Zebra Swallowtail and Pawpaw
by Gary Pendleton
Back in 1982, as Calvert County Day Celebration was being planned, the Calvert County Board of Commissioners solicited nominations for county symbols. Calvert already had a seal; a flag; an official bird, the purple martin; and a county tree, the Bald Cypress. The commissioners were seeking suggestions for official county fish, flower, dog, sport and insect.
John Fales of Huntingtown, a retired entomologist, answered the call. In a letter dated July 22, 1982, addressed to Mary Harrison, President of the Board of County Commissioners, he made his nomination for official county insect: the showy Zebra Swallowtail, which is common in all of Calvert County. Fales is also credited for successfully promoting the Baltimore checkerspot as the Maryland state butterfly.
His letter also mentioned pawpaw, a common woody shrub or small tree, which is the host plant of the zebra swallowtail and on which the female butterfly lays her eggs. The leaves of pawpaw are consumed by the caterpillar stage of the zebra swallowtail by night; they spend the daylight hours hiding in the leaf litter.
Both the zebra swallowtail and pawpaw are North American relatives of tropical families. In Peterson Field Guides for trees and butterflies, I found that the range maps for each species were practically identical: eastern U.S. exclusive of New England and the northern Great Lakes states. In the Audubon Society Guide to North American Butterflies, author Robert Michael Pyle points out that although it has a broad range, the Zebra Swallowtail is only found near where the pawpaw grows.
If you want to attract zebra swallowtails to your garden, you dont need to go the trouble of planting pawpaw trees. The adult butterflies are attracted to many kinds of nectar sources: flowers such as purple coneflower, butterfly bush, butterfly weed, swamp milkweed, garden phlox and other plants that you can grow from seed or buy at a local nursery. Some wilder plants such as Joe Pye weed, swamp milkweed and dog bane grow in meadows and can sometimes be purchased from specialty nurseries. Check the Maryland Native Plant Society web site for sources of these and other native plants: www. mdflora.org.
Pawpaws grow in dense stands in wet woods and near streams and rivers. They have very large leaves and reach about 40 feet. Other common names are custard apple and the unappealing sounding fetidbush. The wood has no commercial value, but the fruits are eaten by foxes, raccoons and humans.
The fruits have thick, yellowish-orange flesh, which has the consistency of custard plus multiple, large brown seeds shaped like lima beans. They have a delicious, rich and creamy flavor, but their potential as an agricultural product is limited, because they dont keep well and, by contemporary standards, the fruit itself is unattractive.
To harvest pawpaws, first find a stand of trees. Try searching in a stream valley. You might find that only a relatively small percentage of the trees bear fruit. If you keep looking, you may find some ripe fruits on the ground. Young trees have slender trunks. Try gently shaking the trunks to loosen the ripe fruits, which will fall to the ground.
As tasty as they are, I find that the flavor is so rich that after eating one or two Ive had my fill. Im always tempted to greedily pack a bunch to take home, but in my experience they are never as good as when eaten right there.
Special thanks to Dwight Williams for his help in researching the history of Calvert Countys official insect.