The next time you are digging in your garden plot on a hot summer day, be on the lookout for our colorful and winged insect friends, the butterflies. While the idea of bugs in the garden might detract the squeamish, butterflies are more often than not a welcome visitor in urban gardens - and in fact many gardeners will try to attract plants they find at home and garden centers that claim to be a "magnet" for butterflies. Indeed, common nursery stock plants like Butterfly Bush (Buddleia davidii) do attract many species of butterflies, giving the false impression that planting ornamental garden flowers will increase the amount of butterflies. It's deceiving because there is a difference between attracting butterflies and supporting the life stages of butterflies. Most garden plants that people plant provide a source of nectar for them to feed on, but that's it. They do not provide the necessary elements to support their growth and development, which for butterflies takes place over four main stages (see figure 1).
|Figure 1: Typical life cycle of most species of butterflies|
First, a butterfly lays it's eggs. But not just anywhere, Many species of butterflies will only lay their eggs only on certain types of plants. For example, the monarch butterfly (discussed below) will only lay eggs on Milkweed (Ascplepias spp.) and nothing else. It is believed that butterflies have evolved in close association with a host plant, and that certain plants offer necessary nourishment required for a butterfly's development and growth. For example, the monarch butterfly needs milkweed because milkweed offers the basic nutrients and energy needed for caterpillars to grow.
The caterpillars grow as they eat leaves and stems from their host plant. Each stage in the growth of a caterpillar is known as an instar. The caterpillar will shed its skin between each instar, not unlike that of a snake. After the last instar (there are usually about 5 of them, depending on the species of butterfly), something rather unusual happens. The caterpillar finds a place under a leaf and begins to pupate to form into a chrysalis. During this stage, the entire body structure of the insect is altered, leading to the final stage as....you guessed it! A butterfly!
So what kinds of butterflies might you see in an urban community garden like the Taylor Street Farms in the University Village neighborhood of Chicago? There are several species of hardy butterflies that have adapted to urban environments in our region. Here are just a few of them:
Monarch Butterfly (Danus plexippus).
|Figure 2: A female monarch butterfly. Photo credits: Kenneth Dwain Harrelson|
Red Admiral (Vanessa atalanta)
|Figure 3. Photo credits: Didier Descouens|
Silver-spotted skipper (Epargyreus clarus)
|Figure 4. Photo credits: John Brunelle|
Clouded sulphur (Colias philodice)
|Figure 5. Photo credits: Megan McCarty|
Cabbage White (Pieris rapae)
|Figure 6. Photo credits: Sarefo|
Viceroy (Limentis archippus)
|Figure 7. Photo credits: John Brunelle|
Eastern Tiger Swallowtail (Papilio glaucus)
|Figure 8. Photo credits: John Brunelle|
The next time you are out pulling weeds or watering your garden plot, stop to smell the roses and admire the butterflies that find refuge in our urban garden farm.
You can learn more about Chicago's urban butterflies at: http://www.naturemuseum.org/the-museum/blog/6-common-butterflies-you-ll-see-in-chicago-parks-and-gardens
- Butterflies - difference between attracting butterflies and supporting the life stages
- Life stages of butterflies
- Urban butterflies: monarch, viceroy red admiral, orange-spotted skipper, tiger swallowtail, clouded sulfur, cabbage white