Predatory Beetles : Rove beetles

categories: Natural Enemies Predatory Beetles

revision date: 2022-10-25 09:45

Close-up of adult rove beetle.
Adult rove beetle (Staphylinidae)
Photo by: D.G. James

Biology

Rove beetles are odd-looking shiny brown or black beetles, ¼- 1 inch in length, elongate and short-winged. Turn over a rock or log especially near a compost pile and you will frequently find these fast-moving beetles. They look ‘fierce’ because of the scorpion-like way they hold the tip of the abdomen in the air, but most are only dangerous to the insects on which they feed. Rove beetles have long sharp mandibles that close sideways across the front of the head and larger species are capable of inflicting a bite if roughly handled. Adults and larvae feed on a wide range of insects smaller than themselves, especially fly maggots, ant larvae, mites and many other soft-bodied arthropods. Rove beetles are common on the ground in most gardens but are rarely seen because of their nocturnal and secretive behavior.

Prey or Pest Targeted

  • Mites, aphids, leafhoppers, mealybugs, thrips, insect eggs and small larvae, scale insects, whiteflies

Attracting and Keeping Natural Enemies and Pollinators in Your Yard and Garden

  • Avoid regular use of synthetic, broad-spectrum pesticides. Infrequent use of certain narrow-spectrum pesticides is more compatible with some beneficials but generally the less chemical inputs there are, the greater and more diverse the beneficial insect community will be. Extensive lawns are also not conducive to attracting and retaining a diversity of beneficial insects, mites and spiders. Minimize lawn areas and maximize shrub and bush plantings. Many beneficials reside naturally in riparian and other ‘natural’ areas near to many back yards. Natural dispersion from these refuges ensures that some beneficials will visit back yards but they will not stay unless food, host and shelter resources are available. Native plants have closer affinities with native insects and therefore provide most of these resources. A garden with a good diversity of local native flora in and around back yards, will improve the abundance and diversity of local, beneficial arthropods. Native flora also provides natural overwintering sites for many beneficial insects and it is useful to leave at least a small area of native vegetation undisturbed during fall and winter.
  • Some kinds of beneficial insects (e.g. lady beetles, lacewings, predatory mites) are available for purchase from commercial suppliers. However, benefits from introducing these beneficials are usually limited and short-lived. Upon release, commercially obtained lady beetles and lacewings often disperse and may rapidly leave your backyard despite the presence of prey and suitable nectar resources. Generally, it is more effective and sustainable to create a garden habitat that will be colonized by beneficials naturally.