Are Grapevine Beetles Harmful to Humans? Uncovering the Truth

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Grapevine Beetle

What Are Grapevine Beetles

Identification and Characteristics

Grapevine beetles (Pelidnota punctata) are a type of scarab beetle. They are also known as the spotted June beetle, which belongs to the Scarabaeidae family. They can be found in eastern Canada and some parts of the United States.

These beetles are recognizable by their distinct coloration and physical features:

  • Size: Approximately 1 inch in length
  • Coloration: Off-yellow to light brown with black spots
  • Body: Sturdy and oval-shaped
  • Wings: Covered by a hard shell called elytra
  • Antennae: Serrated and fan-like
  • Mandibles: Strong and developed

Life Cycle

The life cycle of the grapevine beetle consists of four stages: egg, larva, pupa, and adult. The development process is as follows:

  1. Egg: Female beetles deposit eggs in the soil near the base of suitable host plants.
  2. Larva: The larvae, or grubs, feed on decaying wood and plant material. They grow underground and can stay in this stage for up to two years.
  3. Pupa: The mature larvae pupate in earthen cells within the soil.
  4. Adult: After approximately 3 to 4 weeks, adult beetles emerge from the pupal stage.

While grapevine beetles primarily feed on grapevines, they do not pose any serious threat to humans.

 

Grapevine Beetle

 

Grapevine Beetle Interaction With Humans

Biting and Human Safety

Grapevine beetles (Pelidnota punctata) are not harmful to humans. They are not known for biting or displaying any aggressive behavior towards people.

In fact, grapevine beetles are part of the scarab beetle family, which is generally considered harmless to humans. As such, you do not need to worry about your safety when encountering these beetles.

Damage to Gardens and Vineyards

Grapevine beetles can cause damage to gardens and vineyards, but the extent of the harm is relatively mild. Their primary target is the foliage of grapevines, as their name suggests.

However, they can occasionally feed on the leaves of other plants as well. A few key points to note about grapevine beetles in gardens and vineyards include:

  • They primarily feed at night
  • They are most active in the late summer
  • The damage is often cosmetic rather than fatal to the plants

In a comparison of the potential damage caused by grapevine beetles versus other pests, these beetles are relatively benign.

Other pests, such as Japanese beetles, can cause considerably more harm to plants, including severe defoliation and even the death of the plants.

 

Grapevine Beetle

 

Pest Potential Harm to Plants
Grapevine Beetle Cosmetic damage (mostly)
Japanese Beetle Severe defoliation/death of plants

Diet and Habitat

Host Plants and Foliage

Grapevine Beetles are known for their attraction to grapevine leaves and other types of foliage. While their diet also consists of other sources like tree sap, some examples of their preferred host plants include:

  • Grapevines
  • Maple trees
  • Deciduous trees

Nocturnal Behavior and Tree Stumps

These beetles exhibit nocturnal behavior, making them more active during the night. They tend to hide in tree stumps and soil during daylight hours. Here are some characteristics of their habitat:

  • Woodlands
  • Thickets
  • Vineyards
  • Deciduous forests

While Grapevine Beetles may be a nuisance to some plants, they pose no harm to humans. The table below compares some of their features to further illustrate this fact:

Feature Grapevine Beetles Harmful to Humans?
Diet Foliage, Tree Sap No
Habitat Woodlands, Vines No
Activity Period Nocturnal No

Natural Enemies and Control Methods

Predators and Beneficial Insects

Grapevine beetles have natural enemies that help keep their population in check. Some of these predators include:

  • Birds: Many bird species consume beetles and their larvae as a food source.
  • Lacewings: These insects prey upon beetle larvae and other small pests.
  • Dung Beetles: While not directly feeding on grapevine beetles, they help in breaking down and recycling organic matter, benefiting the soil ecosystem.
  • Beneficial nematodes: These microscopic worms attack and kill beetle larvae in the soil.

Insecticides and Chemical Control

In situations where grapevine beetle populations are high, chemical control may be necessary. Some common insecticides used for beetle control include:

  • Pyrethrin: A natural insecticide derived from chrysanthemum flowers.
  • Spinosad: A naturally occurring soil bacterium used as an insecticide.
  • Insecticidal soap spray: A less toxic option for controlling soft-bodied pests like larvae.

