The Rove Beetle—Actively Protecting Your Gardens

The rove beetle is a beneficial insect that eats decaying organic matter. And what makes this beetle even better is that it feeds on mites, springtails, mites, nematodes, slugs, snails, fly eggs, and the eggs, larvae and pupae of root maggots, especially the cabbage and onion maggots.

Some rove beetle species are predatory, while others (particularly those from genus Aleochara) are parasitic.

These beetles often resemble a tiny scorpion as the tip of the abdomen is held up in the air.

At 1/10 inch to 1 inch (.25-2.5 cm) long, they're too small to be confused with scorpions, though.

They're very fast, which is useful for preying on other insects. The adults are active, strong fliers as well.

Left to their own devices, rove beetles will live under forest or garden litter. There they eat the litter and hunt for other insects.

They'll hang around dead animals, waiting for their prey, such as flies and maggots.

Rove Beetles in Your Gardens

To attract these beetles to your garden areas, leave an area of the yard unmowed and garden soil untilled. This will attract the beetles and many other helpful insects.

Aleochara bilineata eggs are deposited in the soil among the roots of root maggot-infested plants. Larvae hatch in about 5 to 10 days and actively search for root maggot puparia in the surrounding soil.

Late-season larvae pupate within the host and emerge as adults after 30 to 40 days. The larvae overwinter and emerge in July.

Adults live 40 to 60 days. The life cycle, from egg to adult is about 6 weeks. There may be two generations per year. The second generation emerges at the end of August or in early September.

A. bilineata adults may eat up to five root maggot larvae per day. A pair of adults may destroy 1200 eggs and 130 larvae, and during their lifetime their offspring may parasitize several hundred pupae.

Adults will eat their own eggs and attack other adults when food supplies are low. If you plan to introduce A. bilineata (which has been mass reared for control of root maggots), ensure that they have enough organic matter and insects to eat and enough insects to parasitize. There's no point paying for them if they're going to kill each other.

Before you decide to buy rove beetles, look under debris and rocks, near water, in compost and piles of decaying material, and in sweet corn tassels and silks late in the season.

If you find lots of them, you won't need to buy any next season. But if they seem scarce, it might be a good idea to invest in some early next year.

If this page was valuable for you, please share your new knowledge. Click Like...