I am sure everyone is seeing butterflies in their gardens this time of the year.
They are beautiful flying insects with large colorful scaly wings. Like all insects, they have six jointed legs, three body parts (head, thorax and abdomen), a pair of antennae with a club or knob at the end, (moths have feathered antennae), compound eyes and an exoskeleton. They belong to the order Lepidoptera (includes moths).
Lepidos is Greek for “scales” and ptera means “wing.” Their wings are different from wings of any other insects, which are colorful, with iridescent scales in overlapping rows.
It is estimated that there are about 150,000 different species of butterflies and moths. Their development is closely linked to the evolution of flowering plants (angiosperms) during the Cretaceous period, about 130 million years ago.
Butterflies are found all over the world, but most species are found in tropical areas. They can fly only if their body temperature is above 86 degrees. They sun themselves to warm up in cool weather.
As they age, their wing color fades and becomes ragged. Many butterflies migrate to avoid cold weather. Most migrate short distances like the Painted Lady, the Red Admiral and the Common Buckeye, but a few like the Monarchs migrate thousands of miles.
Butterflies (and moths) undergo complete metamorphosis in which they go through four different life stages: egg, larva (caterpillar), pupa (chrysalis) and the beautiful flying adult.
The larva stage of the caterpillar spend most of their time eating leaves. Its first meal, however, is its own eggshell. A few are meat eaters, like the Harvester butterfly, which eats wooly aphids. They can only sip liquid food using a tube-like proboscis, which is a long, flexible “tongue.” It uncoils to sip food and then coils into a spiral when not in use.
Most butterflies live on nectar from flowers. Some sip liquids from rotting fruits and some, like the Harvester, pierce the body of wooly aphids and drink the body fluids.
Some of the more common butterflies seen in southern Virginia (which I am now seeing in my flower garden) are the Eastern Tiger Swallowtail, one of the earliest arriving ones and our state butterfly, and one of the largest. Its host plants (those plants which they will lay their eggs) are the tulip poplar, wild cherry and lilac.
The Black Swallowtail lays its eggs on parsley, fennel, dill, carrots and Queen Anne’s Lace. Another frequent visitor is the Red-spotted Purple whose favored host plants are wild cherry, tulip poplar and black oak.
The Clouded Sulfur, a very common butterfly in yards and gardens, lay eggs on clover, alfalfa and vetch. The Long-tailed Skipper have two very long tails extending from the hind wings, they prefer beans, crucifers and canna lilies as their host plants. This particular butterfly, also known as the bean leafroller, is regarded as an agricultural pest because it feeds on bean crops.
Just yesterday, I observed the Great Spangled Fritillary, one of my favorites. It is the most commonly seen fritillary in the Eastern U.S. Violets are its host plant. These butterflies are long lived and can be seen well into September. Possibly the most talked about butterfly is the Monarch. Their host plants are the milkweeds, which they lay their eggs singly under the leaves.
The caterpillar will eat both leaves and flowers. Milkweeds contain cardiac glycosides, a toxin, which are stored in the caterpillar and adult, making them distasteful to predators. Both common milkweed and swamp milkweed are food for the larva.
One of the reasons for the decline of Monarchs is a loss of habitat and the use of pesticides along roadways. The Monarch is mimicked by the Viceroy butterfly, which looks very similar, and is common to Southern Virginia. Their host plants are willows, poplar, apple, cherry and plum.
The Monarch migration is extraordinary. They rely on instinct to find their way to the mountain forests of central Mexico. Their numbers are diminishing and as previously mentioned a lack of suitable host milkweeds, are a large part of the problem.
Anything we can do to establish pollinator gardens (for bees and butterflies) are crucial to their survival. Host plant abundance determines the survival of the species.
Things we can do are: grow a variety of pollinator-friendly flowers; protect and provide bee nest sites and caterpillar host plants; avoid using pesticides, especially insecticides; and spread the word to friends and neighbors!
Good sources to learn more are The Complete Book of North American Butterflies, editor Paul A. Opler; Peterson’s First Guides on Insects, Christopher Leahy; Xerces Society Conservation Campaign; Virginia Native Plant Society and talk by Sam Droege, 2015.
While we are all still practicing social distancing due to COVID-19, and all county buildings are closed to the public, if you have gardening questions, you can best reach an extension master gardener or extension staff member by sending an email to firstname.lastname@example.org or email@example.com. Keep washing your hands and wearing your mask when you go to a public place to observe butterflies.