One of our most beautiful beetles is an inch-long ground beetle called a caterpillar hunter, or fiery searcher. These beetles are very fast, rarely fly, and are commonly seen during the early to mid parts of summer when their favorite prey, caterpillars, are most abundant.
The colors of the beetle are nothing short of spectacular. Completely metallic, the wing covers, or elytra, are strongly ribbed and a bright green. The legs, head and thorax, as well as much of the underside of the insect, are a deep bluish purple. Highlighting these colors, the edges of the elytra and the pronotum (top of thorax), and part of the head, are an orange red.
Caterpillar hunters forage at night, but are easily seen during the day if they remain out near sidewalks and buildings that are lighted at night. They can move rapidly, occasionally not bothering to hide before sunrise, so they are sometimes encountered in the morning. I've also found them when I'm digging in the garden and disturb leaves and mulch. They are sometimes seen on the trunks of our live oak trees, probably because of the number of prey insects located in the branches.
I've never found a larval caterpillar hunter, but they are long, slender, and fast moving, resembling a fat centipede with only 6 legs. They also feed on insect pests. The beetles mature during their first year but may live for as long as three years as an adult. Eggs are laid singly on the ground. Although they are a beneficial insect, they are best left alone when encountered. Their strong jaws can give a healthy bite and they also spray a sickening smelling chemical in self defense. This smell can be nauseating but washes off easily with soap and water.