Grapevine beetles are large orange or tan bugs that like to feed on grapevines and fruit trees. Though they are big and scary looking, they aren’t usually a major garden pest.
In this guide you’ll learn all you need to know about them. I’ll go through everything from what they eat, their life cycle, where they come from, the damage they cause, and whether you should worry about getting rid of them or not.
Plus you’ll find lots of easy and non-toxic ways to prevent grapevine beetles 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 sometimes called a ‘spotted June beetle’. Like their more common relative, they’re nocturnal and attracted to bright light.
What Do They Look Like?
First off, they’re hard to miss because they are HUGE. They’re easily two-three times larger than a Junebug, and actually kind of scary looking the first time you see one. YIKES!
If their size isn’t 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.
But don’t let this fool you, they can still move pretty darn fast. Their size and clumsy way of travel makes them easy to spot when they’re buzzing around.
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 white grub worms that burrow deep into the ground, where they overwinter until spring. As the soil warms up, 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 adult beetles sometime in July. There’s only one generation per year.
What Do They Eat?
As their name suggests, these beetles like to 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 pretty uncommon.
The larvae eat rotting organic material, so they are actually considered beneficial. Thankfully, the larvae do not feed on plants. Only the adults do that.
Damage To Plants
They can damage plants by eating holes in the leaves or fruits. They will skeletonize the leaves, and can also destroy the fruit.
However it’s very rare for them to cause major damage to the plant. This is because they aren’t usually found in large numbers.
What’s Eating My Grapevine Leaves?
Just because you find damage on your plants doesn’t mean you have grapevine beetles. The more likely culprit is Japanese beetles.
Those pesky bugs absolutely love my grapevines, and feast on them every summer. They ARE major garden pests, and like to congregate in large numbers. But they’re much smaller and iridescent green and brown. Read all about how to identify and control Japanese beetles here.
Are Grapevine Beetles Harmful?
Luckily they are not harmful to humans or pets, and they don’t sting or bite. They are also rarely harmful to plants.
Even though the adult beetles primarily feed on grapevines, they aren’t considered major pests in vineyards. So it’s highly unlikely they would cause major problems in your home garden.
A major infestation certainly could cause damage, but it’s pretty uncommon. So don’t worry if you see one or two of them flying around your neighborhood.
How To Get Rid Of Grapevine Beetles Naturally
In the unlikely event that you do have an 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). So please use the organic control methods below to target only the pest insect.
Related Post: How To Control Garden Pests Naturally
Hand Picking
Since they are so big, 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 early morning to hand pick them when they are still out, but not as active.
Diatomaceous Earth
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 grapevine beetles. It will get under their shell and cut up their soft bodies, eventually killing them.
Insecticidal Soap Spray
An organic insecticidal soap spray can work to shock them so they’re easier to pick from the plant. You can mix your own using 1 teaspoon of mild liquid soap to 1 liter of water.
You have to spray it directly on the bugs though, or it won’t have any effect. Also, it probably won’t kill them right away, so use it to stun them before hand-picking.
Beneficial Nematodes
Another organic method you can try is beneficial nematodes. These are tiny predatory parasites that live in the soil and feed on the larvae (grub worms).
For best results, apply them in the fall or spring when the grubs are close to the soil surface. Read all about how to apply beneficial nematodes here.
Milky Spores
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.
Related Post: Natural Garden Pest Control Remedies And Recipes
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 cover your plants during grapevine beetle season (mid-summer through fall). This works great for keeping all types of pests away.
Use a lightweight garden fabric or tulle to cover or loosely wrap the vines. Get the exact steps for how to protect your grapevines here.
Keep Your Garden Clean
The adult females tend to lay their eggs on pieces of rotting wood. So, if you have any dead wood sitting around your garden or property, clean it up.
That will help to prevent the adult beetles from laying their eggs close to your grapevines, and hopefully they’ll go elsewhere.
FAQs
No, grapevine beetles are not poisonous. They do not emit or contain any type of toxins, so you have nothing to worry about there.
No, grapevine beetles do not bite or sting humans or pets. They just eat plants and fruit.
No, grapevine beetles are not dangerous. Though the adults do feed on foliage and fruit, they rarely cause major damage or kill the plant.
Their life cycle, from egg through adult, is two years. But the adults only live for one season. They lay their eggs in the fall and the larvae overwinter underground.
You probably don’t need to do anything to get rid of them. They are not a major pest or much of a threat to home gardens. So if you only see one or two, then just leave them alone.
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
John Lindsay Morash says
Hello never experienced that grape Beatle what month during the summer or fall do they stop
Amy Andrychowicz says
Grapevine beetles will stop once it gets cold in the fall, usually around the first hard freeze.