Grapevine Beetle

 

Insecticide Pros Cons
Pyrethrin Natural, effective against adult beetles Short residual, toxic to bees
Spinosad Low toxicity to humans, long-lasting Harmful to some beneficial insects
Insecticidal soap Safe for humans, pets, and plants Less effective against adult beetles

Organic Control Measures

For an organic approach to grapevine beetle control, these techniques can be considered:

  • Neem oil: A natural pesticide extracted from the seeds of the neem tree.
  • Diatomaceous earth: A powdery substance made from fossilized aquatic organisms that kill insects by damaging their exoskeletons.
  • Sticky traps: Used to monitor and trap adult beetles.
  • Organic gardening practices: Cultivating a diverse garden with plants that attract beneficial insects and predators.

Examples of organic control measures:

  • Applying neem oil or diatomaceous earth to the soil and plants to deter beetles.
  • Placing sticky traps near grapevines to catch and monitor adult beetles.
  • Planting various flowers, such as marigolds or sunflowers, to attract predators of beetles.

Bug Control Recommendation Tool

What type of pest are you dealing with?

How severe is the infestation?

Do you require child/pet/garden safe treatments (organic)?

Are you willing to monitor and maintain the treatment yourself?


Comparison to Similar Insects

Japanese Beetles and Their Impact

Japanese beetles are invasive insects that can be harmful to various plants. They feed on the leaves of numerous plants, causing them to appear skeletonized1. However, they are not harmful to humans.

Characteristics of Japanese Beetles:

  • Metallic green and copper color
  • About ½ inch long
  • Feed on plants in their adult stage

Other Beetle Species

There are numerous other beetle species that exhibit varying levels of impact on plants and humans. Here, we examine a few examples.

Weevils

Weevils are small beetles that can cause damage to stored grains and seeds. They typically do not directly impact humans2.

 

Acorn Weevil

 

Stag Beetles

Stag beetles are characterized by their large, pincer-like mandibles. These beetles are not considered harmful to humans, and their larvae feed on decomposing wood, often found in gardens.

Flea Beetles

Flea beetles are small and can jump like fleas when disturbed. They cause damage to various plants by feeding on the leaves, creating small holes4. They do not pose a threat to humans.

Blister Beetles

Blister beetles are so named because their body fluids can cause skin irritation, including blistering. They can be harmful to humans if mishandled.

 

Black Blister Beetle

 

Ground Beetles

Ground beetles are generally not harmful to humans, and can even be helpful as they feed on pests like slugs and caterpillars6.

Rhinoceros Beetles

Rhinoceros beetles are large and uniquely shaped, with a horn-like structure on their heads. They feed on plant material and don’t pose any significant threat to humans7.

 

Rhinoceros Beetle

 

Comparison Table

Beetle Species Impact on Plants Harmful to Humans
Japanese Beetles Significant No
Weevils Moderate No
Stag Beetles Minimal No
Flea Beetles Moderate No
Blister Beetles Moderate Yes
Ground Beetles Minimal No
Rhinoceros Beetles Minimal No

Additional Grapevine Beetle Information

Lifespan and Reproduction

The lifespan of a Grapevine Beetle is typically around one year, from egg to adult. During their short life cycle, they go through several developmental stages:

  1. Eggs: Female beetles lay eggs after mating, usually on decaying wood and leaf litter.
  2. Larvae: The eggs hatch into white larvae (grubs) that feed on rotting wood.
  3. Pupae: After growing and shedding their exoskeleton multiple times, the larvae pupate.
  4. Adults: Finally, the pupae transform into adult beetles, ready to mate and begin the cycle again.

Characteristics of the Grapevine Beetle Lifecycle:

  • The development from egg to adult typically takes less than a year
  • Eggs laid on rotting wood or leaf litter
  • Grubs feed on rotten wood, while adults feed on deciduous plants

Grapevine Beetles don’t generally harm humans, but if you are growing apple trees or grapevines, it’s essential to monitor their presence and any potential damage they may cause to these fruit-bearing plants.

The proactive approach includes checking for black spots on leaves, rotten wood, and decaying portions of the plants to address infestations as soon as they appear.

 

Grapevine Beetle (image lightened)

 

Conclusion

Since grapevine beetles are usually found in gardens and vineyards, people often consider them harmful.


