If you have a farm or a large garden, you may have seen a variety of beetles flying around from time to time. Many of these beetles are not harmful to your plants at all. In fact, they are actually protecting your plants from the harmful insects and pests, which is why they’re referred to as predatory beetles. Encouraging them by providing suitable living conditions is a pest control strategy, often used in organic farming and organic gardening. As with most beneficial insects, there can be negative side effects or consequences associated with too many insects in a given area. But in general, beneficial beetles suppress persistent insect problems.
There are thousands of different kinds of predatory beetles, but there are five specific species that are commonly found in North America. It’s important to know how to identify these beetles and the ways in which they’re helpful to your garden or farm. Once you know a little bit about the five common species, you may realize that you’ve mistaken them for harmful insects in the past and have tried to get rid of them with pesticides or insecticides. You’ll also realize just how valuable predatory beetles can be to you.
Ground beetles are a part of the Carabidae family and while they are extremely common, you may not see a whole lot of them during the day. These predatory beetles are mostly nocturnal. During the day, you’ll find them hiding underneath rocks and logs. Once darkness settles, they come out from their hiding spots and search the surface of the soil for the harmful insects. Ground beetles vary in size and behavior, but they’ll work to rid the soil of insects such as snails, slugs, caterpillars, mites, earthworms and many other types of insects.
Ground beetles are often shiny black in appearance and their wing covers are rigid and grooved. They eat a lot each night, often eating enough to equal or even surpass their own body weight. When they capture their prey, ground beetles regurgitate digestive fluids on the prey to soften them before eating.
Soldier beetles are also called leatherwings and they’re included in the Cantharidae family. There are just under 500 different types of these beetles in North America. Full grown Soldier beetles have wings that are soft and leathery. They fly well and help to pollinate different varieties of flowering plants.
Adolescent Soldier beetles can be found under rocks and logs and in piles of leaves. They mostly feed at night and move very fast, which makes them excellent at catching their prey. They use their big grasping jaws to capture aphids, caterpillars, grasshopper eggs, mealybugs and many other types of insects. Soldier beetles of all ages and sizes protect themselves from other predators by excreting a foul smelling chemical from their bodies.
Tiger beetles are members of the Cicindelidae family. There are over 100 different types of these beetles in North America. Unlike most other insects, these beetles are very pretty and can be found in an array of different patterns and colors such as black, red, purple, shiny blue, iridescent green and bright yellow. Many of them are also black. Their legs are long and thin, which allows them to run at fast speeds. Their bodies are long, and they have wide heads with large eyes.
Adult Tiger beetles have mandibles that are very thin and long. They use their mandibles to catch their prey. Once they have it captured, the beetles spit up digestive enzymes onto their prey, which begins to digest the insects. They then use their mandibles to smash their prey before they eat them. Adolescent Tiger beetles live in burrows in the ground. They hide in the burrows with their heads blocking the openings so they can reach out and grab their prey as it slinks by. They then pull their prey into the burrow and feast on it.
Rove beetles belong to the Staphylinidae family. There are over 3000 different types of beetles in this family. Rove beetles are black or brown and have exposed abdomens and short wing covers. Many types of Rove beetles will curl their abdomens upwards similar to the way a scorpion curls back when it feels threatened. While this act may look menacing, Rove beetles are harmless as they do not have stingers.
These predatory beetles eat insects that are attracted to decaying organic materials. They eat insects such as snails, slugs, ants, root maggots, termites and many others. You will most often find Rove beetles underneath rocks, in the woods, in compost piles, in manure and in plant debris. The fast moving adolescent Rove beetles feed on the same prey by capturing the prey with their jaws.
Lady beetles are also known as Ladybugs. They are among the Coccinellidae family. There are over 450 different types of Ladybugs in North America and most of them are predators of various soft bodied insects. While the most common kinds of Ladybugs are red and black, there are also Ladybugs that are pink, brown, yellow, orange, gray, black and cream colored. Most Ladybugs have spots, but there are some that don’t have any spots at all.
Ladybugs tend to go after insects such as small caterpillars, aphids, whiteflies, insect eggs and pupae, psyllids, mealybugs, scale and mites. During the winter, most Ladybugs hide in tree barks and similar types of natural structures. The kind of Ladybugs that inhabit your home during the winter is generally the introduced multicolored Asian Lady beetles.
Now that you know more about the 5 most common types of predatory beetles in North America and hopefully you will feel a bit more welcoming towards them the next time you see them living in your garden. These beetles are your friends and are just as protective of your plants as you are. They can significantly reduce common insect and weed problems and in some cases eliminate the need for chemical control. For maximum effectiveness, beneficial insects should be released when pest densities are low to medium. Keep in mind that beneficials are not pesticides and they are not a miracle cure. Just as it takes time for pest problems to develop, it also takes time before beneficials can resolve them.