Identificaciones de anna_walker

Colorado Fireflies

I think this is a first for us, and I did not know that fireflies even existed in Colorado. One evening we looked down on the sidewalk outside the front door of our cabin outside of Florissant Colorado, 8872 altitude, and noticed something glowing. It turns out that this is the female, of the fire fly “Microphotus pecosensis” sometimes called the Mountain glow worm. It does not have wings, but does glow as observed in our picture. The biology of the western glow worms is poorly understood. There are several species. The female is wingless with a large light organ on the tip of the abdomen. The male is winded but non-luminous although young males may show some light from larval light organs.

A friend found this glowing on the ground near a building in the evening while we were looking for owls with a guide. The (very knowledgeable) guide and I thought it was a glow worm, Phengodidae, but this opinion was corrected on BugGuide. It is a...
Firefly - genus Microphotus (6 North American spp., 13 mm, apparently adult female, which is larviform in this genus)
Updated ID and caption 9/10/23, based on BugGuide comments and range from Green (1959).
Microphotus chiricahuae Green, 1959 (adult female, 13 mm)
Also posted at:
https://bugguide.net/node/view/2251916
See discussion on BugGuide for ID notes, summarized below.

References

• BugGuide species page (Microphotus chiricahuae) https://bugguide.net/node/view/2293869
• Evans, Beetles of Western North America (Princeton Univ. Press, 2021), p. 263 (M. angustus male); p. 22, fig. 8d (larviform female of Microphotus)
• Green, Revision of the Species of Microphotus, with an Emendation of the Lampyrini (Lampyridae). The Coleopterists Bulletin, Vol. 13, No. 3 (Sep., 1959), pp. 80-96 (https://www.jstor.org/stable/3998947)

Quoting comments on BugGuide:
"This is an adult female of Microphotus pecosensis or M chiricahuae, can't know which yet, but note the clavate antennae that occurs in both species.... Note the retractile head and undifferentiated dorsum in the leading picture...these are adjectively larval characters, but the tarsi with segments and two claws, and antennae with scape, pedicel, flagellomeres, are adult characters... these features figure in critically toward understanding larviforms. (joeCicero)"
Range quoted in Green's description of the species indicates that only chiricahuae is found at this locale, not pecosensis.