Good Bugs

As a follow-up to last week's focus on spiders, this week we'll look at other "good bugs" - those beneficial to gardens. The term "good bug" may seem like an oxymoron until we mention a few by name: lady bug, praying mantis, honey bee, ground beetle. These are bugs you WANT in your yard - bugs that either help plants or eat the bugs that eat plants. Let's start with the most unlikely on the list: Ground beetles.

Ground beetles are from the family Carabidae. Although sometimes confused with cockroaches at first sight, these common beetles seldom invade homes and can be useful in the garden. There are about 2,500 known species of ground beetles in North America. Adults, referred to as "Carabids," can be anywhere from 1/16 to 1-3/8 inches long, flat and elongated with a narrow head and hard wing covers. They are generally nocturnal, running quickly at night and feeing on potentially harmful insects. Usually found under rocks, logs or boards, they love to chow down on slugs, snails, cutworms and root maggots, and the larvae of many harmful insects. The worst thing we can say about ground beetles is that some varieties can produce an offensive odor - garnering them the moniker "stink bug" or "stink beetle."

Pictured above is the ground beetle and larva of the genus Calosoma in the family Carabidae. These beetles are often called "caterpillar hunters." During April of 2005, when there was an abundance of painted lady butterflies in the Anza-Borrego Desert, these beetles were very abundant - feeding off the pupae. For more information and some great pictures of other types of local beetles, see the website here.

If you have an over-abundance of ground beetles, eliminate any debris or rubbish outside where they may hide. Weather strip or seal off openings and crevices in outer walls in order to exclude them from the home. Also, it may be helpful to reduce exposed night lights, as these night-active bugs are often attracted to lights. Try to remember, even though they may not be the most attractive bugs around, they are not harmful. If you find you have more than you can handle, call a pest professional.