U.S. # 4736
2013 66¢ Spicebush Swallowtail Butterfly
As the target of many predators, the spicebush swallowtail uses mimicry to protect itself. By imitating other creatures or objects, it wards off birds, spiders, and other preying hunters. The young swallowtail most often begins its life on the leaves of its namesake plant, the spicebush. Scientists have discovered the adult female butterfly has a chemical compound that compels her to lay eggs on this plant, though others are occasionally used.
When the young larva hatches, it eats part of the leaf and exudes silk. This causes the leaf to fold over the larva, creating a shelter. The young larva is generally a brownish color, similar to bird droppings – its first stage of mimicry to ward off predators. When the larva grows older, it turns a yellow-green color and has two large black spots with white dots on its head – resembling a snake. It also has a red y-shaped organ it exposes when attacked, that mimics a snake’s tongue.
The swallowtail’s mimicry continues as an adult, as it resembles a pipevine swallowtail, which is a foul-tasting butterfly many predators know to avoid. The spicebush swallowtail flies close to the ground, unlike most butterflies. It also flutters its wings while it feeds, while other species stop to feed. These traits help give a unique identity to a species that spends much of its life mimicking other creatures.
Tom Engeman of Delaware used computer software to design the Spicebush Swallowtail, as well as the other butterfly stamps in the series so far. Engeman has designed a number of other U.S. stamps and postal stationary, including the entire 60-stamp Flags of Our Nation series and the Liberty Bell Forever stamp.
Value: 66¢ 2-ounce first-class letter rate and 1-ounce nonmachinable first-class letter rate
Issued: January 23, 2013
First Day City: Pine Mountain, GA
Type of Stamp: Definitive
Printed by: Avery Dennison
Method: Photogravure printing in sheets of 200, with 10 panes of 20
Perforation: Serpentine Die Cut 10 ¾
Quantity Printed: 80,000,000 stamps
The Spicebush Swallowtail stamp is the third in a series Butterfly stamps issued for use on square envelopes such as greeting cards weighing up to one ounce. Many envelopes now have a silhouette of a butterfly in the upper-right corner to indicate extra postage is needed.