A Place to Call Home: The Butterflies of the Snetsinger Butterfly Garden
Updated: Feb 25
Lisa Schneider, Penn State Extension Master Gardener, Centre County
Tom Tudek Memorial Park in Ferguson Township offers many avenues for outdoor fun, from
picnic pavilions and walking trails to a dog park, playground, and soccer fields. It’s no wonder that it is the most visited park in the Centre region. But it’s not just humans who enjoy this space; it’s also home to a vast array of native plants and their pollinators.
The Snetsinger Butterfly Garden Habitat (SBG) is an educational site of approximately 3 acres located in the northwest portion of Tudek Memorial Park. It’s a diverse ecosystem with over 40 species of resident butterflies, many native bees and birds, and hundreds of native plants that serve as food and shelter for pollinators and other wildlife. Its mission is to educate the public about the importance of pollinators and their habitat as critical components of many ecosystems.
The Discovery Garden at the Snetsinger Butterfly Garden Habitat is home to many
butterflies and other pollinators. Photo credit: Pam Ford.
Located on a former agricultural field, the site was first developed under the direction of Dr.
Robert “Butterfly Bob” Snetsinger and his wife Wendy, who created the garden as a tribute to
their teenaged daughter Clare, who (like Tom Tudek) passed away at the age of seventeen. In
2007, the Penn State Extension Master Gardeners of Centre County became involved in
developing and maintaining the Garden as a major educational resource for the community.
Numerous other organizations serve as Park Partners, providing outreach support while using the site to conduct research or other educational activities.
While visitors to the park enjoy the obvious beauty of the many flowers in the Garden, these
blooms aren’t the sole ingredient in its design. A ‘layered landscape’ of native trees, shrubs, and herbaceous plants provides habitat for all stages of the pollinator life cycle (egg, larva, pupa, adult). Native trees and shrubs serve as crucial host plants for many butterfly species, as well as providing food and cover for bees and birds. Most plantings have been chosen with a particular pollinator guest in mind.
The mourning cloak (Nymphalis antiopa) is one of the earliest butterflies to be seen in spring, and can even be spotted during warm spells in January or February. It’s one of the longest-lived butterflies (up to 11 months) and has a rather unusual lifestyle.
Adult mourning cloak butterflies are among the first to be seen in the spring.
Photo credit: Erik Karits
Native trees are essential for mourning cloaks. In the SBG’s Woodland Garden, trees such as quaking aspen (Populus tremuloides) serve as host plants where females lay their egg masses in spring. When the larvae hatch, they feed voraciously as a group in a large web built among the leaves. When mature, the caterpillars will ‘go walkabout’, leaving the tree to search for a sheltered spot in which to pupate.
The new generation of adults emerge from their chrysalides around the time of the summer
solstice and feed briefly. Unlike most butterflies, they aren’t too interested in the nectar of
flowers, preferring tree sap (oak is a favorite), aphid honeydew, or rotting fruit. As summer
temperatures soar, they are on the hunt again—this time, for a cool shady spot where they can aestivate (suspend activity) till early fall.
When the cooler days of autumn arrive, adults rouse once more to feed and build up fat reserves for winter. The mourning cloak overwinters in a hibernaculum (sheltered spot), often beneath loose tree bark, in brush piles (such as the brush fence in the SBG’s Backyard Bird habitat) or even under the eaves of garden sheds. Their unique ability to survive winter as an adult butterfly is due to a combination of traits.
Like other insects that overwinter, mourning cloaks manufacture glycerol, an antifreeze
compound which keeps their cells from being damaged by the freeze/thaw cycle. Additionally, the high sugar content of their blood lowers its freezing point. Mourning cloaks are among the hairiest of butterflies, and this provides more insulation from the cold. Their dark wings are extremely efficient at absorbing solar heat as they bask on sunny days. And finally, they can generate additional heat by doing isometric exercises with their flight muscles. These factors all work together to help the mourning cloak weather the frigid temperatures of winter.
Spicebush swallowtail caterpillar. Photo credit: Matt Ford.
Swallowtail butterflies are frequently spotted at the SBG, and the caterpillars of eastern black
swallowtail (Papilio polyxenes) can often be found enjoying the bronze fennel in the Discovery Garden. But there’s another member of the family that is drawn to the Garden by its favorite restaurant–the spicebush swallowtail (Papilio Troilus). This glamorous butterfly, with its elegant black wings washed with iridescent blue, depends on the native shrub spicebush (Lindera benzoin), for three quarters of its life cycle.
