If you pick up a flower pot set on the ground, it's not unusual to find all sorts of nocturnal creatures hiding beneath it during the day.

When you lift the pot, these little fauna scurry to find another dark place for protection. Some of these scampering fellows are likely to be predacious ground beetles. You may also occasionally find a lost ground beetle indoors, hiding under a laundry basket or pile of clothes in the laundry room. When encountered, the first reflex we have is to stomp on them.

Few of us feel like letting them go on their merry way, but you are encouraged to learn to recognize them as friends, not foes that need to be squashed.

According to WSU Extension Entomologist Dr. Arthur Antonelli, the different types of ground beetles found in Washington feed on a variety of "insects and insectlike creatures, many of which are garden or house pests, such as cutworms or house fly maggots. One specific group of ground beetles feeds on snails and slugs." While they may also feed on some desirable critters, they are considered a beneficial insect because of the good they do.

Predacious ground beetles belong to a very large insect family of beneficial beetles called carabids (Carabidae family). Just in North America there are several thousand named species and over 40,000 in the world. They get the name of "ground" beetle because the majority of these beetles in temperate zones are terrestial, living close to the soil under pots, rocks or garden debris, yet there are a number of tropical species that live above ground in trees.

To protect this valuable insect resource in your garden, you need to be able to identify them. Keep in mind there are numerous species and they don't all look alike. The ground beetles found in Washington range in size from 1/8 of an inch long to 1 1/4 inches long. They're generally elongated with a body that tapers to a smaller head with long legs and long antennae. Most ground beetles we will encounter in our yards and gardens will be black or dark brown in color, but there are some that have more of a purple to metallic green appearance. These characteristics may be hard to verify because the beetles are quite fast, especially when scurrying for cover.

The ground beetle starts out life as an egg that hatches into a larva. It's interesting that the larvae feed using "external digestion" where they spit their digestive juices onto their food, turning it into liquid nutrients. They then suck up the juicy digested matter. The larvae are wormlike, somewhat flattened, dark brown to cream in color, and a bit tapered at each end. Like the adult, the larva also has noticeable large mandibles (jaws). The larva then turns into a pupa before emerging as an adult. This all takes about a year for most of the ground beetles in Washington. Depending on the species, the adults may live or one to three years ... unless some callous gardener flattens them with their shoe.

Antonelli notes that the four most common species of ground beetles in Washington are the European ground beetle, the green pubescent ground beetle, the common black ground beetle, and the boat-backed ground beetle. One of the ones most common in our region of Washington seems to be the common black ground beetle with lengthwise grooves on the wing covers over its back.

Antonelli cautions us that ground beetles are "often the victims of broad-spectrum insecticides used around the home and garden, especially when insecticides are used beyond an intended target plant or site." When we apply pesticides to large areas, such as the foundation of the house, to reduce the population of a particular pest, we may be shooting ourselves in the foot by killing predators. Predatory insects, such as ground beetles, are responsible for helping us keep pest numbers down. It's important to protect these valuable garden predators, not kill them. Predacious ground beetles are our friends.

Beetle trivia

Researchers and farmers at OSU's Integrated Plant Protection Center have been developing "beetle banks" where they create raised beds 4 to 6 feet wide situated in the agricultural fields. These beds are planted with native bunch grasses and provide an area where ground beetles can thrive and eat harmful insects in crops planted nearby.

When threatened, many native species of ground beetles secrete stinky chemicals to deter animals from eating them. One such beetle is the"bombardier beetle" that emits toxic chemicals from its anal glands. These chemicals explode into puffs out the rear end of the beetle with an audible sound. It's said to discourage frogs or other predators from eating them. I bet it does!

You can raise your own ground beetle to observe. Go to www.earthlife.net/insects/gb-care.html for information on how.

* Marianne Ophardt is a horticulturist for the Washington State University Extension Office in Benton County.