Common Name
Nelson's desert firefly
Scientific Name
Nelsonphotus aridus
Recent Synonyms
None
Adult Male Size
8 mm
Diet
Unknown
Firefly Atlas Category
Lost species
Nelson's desert firefly is a poorly understood species reported from a handful of sites in the Sonoran Desert of southern California and northern Mexico. Very little has been published about its life history, habitat requirements, distribution, or population trends. The last known observation of this species is from 2005, when a single adult male was seen along the Borrego Palm Canyon Trail in Anza Borrego Desert State Park in California.
Conservation
Status
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species is an inventory of the global conservation status and extinction risk of biological species, maintained collectively by scientists worldwide.Data Deficient (DD)
NatureServe
The NatureServe conservation status ranks use a standardized methodology to assess the extinction risk of species, with a focus on the US and Canada. State wildlife agencies and natural heritage programs use these ranks to prioritize species for conservation actions.Global status unrankable due to lack of information (GU) Not yet assessed in California (SNR)
Species of Greatest Conservation Need Lists
Species of Greatest Conservation Need (SGCN) are lists of species included in State Wildlife Action Plans, identifying animals and plants that need the most conservation attention and resources at the state and region level.None
US Endangered Species Act
The Endangered Species Act is a United States law that provides legal protections to species that are officially listed as endangered or threatened by the US Fish and Wildlife Service.N/A
Threats
Although no specific threats to this species have been identified, it is likely that habitat degradation and drought affect this species. Adult females are suspected to be flightless; if this is the case, they would be vulnerable to ground disturbances such as trampling by livestock, habitat alterations, and impacts from ORV use.
Location
Distribution
USA
California
Mexico
Sonora
Details
The species is known from only a few locations in southern California and one site in the mountains east of Hermosillo, in Sonora, Mexico. In addition to the most recent observations along Borrego Palm Canyon Trail in Anza Borrego Desert State Park, this species has been documented from Palm Springs and a site 8 miles north of the junction with Deep Creek and Horsethief Creek in Riverside Co., as well as the Sentanac Canyon Gaging Station
in San Diego Co.
Habitat
Known records are located at elevations ranging from 549 - 1,066 meters (1,800 - 3,497 ft.) within lower areas of the Sonoran Desert. The single individual observed in Anza Borrego Desert State Park was found along a trail near a wash with some water present. Additional details concerning this species’ habitat associations are unavailable.
Behavior
Activity Period
It is unclear if adults are diurnal, nocturnal, or crepuscular, although at least one adult male has been observed during the day. The species has been collected or otherwise observed in February, May, and July. It is possible adult emergence is timed with spring rains, although this needs more investigation.
Flash Pattern
It is unknown if adult males and females are bioluminescent.
Sources
Cicero, J.M. 2006. Two new genera and one new species of firefly (Coleoptera: Lampyridae: Lampyrinae: Lampyrini), with notes on their biology. Pan-Pacific Entomologist 82(2): 200-207.
Fallon, C., and J. Cicero. 2021. Nelsonphotus aridus. The IUCN Red List of Threatened Species 2021: e.T164049126A166771688. https://dx.doi.org/10.2305/IUCN.UK.2021-1.RLTS.T164049126A166771688.en. Accessed on 26 March 2026.
Fallon, C. and J. Cicero. 2021. Nelsonphotus aridus: a firefly. NatureServe Explorer. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.1215488/Nelsonphotus_aridus. Accessed on 26 March 2026.
Gross J. 2005. Nelsonphotus aridus. BugGuide. https://bugguide.net/node/view/36406. Accessed on 26 March 2026.
