Grapevine beetles are huge and scary looking, but they aren’t usually a major pest. In this post, you’ll learn all about what they eat, their life cycle, where they come from, the damage they cause, and if you should worry about grapevine beetles in your garden or not.
While not a major pest for commercial crops or home growers, these large tan beetles can be intimidating, and cause alarm for new gardeners.
In this guide, I’ll go through how to identify grapevine beetles in your garden, and determine whether you need to get rid of them or not.
You’ll learn all you need to know about the grapevine beetle. Plus find lots of easy and non-toxic ways to prevent these critters from eating your plants, if they ever do become a pest in your garden.
What Is A Grapevine Beetle?
The grapevine beetle (Pelidnota punctata), is a type of scarab that is found in eastern and central parts of North America.
They are related to the Junebug, and are sometimes called a spotted June beetle. Like their common relative, the Pelidnota punctata is nocturnal, and attracted to bright light.
What Do They Look Like?
First off, these beetles are hard to miss; they are HUGE. They’re two-three times the size of a Junebug, and actually kind of scary looking the first time you see one. YIKES!
If that’s not enough to make a positive ID, then look for other distinguishing characteristics. The colors range from bright orange to light tan, and they usually have black spots on their back (though some may not have spots).
They fly around at night, and are just as clumsy as their more popular relative. If you ask me, they look like they’ve been drinking when they fly.
Their size and clumsy way of travel makes grapevine beetles easy to spot when they’re buzzing around. But don’t let this fool you, they can still move pretty darn fast.
The Grapevine Beetle Life Cycle
There are four stages to the grapevine beetle life cycle: adult, egg, larva, and pupa. The adults lay their eggs in the soil, and the larvae hatch a few weeks later.
The larvae are large grub worms that burrow deep into the ground, where they overwinter until spring. In the spring, they slowly make their way back to the surface, where they feed on rotting wood.
Once they’re mature enough, the grubs pupate near the surface of the soil, and they emerge as beetles sometime in July. There’s only one generation per year.
What Do Grapevine Beetles Eat?
As their name suggests, they eat the leaves and fruits on both wild and cultivated grapevines. They can feed on other types of fruits too (like apples and raspberries), but it’s very uncommon.
The larvae eat rotting organic material, so they are considered beneficial. Thankfully, the larvae do not feed on grapevines. Only the adults do that.
Damage To Plants
Grapevine beetles damage plants by eating holes in the leaves or fruits. They will skeletonize the leaves, and can also destroy the fruit.
However it is very rare for them to cause major damage to the plant, because they aren’t usually found in large numbers.
What’s Eating My Grapevine Leaves Then?
If it’s not the grapevine beetle, then what is destroying your grapevines? Well, if I had to guess, I would say it’s probably Japanese beetles.
They absolutely love my grapevines, and feast on them every summer. Those ARE major garden pests, and are also found in large numbers. Read all about how to identify and control Japanese beetles here.
Are Grapevine Beetles Harmful?
Grapevine beetles are not harmful to humans or pests, and they don’t sting or bite. They are also very rarely harmful to plants.
Even though the adults primarily feed on grapevines, they aren’t considered major pests in vineyards. So they are very unlikely to cause major harm in a home garden.
A large infestation certainly could cause damage, but it’s pretty uncommon. Seeing one or two grapevine beetles in the neighborhood is not a cause for a concern.
How To Get Rid Of Grapevine Beetles Naturally
In the unlikely event that you do have a grapevine beetle infestation, there are a few different things you can do to control them. But if you only see a couple of them, I encourage you to just leave them be.
There is no reason to ever use synthetic pesticides (plus I’m guessing you don’t want to spray chemicals on your grapes anyway).
Pesticides will kill all types of bugs, including butterflies, bees and many other beneficials. So please use these organic control methods to target only the pest insect.
Organic Grapevine Beetle Control Methods
There are several organic methods you can use to control, or even get rid of grapevine beetles. Try a couple of these to see which works best for you, or combine a few for even better success.
Related Post: Natural Garden Pest Control Remedies And Recipes
Since they are so huge, it’s easy to hand pick them from the plant, and drop them into a bucket of soapy water. I find that Dr. Bronner’s liquid soap works very fast to kill bugs.
But, since they are nocturnal, it may be hard to find them. So I recommend going out in the late evening or very early morning to hand pick them when they are still out, but not as active.
If hand picking them is just too much to bear (and I don’t blame you for that!), then you can try a more hands-off approach.
Diatomaceous earth (DE) is an all natural product made from crushed up hard-shelled organisms. Sprinkle it directly on the beetles. It will get under their shell and cut up their soft bodies, eventually killing them.
Insecticidal Soap Spray
You have to spray it directly on them, or it won’t have any effect. Insecticidal soap may not kill them though, so use it to stun them before hand-picking.
Another natural way to get rid of grapevine beetles is to use beneficial nematodes. These are tiny predatory parasites that live in the soil and feed on grub worms (their larvae).
For best results, apply the nematodes in the fall or spring when the grubs are close to the soil surface. Read all about how to apply beneficial nematodes here.
Harmless to beneficial bugs, milky spore is a naturally occurring bacteria that infects the grubs when they eat it, and eventually kills them.
The downfall is that it can take 2-3 years for this method to be effective. But once active, milky spores last in the soil for several years.
How To Prevent Grapevine Beetles
Rather than treating for them, you could try preventing grapevine beetles from munching on your vines in the first place. Here are a few preventive methods you can try…
Cover Your Vines
Since grapes don’t need to be pollinated by bees, you can keep them covered during grapevine beetle season. This works great to keep the would-be pests off of your vines.
Keep Your Garden Clean
Adult grapevine beetles tend to lay their eggs on pieces of rotting wood. So, if you have any laying around your garden or property, clean it up.
That will help to prevent the adult beetle from laying her eggs close to your grapevines, and hopefully she’ll go elsewhere.
In this section, I’ll answer some of the most frequently asked questions about grapevine beetles. If you can’t find an answer to yours here, then ask it in the comments below.
Are grapevine beetles poisonous?
No. Grapevine beetles do not emit or contain any type of poison, so nothing to worry about there.
Do grapevine beetles bite?
No, grapevine beetles do not bite humans or pets. They just eat plants and fruit.
Are grapevine beetles dangerous?
No, grapevine beetles are not dangerous. Though they do feed on grapevine leaves and fruit, they rarely cause major damage or kill the plant.
How long do grapevine beetles live?
The full grapevine beetle life cycle, from egg through adult, is two years.
How do I get rid of grapevine beetles?
Normally I would say “see the list above to learn how to get rid of grapevine beetles”. But since they are not a major pest, or a huge threat to home gardens, you probably won’t need to do anything.
While they might be intimidating to look at, grapevine beetles are a low priority when it comes to garden pest control. Fortunately, they are easy to deal with when they do become a problem, and there are plenty of choices for keeping the population down.
More Garden Pest Control Posts
- How To Control Flea Beetles In The Organic Garden
- How To Get Rid Of Cabbage Worms Organically
- How to Control Squash Bugs Organically
- How To Get Rid Of Slugs In The Garden Naturally
Share your grapevine beetle stories or experiences in the comments below.
Photo Credit: Public Domain Pictures