The beetle family Phengodidae is known also as glowworm beetles, whose larvae are known as glowworms. The females and larvae have bioluminescent organs. They occur throughout the New World from extreme southern Canada to Chile. The recently recognized members of the Phengodidae, the Cydistinae, are found in Western Asia. The family Rhagophthalmidae, an Old World group, used to be included in the Phengodidae. Larval and larviform female glowworms are predators, feeding on millipedes and other arthropods occurring in soil and litter. The winged males, which are often attracted to lights at night, are short-lived and probably do not feed. Females are much larger than the males and are completely larviform. Males may be luminescent, but females and larvae have a series of luminescent organs on trunk segments which emit yellow or green light, and sometimes an additional head organ which emits red light, as in railroad worms. This family is distinct from the fireflies (family Lampyridae), which may also be called "glow-worms" in its larval stage. According to a few recent studies, Phengodidae might possibly include (or be sister taxon to) the long-lipped beetles, which are primarily differentiated from phengodids by the unusual modifications of their mouthparts; long-lipped beetles were treated as a family Telegeusidae but are most recently treated as a subfamily within the family Omethidae. Genera Acladocera Adendrocera Brasilocerus Cenophengus Cephalophrixothorax Cydistus Decamastinocerus Distremocephalus Eurymastinocerus Euryognathus Euryopa Howdenia Mastinocerus Mastinomorphus Mastinowittmerus Microcydistus Microphengodes Neophengus Nephromma Oxymastinocerus Paramastinocerus Paraptorthodius Penicillophorus Phengodes Phrixothrix Pseudomastinocerus Pseudophengodes Ptorthodiellus Ptorthodius Spangleriella Steneuryopa Stenocladius Stenophrixothrix Taximastinocerus Zarhipis References Sean T. O'Keefe, "Phengodidae", in Ross H. Arnett, Jr. and Michael C. Thomas, American Beetles (CRC Press, 2002), vol. 2 External links Phengodidae in J. F. Lawrence, A. M. Hastings, M. J. Dallwitz, T. A. Paine and E. J. Zurcher (2000 onwards). Elateriformia (Coleoptera): descriptions, illustrations, identification, and information retrieval for families and sub-families. glow-worms on the UF / IFAS Featured Creatures Web site Bioluminescent insects Beetle families Beetles of North America Beetles of South America Insects of Central America