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Glow Worms in Oregon

The species of glow worm found in Oregon is known as Zarhipis integripennis. It's also found in western Washington and California. The adults are a little over a half-inch long. The female is wingless and yellow or tan while the male is light yellowish-brown. The larvae live under bark and piles of leaves in forested areas.

Beetles vs. Worms
- Glow worms are not actually worms. They are the larvae of a beetle and belong to the Order Coleoptera. Both the larvae and the adult beetle glow. The female of the species remains in a larval form and so they look like worms. Males have short wing covers and feathery antennae. Fireflies are also a type of beetle, but not of the same species as the glow worm. Fireflies belong to the family Lampyridae, while glow worms belong to the family Phengodidae.
Bio-luminescence
- Animals that glow use bio-luminescence and emit a cold light in which almost 100 percent of the energy used is converted into light. While fireflies use their lights for mating or for warning predators, it is not clear why glow worms glow, considering they spend a lot of time underground. Male glow worms find female mates by following the female's pheromone rather than by looking for her light. Researchers think that the glow of a glow worm serves to warn prospective predators that they will not make a tasty meal. Females glow when they curl their bodies around their eggs.
Life Cycle
- The glow worm glows during every phase of its life. The embryos of glow worms give off light and can actually be seen glowing while inside the egg. The larvae have a number of light organs; the distribution of these light organs varies among species. In Zarhipis integrippenis strips of light shine between body segments, and along the side of the body segments are spots of light. The females have these points of light while the males have only a dim luminescence.
Hunting
- Glow worms hunt millipedes for food. Zarhipis integripennis larvae will stalk a millipede far bigger in size than themselves. The glow worm gets onto the millipede's back and wraps itself around its prey. It reaches for the millipede's neck and deftly breaks the main nerve in the neck. After dragging the dead millipede underground, the larva then removes the millipede's head and begins to feast on its meal, eating into the body cavity. The meal might take several days for the glow worm to finish.

Insects & Science