A butterfly with green wings dotted with brown and white eyes sips nectar from a plant with small clusters of white flowers.
Hessel's Hairstreak Butterfly (Callophrys hesseli) Atlantic white cedar provides the sole food source for the globally imperiled Hessel's Hairstreak during its caterpillar phase. © Garry Kessler


A Rare Find in Delaware

The sighting of a Hessels’ hairstreak butterfly is the first on a TNC property in 27 years.

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This spring a Hessels’ Hairstreak butterfly (Mitoura hesseli) was sighted on a southern Delaware The Nature Conservancy property for the first time in almost three decades; the only confirmed sighting on the Delmarva Peninsula in 27 years.

The Hessel Hairstreak butterfly was identified by entomologist Dr. Christopher “Kitt” Heckscher of Delaware State University. This tiny green, black and white butterfly has a wingspan of only one inch and spends most of its time near the tops of Atlantic White Cedar trees, its host plant. It is on the State of Delaware Endangered Species list.

“I consider it one of the region’s most important Lepidoptera conservation targets.  It would be the only known population between New Jersey and southeastern Virginia,” said Dr. Heckscher. “I was lucky enough to be among the group that spotted this butterfly 27 years ago.  It’s a long time between sightings but encouraging to see it again.” 

“TNC works hard to manage our Delaware properties, so they are welcoming homes for native insects, plants and animals,” said Delaware Stewardship Program Manager Natasha Whetzel. “The confirmed sighting of the Hessels’ Hairstreak is such a wonderful surprise and a reminder why conserving open space is so important.”

To protect the butterfly, TNC will not be disclosing the specific location at which it’s been found but the find is an example of how vital it is to protect wildlife habitats, native vegetation and open space for rare and endangered species. There are 120 species of butterflies that breed and reside in Delaware.

The Nature Conservancy is a global conservation organization dedicated to conserving the lands and waters on which all life depends. Guided by science, we create innovative, on-the-ground solutions to our world’s toughest challenges so that nature and people can thrive together. We are tackling climate change, conserving lands, waters and oceans at an unprecedented scale, providing food and water sustainably and helping make cities more sustainable. The Nature Conservancy is working to make a lasting difference around the world in 77 countries and territories (41 by direct conservation impact and 36 through partners) through a collaborative approach that engages local communities, governments, the private sector, and other partners. To learn more, visit nature.org or follow @nature_press on X.