Helpful Beetles

There is a place in nature for all living things, meaning in some way each animal serves some purpose that helps the environment stroll along in some relatively smooth fashion. We humans tend to divide things into groups, though, and with bugs those groups often are pretty cut and dry, and we may offer only two pretty basic categories:

Good Bugs and Bad Bugs

Now, this may be a little harsh of us to judge bugs in this way, but I believe we have every right to manipulate our human environments – our homes and offices – to exclude those bugs that can cause us easily identifiable problems. For example, as wonderful and beneficial as spiders are in their role of eating nasty flies and pesky moths, I’d really rather not have a Black Widow Spider resting in her web above my bed, keeping me free and clear of moths at night. This situation would certainly allow me to classify this Black Widow as a “bad bug”. I’m just a little crazy that way.

However, there are a lot of insects that are pretty clearly “good bugs” too, and I’d like to look at the BEETLES in this article, to help you understand some of those that you may see in and around your home. Without knowing what they are or what they do it is pretty tempting to just smash them and be done with it, but so many of them are harmless to us but helpful to our gardens that the better course of action might be to help them find the door and live on.

Soldier Beetles:

We know the names of some beetles already – June Beetles, for instance – although we many not necessarily recognize one if we saw it. But a lot of the beetles are unknown to us. One of the most common ones that you will find around your home in the spring or summer may be the Soldier Beetle. These colorful beetles often are attracted to lights, and may end up on your front porch. One reason for this is that these are predators – they eat other bugs, and what better place to find a bug-meal than around a porch light, with its nightly gathering of gnats and moths? It sure saves the Soldier Beetle from having to do all the hunting itself if we’ll just serve up the buffet.

Soldier beetles are also called “leatherbacks”, due to the somewhat leathery appearance of their wings, that are soft and gray. They often are yellow with black spots, or gray with orange head and thorax, and usually around an inch long. These helpful beetles are completely harmless to people, unless you try to eat one, and then you might get a nasty taste in your mouth and possibly some blisters on your tongue. The soldier beetle, you see, has some juices in its body that we call “cantharadin”, and this fluid helps keep the beetle from being eaten by its own enemies.

However, as long as you don’t stick it in your mouth you can pick this beetle up, enjoy its colorful appearance, and drop it back outside to feed on the aphids, gnats, or any other small insects it can get its jaws on. Soldier beetles are extremely beneficial.

Ground Beetles:

Another large group of beetles is the Ground Beetles. Now, there are a lot of beetles that crawl around on the ground, but one of the largest families of them is given the scientific name of the Carabidae. Maybe a better name for them would be the “predaceous ground beetles”, because the vast majority of them, and there are around 12,000 different kinds in the United States, eat other insects. Some of the biggest ones are black or even shiny green, and they help us out by feeding on snails.

Most of the common ground beetles you will find are around ½ inch long, and black and shiny. They are somewhat flattened, have long antennae, and run very quickly in their pursuit of other bugs to feed on. Many others, though, could be reddish-orange, yellow with spots, metallic blue, or a variety of combinations. It’s a big and varied family of beetles. It’s probably a good idea not to put any of these in your mouth either, because when they are disturbed they can ooze out some awful smelling (and probably awful tasting) juices, to keep their predators away too. Sometimes we even dub these critters as “stink bugs”, but they aren’t the real Stink Bugs that feed on plants.

Probably the king of the ground beetles, when it comes to deterring animals that think it would be a great dinner, is the Bombardier Beetles. These gray and red beetles can instantly shoot out jets of burning acid when they are disturbed, and any frog, bird, or lizard that puts one in its mouth realizes immediately that it was a bad idea, and will desperately try to get it back OUT of its mouth.

One of the annoying habits of some species of ground beetles is to choose your house as their cubby hole for the winter. It’s not uncommon to find them roaming around on your floor, sometimes by the many thousands, as they look for winter quarters as the weather turns cold outside. The best thing to do, of course, in the interest of a healthy garden, would be to herd them all up and take them back outside. But, they’d probably just run right back in unless you take them a few blocks away.

Lady Bugs:

The proper name for these beetles really is “Lady Bird Beetles”, but I’m not going to try to change years of upbringing and nursery poems now. I mean “lady bird beetle, lady bird beetle, fly away home……” It just doesn’t flow. Without a doubt these are the most recognizable beetles in the country, although there are a great many different kinds, and some of the color forms may be new to you so that you might not recognize one of these as a ladybug when you come across it.

We already have a separate BugInfo article on Ladybugs, so I won’t spend a lot of time here, but these clearly are extremely beneficial to us with their role of eating many kinds of pests of our plants. Both the adults and the larvae are predators, and the larva is almost always a mystery to people when they see it, and I am often asked what the heck the little “alligator-looking” bugs are. These are completely, absolutely harmless to people, and will show up in large numbers on trees that are infested with aphids or scale insects, or on other plants that may have these nasty, sap-sucking parasites harming them.

Aquatic Beetles:

Another neat group of beetles is composed of three or four families of beetles that live in water most of their lives. I say “most of their lives” because many of them have the habit of leaving the water and flying around, sometimes ending up in your backyard pool and other times just landing on the ground where you may find them flopping around in a clumsy way. Since they are adapted to life in the water their legs and bodies are designed for swimming, not walking, and on land they don’t do so well.

One of the ones you might have seen on ponds or quiet creeks is the Whirligig Beetles. These small beetles can be seen in groups of a half dozen or so, spinning around in circles on top of the water. Two other families of beetles live underwater – the Predaceous Diving Beetles and the Water Scavenger Beetles. The members of all three of these families eat other insects in the water, and these often are bugs such as the larvae of mosquitoes, so more power to them.

You will encounter these beetles though, and we also have a neat little article entitled “Bugs in the Pool” that will enlighten you further on them, and why they go to all the trouble of flying into your swimming pool when life is so much better in the local creek.

So, there you have it, some of the common kinds of beneficial beetles that you are likely to encounter in your yard or your home. Of course, there are a lot of other beetles that benefit us by their activities as decomposers, recycling dead trees or dead animals. But, these we talked about in this article are predators, and we appreciate their work.

There is one more family of beetles that I’d like to mention, even though you probably aren’t going to see the beetles in your yard. However, these aggressive predators deserve mention for two reasons. First, they often are beautiful colors – metallic green or blue or a mix of colors. Second, the way they feed is pretty impressive, and this group of beetles is known, appropriately, as the Tiger Beetles. There are dozens of beautiful species in North America, and some even gaudier ones in some of the tropical countries.

The adults can be found along sandy beaches or other damp areas, where they fly up the moment you get near them, and land again a few feet away. They run very quickly, making it easier for the adults to catch food. The larvae, however, lay in wait in a hole in the ground, a tube they have dug for themselves. When they detect the vibration of an insect walking past the entrance to their hole they lunge out and snatch the insect with their massive, sickle-like jaws, and then drag the prey back into the tunnel to eat it.

Makes you a little glad they are only one inch long.