The similar firefly, missing from science since 1983, is found flashing in a Delaware meadow

A firefly that had not been documented since 1983 has been found again in Delaware, Re:wild said on 22 October. Christopher Heckscher, an entomologist and ecologist at Delaware State University, found the similar firefly (Pyractomena similis) in a meadow in Brandywine Creek State Park.

Short amber pulses on the last night

Heckscher surveyed three sites in Delaware and Maryland in May and June. On the final survey night, 3 June, he recorded the flash patterns of fireflies as they emerged at Brandywine Creek and saw 8 to about 12 insects producing the species' pattern of short amber pulses. He confirmed the identification by examining one under a microscope, where he saw features known only in this species. The other two sites, Fair Hill in Maryland and White Clay Creek State Park in Delaware, yielded none.

“I was confident I had found the species the moment I saw the flash pattern.” — Christopher Heckscher, Delaware State University

The species once ranged across parts of the eastern and southern United States but was never studied in depth, and earlier searches in Georgia and North Carolina had not found it. It lives in mature meadows with shrubs and low vegetation.

Twenty-eight fireflies are lost, many simply unsearched

The find comes with a review in the Journal of Lost Species of every firefly species in the United States and Canada. It lists 28 lost species, which Re:wild defines as having no documented sighting for 10 years or more, plus 69 species with gaps in knowledge of their status and 48 with no data at all.

“The good news is that a lot of these species likely aren't gone forever, they are simply overlooked,” said co-author Candace Fallon of the Xerces Society. Co-author Anna Walker of the New Mexico BioPark Society said fireflies are usually lost not because they have declined but because no one has looked for them.

Rediscoveries like this are part of Re:wild's Search for Lost Species. This week the program also announced that the venomous Bangka slow loris is still alive in Indonesia, unrecorded by science since the 1930s.

Next: how many are there, and where

The next steps are follow-up surveys in similar meadows in Delaware and elsewhere to work out the firefly's range and numbers, and protection of its habitat, including meadows near water. The Colossal Foundation, which partners with Re:wild, is supporting further field work. The species' conservation status has not yet been assessed.