Beetles, Pacific Northwest
Fire Colored Beetles have chewing mouth parts and hardened front wings that meet in a straight line down the back of the abdomen when closed. They are quite interesting to observe.
Commonly encountered in the Pacific Northwest, most fire colored beetles are a little less than 2.5 cm long, but some species are much smaller. Most have dark wing covers and many are marked with orange or red on the head, legs, or thorax. Some species are orange all over their bodies. Fire-colored beetles have long, straight antennae.
Like all beetle larvae, fire colored beetle larvae look completely different than the adults. Larvae are long and worm like with distinct, flattened bodies and horn like projections on the final abdominal segment.
Like all beetles, fire colored beetles undergo a complete metamorphosis with egg, larval, pupal, and adult stages. Females lay eggs on decaying wood. Upon hatching in the summer, larvae live and feed underneath the loose bark of decaying trees. As they grow, the larvae shed their skins several times before pupating. Adults emerge during the summer.
Fire colored beetle larvae are commonly found underneath the loose bark of decaying trees in our Islands forests. Little is known about the biology of the larvae, but they are believed to be predators and likely feed on other wood dwelling invertebrates like worms, termites, ants, grubs and other beetle larvae.
Larvae are slow moving and soft bodied, so they are easy prey for larger predators, especially centipedes, which live in the same habitat. Even less is known about adult fire colored beetles, but they have been observed visiting flowers where they probably feed on pollen and nectar. I have observed them on flowers many times.