Lightning bugs, also called fireflies or lightning beetles, are known for their ability to blink their taillights on and off. Even the larvae of these beetles have small spots that shine and these organisms are commonly called glowworms as well. Lightning bugs are beneficial insects that eat other insect larvae, snails and slugs. Some adult soldier beetles resemble adult lightning bugs, while sowbugs or pillbugs look like lightning bug larvae.
Description of a Lightning Bug
An adult lightning bug (Photinus spp.) is a winged beetle that measures 7/16 to 9/16 inch long. It has a dark-colored soft body with brownish-black wing covers, edged with a light yellow to yellowish orange stripe.
A section of the thorax, called the pronatum, extends over the lightning bug's head. The pronatum is reddish yellow with a dark spot in the center. When viewed from above, a lightning bug appears to have two body sections.
The tail end of a lightning bug contains a chemical called luciferon or luciferase, and it produces a glow that flashes on and off. The pattern of the flashing attracts a lightning bug of the opposite sex for mating.
Lightning bug larvae have flattened elongated segmented bodies, a pair of antennae and three pairs of legs. They range in size from .06 to .4 inch long.
Description of a Soldier Beetle
Soldier beetles are related to lightning bugs and some in the Chauliognathus and Podabrus species resemble them. A soldier beetle has a black elongated body from ½ to 1 inch long with reddish markings on the head and/or wings and the pronatum does not cover the head. When viewed from above, a soldier beetle has three body sections and extremely long antennae.
Description of a Sowbug
Lighntning bug larvae look like sowbugs, which are not even insects. A sowbug is actually a land-dwelling crustacean with a multiple-segmented body about ¼ to ½ inch long. Some sowbugs are called pillbugs or roly-polies because they roll up into balls when threatened.
Both lightning bugs and sowbugs have oval segmented bodies. A sowbug has a rounded back, a flat bottom and it breathes through platelike gills on the underside of its abdomen. It has seven pairs of legs and two pair of antennae, one of which is very small.