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Glowworm (Phengodes spp.)


Detailing the physical features, habits, territorial reach and other identifying qualities of the Glowworm.

 Updated: 6/8/2018; Authored By Staff Writer; Content ¬©www.InsectIdentification.org




An unusual beetle, the bioluminescent and beloved Glowworm has delighted generations and inspired song.



The larval form of the Glowworm Beetle is called a Glowworm. The larva is long and tubular like a worm, and it emits a yellow, orange, or green light from its body using bioluminescence, not heat. Some species can emit a red light from their head. They eat mostly other crawling things like millipedes, slugs, snails, and even other insects. A toxic cocktail is injected into their prey as they bite it. This causes the internal parts of the prey to dissolve whereupon the Glowworm eats it. They are found in soil, leaf litter, grasslands, and even in caves, where they light up the roof like stars.

Adults look similar to lightning bugs, or fireflies. They are orange and black with large bulging eyes on the sides of the head. Glowworm Beetles have long antennae with wispy, feathery lashes. Males, not females, have wings. They do not have a hard wing covering (elytra) like other types of beetles. Larvae and females, not males, can glow. She looks somewhat like her larval form and somewhat like an adult. Her beacon of light is how she attracts a mate since she is not as mobile as the male.

Collecting Glowworms for captivity actually reduces their ability to successfully reproduce and maintain a population in a specific area. Admiring Glowworms in their habitat and allowing them to finish the mating process allows for an annual summertime display. Glowworms were the subject a fun tune sung by the Mills Brothers in the early 1950's. Their harmony and lyrics are still easy on the ears. Look for Glowworm Beetles day or night, but enjoy the illumination of their worms after the sun has set. It doesn't hurt to hum their song, too.




Taxonomic Hierarchy
Kingdom: Animalia
  Phylum: Arthropoda
    Class: Insecta
      Order: Coleoptera
        Family: Phengodidae
          Genus: Phengodes
            Species: spp.
Identifying Information
Scientific Name: Phengodes spp.
Other Name(s): Glowworm Beetle
Category: Beetle
Size (Adult; Length): 11mm to 65mm (0.43in to 2.54in)
Colorwheel Graphic Colors: black, orange
Descriptors: large, feathery antennae, lightning, bug, glow, light, belly, wasp-like, flying, harmless
Territorial Map
Alaska  
Hawaii  
Prince Edward Is.  
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Territorial Reach (A-to-Z)
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Canadian National Flag Graphic
Alberta
British Columbia
Manitoba
New Brunswick
Newfoundland and Labrador
Nova Scotia
Ontario
Prince Edward Island
Quebec
Saskatchewan
Mexican National Flag Graphic
Mexico
Note: An insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above as they are driven by environmental factors (such as climate change), available food supplies and mating patterns. Grayed-out selections indicate that the subject in question has not been reported in that particular territory. U.S. states and Canadian provinces / territories are clickable to their respective bug listings.




Beetle Anatomy
Graphic showing basic anatomy of a common North American Beetle insect
1
Antennae: Beetles have a pair of antennae on the head used as sensors.
2
Head: The head is home to the insect's eyes, antennae, and mandibles (jaws).
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Thorax: Holds the three pairs of legs as well as vital internal organs.
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Elytron: One of two wing cases on a Beetle that protects its wings (plural: elytra).
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Wings: Appendages used for flying and kept under the elytra until needed.
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Abdomen: Houses organs related to circulation, reproduction, and excretion.
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Legs: Beetles have three pairs of legs located at the thorax, numbering six legs in all.