However, these distinctive insects, with their eye-catching appearance and habits, do not pose a direct threat to people. These insects feed on plant foliage, and grapevine beetles focus on vegetation and refrain from harming humans.


Yes, they can cause damage to plants, but it is nothing too drastic. However, you can use the tips and tricks mentioned in the article to get rid of them.


Understanding their characteristics, habits, and role in ecosystems can help us appreciate these beetles without undue worry about personal harm.

Grapevine Beetle

 

 

Grapevine Beetle

Grapevine Beetle

Authors

  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

    View all posts
  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

    View all posts
Tags: Grapevine Beetle

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14 Comments. Leave new

  • I think I’ve just found two of these beetles at the edge of our drive. We do actually have some wild grapevines within 50feet. We live in southern Dutchess County, NY

    Reply
  • Do these beetles bite or are they harmful in anyway??

    Reply
  • I’m sorry to be more specific. I live in florida and have a 98 yr old grandfather that likes to sit on the front porch a lot but we have this big beigeish colores beetle that looks like the grapevine beetles but has no spots on it its just a nice beige color and looks really smooth expect for his legs, they clawish or prickly. this beetle has been on our porch for the past week day and night. and since I’ve never seen one before and after googling beetles and learning some bite I’m concerned because at my grandpas age and condition I don’t think he could handle getting bit by anything harmful. I’ve gotten it in a bowl before and moved it to the grass and it keeps comming back.is this a kind of beetle we should be careful of??

    Reply
  • Just found one in the strawberries. I do have grapes so I an wondering if I should take some action. please reply if you know about something I should do about it.

    Reply
  • Just had one visit me here in Grand Rapids, Michigan! I snapped a photo of it because I was curious as to what finally landed on my outdoor multi-color chili lights. It was making all sorts of buzzing noises trying to land as it was running into things. Beautiful beetle!!! Grand Rapids is about 30 miles inland from Lake Michigan in the southwest portion of the lower peninsula.

    Reply
  • Debbie Belcher
    June 28, 2016 7:41 pm

    I found one of these beetles in my kitchen..we live in Western Grove, AR. It was a very hard shell.

    Reply
  • I found one in Michigan in a family members house.

    Reply
  • Wanda Taylor
    July 13, 2020 8:11 pm

    We were in bed watching the news when suddenly this huge bug flew around the TV then seemingly disappeared! Scared me almost to death. I ran to get the flyswatter while my husband looked for the bug. Suddenly, he spotted it on his pillow & whacked it hard then picked it up with tissues. As he was unraveling the tissues, we realized just how hard it’s shell was. Also, it’s legs began to move! At that point he took it away & death came to that particular beetle. I said, “Actually, it was kind of pretty”. All my husband said was, “Aren’t you glad it wasn’t a spider!”
    I am 81 & he is 88. We live in central IN & neither of us had ever seen that kind (grapevine beetle) beetle before.

    Reply
  • I just saw one. He seems to be sleeping in my Virginia Creeper that is growing on the lattice part of my deck. I’m just leaving him there. Today is one of the most humid days I can remember for Toronto, Ontario. We have been having a heatwave so maybe that’s why he’s visiting.

    Reply
  • I found one in densely growing English ivy around my house in suburban Detroit.

    Reply
  • I have a little office setup in the garage and I heard this thump in front of me, shortly after that I saw the biggest flying bettle I’ve ever seen in my life. Are you kidding me?… where in the hello he’s heading this way did these come from?… There he was just walking around in my desk drawer like he was deciding where he was going to put his stuff. The nerve of this guy. It was just about then he decided to demonstrate his flying skills. While I was manuvering to a more strategic postion to secure the house door, I lost sight of him. At this time I am reasonably secure in knowing that he was unable to enter my domain. I’m not sure if we feel the same way about this bug.

    Regards,

    Scrd Shtless

    Reply
  • 8/26/22: I found a dark object on the carpet in my family room.When I went to study it closer, I realized it was a lovely light orange beetle lying on its back.It was shiny with 2 dots on each side of its body.It was deceased. I immediately sought information about it. I learned it is a Grapevine Beetle. My husband had been clearing vines off a wooden fence.Did it hook a ride on my husband or our dog and make its entry into the house? I am keeping it so I can show my grandchildren when I next see them.

    Reply

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