Video credit: Amy Merchen, Arboretum guest services coordinator.