By Adam Hale
Most gardeners know that ladybugs are master defenders. They protect plants from menacing aphids right before your eyes in the light of day. But cute ladybugs are not the only garden guards. There are other beneficial creatures living in your garden, working the night shift to control pest populations.
Predatory ground beetles (Family Carabidae) are a good example of night guards. They are abundant in many Bay Area gardens and feed on soil-inhabiting pests such as cutworms, slugs, and root maggots. These fast-moving creatures have powerful mandibles and terrific eyesight, aiding them in their midnight hunting escapades. Both the adults and larvae are considered active predators.
While ground beetles range in color from black to bright green, they have a couple of unique characteristics that help to distinguish them from beetles that are unwanted in your garden, namely the plant-feeding Darkling beetle. The predatory ground beetle typically has a shiny body and an enlarged basal segment on their hind legs. The larvae can be distinguished by its worm-like appearance and large mandible.
Adult ground beetles have hefty appetites and have been reported to eat their body weight in food each day. These do-gooders enjoy shady and dark areas during the day. If you’d like to attract ground beetles to defend your plants, make sure to provide plenty of leaf litter and mulch. As the sun sets, they will crawl out of their cozy dirt nooks and work to maintain your garden.