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

Upcoming Events

National Moth Week photos of insects and people. Here's how to add your images.

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

Discussion, 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

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Photos of insects and people from the 2012 gathering in Alabama

Photos of insects and people from the 2011 gathering in Iowa


Family Phengodidae - Glowworm Beetles

Western Banded Glowworm - Zarhipis integripennis Insect - Phengodes Wireworm in Virginia?  - Phengodes Orange Phengodes - Phengodes Phengodes - male Male, Phengodes arizonensis? - Phengodes Phengodidae, lateral - Phengodes - male Phengodes species ID? - Phengodes
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
23 spp. in 6 genera of 2 tribes north of Mexico, ~250 spp. in ~30 genera total(2)
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)
Distinguishing adult females from larvae, 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."
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)
adult females and larvae feed on millipedes(2); adult males do not feed
mostly nocturnal; males come to lights(4)