Eggs are laid on the underside of the new leaves of the spicebush (found in the SBG’s Shrub
Showcase). Young larvae are well-camouflaged, as they look a bit like bird droppings, but the
shelters they construct can help you to spot them. The tiny caterpillars chew a slit near the tip of a leaf and spin silk across it. As the silk dries, the leaf curls over, forming a sheltering tent where they can hide from predators by day. The mature (fifth instar) caterpillar sports the same green coloring as spicebush leaves, and its prominent false eyespots are an additional deterrent to predators.
Adult Spicebush swallowtail butterfly. Photo credit: Lenora Larson
In three to four weeks, the caterpillar is ready to pupate, forming a chrysalis that is attached to a twig by a silk pad at the head, and a narrow silk band or ‘saddle’. It may look like a delicate arrangement, but it’s actually quite strong, able to support some generations of chrysalides right through the winter. As the chrysalis ages, its color changes to orange and finally to brown. Once spring arrives, adult spicebush swallowtails can be seen nectaring on long-tubed plants in the Garden such as Joe Pye weed and milkweed.
Common milkweed (Asclepias syriaca). Photo credit: Jeffrey Hamilton
Park visitors are drawn to the vivid summer display of flowers in the Garden, and they’re not
alone! Monarch butterflies are attracted by bright annuals such as Mexican sunflower (Tithonia) and zinnias. These short-lived selections provide a quick hit of color (and nectar) for pollinators, but native herbaceous perennials are the backbone of the Garden’s floral design. Native milkweed (Asclepias) is the host plant for the monarch butterfly; it is the only food the monarch larvae can eat. Females lay their eggs on the milkweed plants so that when the caterpillars hatch, their food source is immediately available. The Monarch Waystation section of the Garden was planned with these popular pollinators in mind, offering something for every stage of the monarch’s life cycle: Milkweed (food) for eggs and larvae; puddling areas (water) and nectar flowers for adults; and shelter for developing chrysalides. In this way, the monarchs are encouraged to make the Garden their summer home, rather than just a quick nectar pit-stop.
The monarch butterfly is unique in its winter survival strategy–it avoids the cold by heading
south. All of the monarchs we see in central Pennsylvania migrate along a corridor known as the Eastern Flyway, part of a larger route which stretches from Canada to Mexico. The butterflies in our area begin to set off in early fall, usually in early to mid-September. Because a monarch’s life cycle is relatively short–about one month–there can be several generations of monarchs born in one season at the SBG. Migrating monarchs, sometimes called the ‘Methuselah generation’ are born in late summer and will live much longer (up to 8 months). These butterflies have no interest in mating or laying eggs; they spend all of their time searching for nectar, storing it as abdominal fat to fuel their long journey.
The monarchs fly for hundreds of miles, gliding on thermals when possible to conserve energy. Like anyone on a long journey, they face many hazards along the way – adverse weather conditions, predators, high-speed traffic, and scarcity of nectar sources, to name a few. The monarchs must make regular stops to refuel with nectar, so late-blooming native flowers such as asters are essential to their progress.
An adult monarch butterfly with MonarchWatch ID tag. Photo credit: Faith Lucchesi.
By late November, if all goes well, the monarchs reach their winter home in the Oyamel fir
forests of Mexico. This small mountainous region is a unique habitat, with temperatures and
humidity levels that are perfect for the overwintering monarchs. They cluster together on the
branches of the firs, protected by the trees and each other. In early spring, this generation of
monarchs will take to the skies once more, retracing their route north towards emerging
milkweed plants. Here they will lay eggs, creating the new generation that will continue the
journey back to their summer homes.
Each September, SBG volunteers participate in MonarchWatch’s tagging program, a citizen
science project designed to help track the monarch’s annual migration to Mexico. Butterflies are carefully netted and a specially coded tag is affixed to the discal cell of the monarch’s
underwing. These tiny adhesive tags are waterproof and weatherproof, and do not harm the
butterfly or affect its ability to fly. If a tagged monarch is recovered in Mexico (or anywhere else along the route), the tagger is notified. In 2019, two monarchs tagged at the SBG were found in Mexico!
These are just a few of the many butterflies and other pollinators that make their home at the
Snetsinger Butterfly Garden Habitat, drawn by their host plants and a bountiful, three-season buffet of nectar. For the careful observer, there is always something new to discover in every season!
If you’d like to learn more about pollinators or native plants, visit the Snetsinger Butterfly
Garden website (www.snetsingerbutterflygarden.org). Here you’ll find a list of native plants suitable for the Centre region, sample garden plans, information about tours and special events, and more. There’s also a full directory of the butterflies, birds and bees of the SBG.
Lisa Schneider is a Penn State Extension Master Gardener in Centre County. As a member of the Snetsinger Butterfly Garden Habitat project, she develops and presents educational programs on pollinators and native plants. She is a frequent contributor to the SBG’s Facebook page and maintains the SBG website’s blog.