Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Calendar
Upcoming Events

Photos of insects and people from the 2022 BugGuide gathering in New Mexico, July 20-24

National Moth Week was July 23-31, 2022! See moth submissions.

Photos of insects and people from the Spring 2021 gathering in Louisiana, April 28-May 2

Photos of insects and people from the 2019 gathering in Louisiana, July 25-27

Photos of insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12


Previous events


TaxonomyBrowse
Info
ImagesLinksBooksData

Family Phengodidae - Glowworm Beetles

Rolled Up Bug - Phengodes Distremocephalus opaculus? - Distremocephalus opaculus Western Banded Glowworm - Zarhipis integripennis - male beetle larvae - Phengodes railroad-worm  - Phengodes plumosa Phengodes - male Unknown - Phengodes Glowworm - Phengodes
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Coleoptera (Beetles)
Suborder Polyphaga (Water, Rove, Scarab, Long-horned, Leaf and Snout Beetles)
No Taxon (Series Elateriformia)
Superfamily Elateroidea (Click, Firefly and Soldier Beetles)
Family Phengodidae (Glowworm Beetles)
Other Common Names
Glow-worms, Railroad Worms
Synonyms and other taxonomic changes
the Asian Rhagophthalmidae (~30 spp.) formerly included here as subfamily are now treated as a separate familyl(1)
Explanation of Names
Phengodidae LeConte 1861
Numbers
23 spp. in 6 genera of 2 tribes north of Mexico, ~250 spp. in ~30 genera total(2)
Identification
Adult males have variously shortened/narrowed soft elytra, branched antennae, and bulging eyes; adult females are larviform (often all but impossible to tell from fully-grown larvae) and, like the larvae, have bioluminescent organs(2)
Adult females larviform, differing only slightly in external appearance from mature larvae in absence of larval setae from sterna and terga of abdominal segments 9 and 10, presence of gonopore beneath large, transverse fold on abdominal segment 10, and presence of compound eyes (2).
Also, per J.M. Cicero: "Adult females are much larger, having supernumerated beyond the male instar count and/or grown larger on nutritional bases; we don't know which of these factors is responsible for the larger size. Zarhipis and Phengodes larvae, at least, have strong opaque dorsal sclerites while in the female, those markings are bleached and weak. Lastly, females have a semi-circular slit on the penultimate ventrite that is associated with a copulatory gonopore. Larvae don't have either."
Range
New World; in our area, mostly so. US, with 1 sp. (Phengodes plumosa) reaching ON and all Mastinocerini restricted to sw. US (CA-TX)(2)(3)
Food
adult females and larvae feed on millipedes(2); adult males do not feed
Remarks
mostly nocturnal; males come to lights; females much more commonly encountered than larvae(4)
Print References
(5)