Rove beetles are a family of mostly elongated predators that protect your plants against a great many garden pests.
There are over 63,000 different species of rove beetles (Staphylinidae), making them the largest beetle family in the world. There are approximately 4,360 species in the United States. Rove beetles have been around for over 200 million years and it may take another 200 million years to sort out this particular family tree. Currently, there are over 30 subfamilies of rove beetle, and scientists are still trying to sort it out.
However these tiny beetles end up being related, the majority of them pack a wallop when it comes to devouring many common garden pests.
Also known as trash beetles, these beneficial insects are often found in leaf litter, mulch, under loose bark, and around fallen trees. They may also be found in bird nests and rodent burrows where they presumably feed on fly and flea larvae. This huge family is extremely diverse. Some have evolved to live within caves, while others prefer living in mushrooms.
Rove beetle description
As you might expect from a family of this size, rove beetles come in a variety of shapes and sizes. Most of them are very small, averaging only 0.08 to 0.30 inches long, but they can range from 0.03 to 1.5 inches in length.
Most rove beetles have a narrow body that can squeeze into tiny crevices in search of prey and shelter. Rove beetles can be black to brown, yellow to red, and even an iridescent blue-green. They have thread-like antennae with 11 segments; some of them have little knobs at the ends. Most rove beetles have short wing covers (elytra), which means you can see several abdominal segments. Many rove beetles look like a multicolored earwig without its pincers, but certainly not all.
Rove beetle eggs are typically white, but can be spherical, pear-shaped or oval. Flattened larvae may have a distinct ‘neck’ or an armored head, though not all exhibit those characteristics. Pupae can be hard, dark colored cases, or naked white grubs, depending on the species. Adults tend to be long-lived.
Many rove beetle species produce secretions. Some of these secretions help repel water, allowing clumsy insects to recover from falling into water, while other secretions can be particularly toxic. One of those toxic secretions, found in the Paederous group, is transferred from mother to offspring, at birth, providing protection against spiders. This secretion can cause skin irritation and it can damage your eyes. It is the most powerful animal toxin that we know of, but scientists are learning how to use it to heal lesions and treat cancer.
Rove beetle diet
Adult rove beetles eat mites and small insects, as well as root maggot eggs and larvae. Rove beetle larvae also parasitize root maggot larvae. The rove beetle diet is a Who’s Who of garden pests, including:
If eating all those pests weren’t reason enough to appreciate rove beetles, it ends up that adult rove beetles also pollinate cherimoya fruit.
You can help the rove beetles in your garden by avoiding the use of broad-spectrum pesticides and insecticides, and by maintaining permanent areas planted with bunch grasses or other low-growing perennials to provide year-round habitat for these tiny hunters.
What types of rove beetles have you seen in your garden?
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