June beetles are a common sight in North America during the warm summer months.
With their distinctive metallic green color and buzzing flight pattern, they often capture the attention of gardeners and nature enthusiasts alike.
The outer edges of the body exhibit colors ranging from bronze to yellow, while the wing covers occasionally take on a reddish-brown tint.
But the question arises, are they harmful?
The answer to this question largely depends on the stage of a June beetle’s life cycle. In this article, we are going to explore this impact in details.
Are June Beetles Harmful?
Adult June beetles, such as the Green June Beetle, are typically harmless and feed on fruits, nectar, and foliage.
They may cause minor damage to plants, but are generally considered non-threatening to gardeners. However, adults may inflict your ornamental plants with foliar damage.
However, it’s the June beetle larvae, also known as white grubs, that can cause considerable damage to the roots of grass, broadleaf weeds, trees, and shrubs.
In some cases, these grubs require 2 or 3 years in the soil to fully develop, gradually causing more extensive harm to plants as they grow.
To keep your plants healthy and free from damage, it’s essential to stay vigilant and manage such pests effectively.
June Beetles: Life Cycle, Species, and Habitat
Life Cycle
June beetles complete their life cycle in 2-3 years2. The different stages of their life cycle include:
- Eggs: Female beetles lay eggs in the soil.
- Larvae (grubs): Feed on roots; grow from 1/4 inch to 2 inches long1.
- Pupae: Brown and 1/2 inch long1.
- Adults: Metallic green or brown; nearly 1 inch long1.
June Beetle Species
Some common June beetle species include:
- Green June Beetle (Cotinus nitida)1
- May Beetle (Phyllophaga spp.)3
- May Bug (European Chafer, Amphimallon solstitiale)
Geographical Distribution
June beetles are commonly found in:
- North America1
- Europe (May Bug)
They are attracted to light and have six legs3. June beetles can be a food source for birds and other animals.
However, their larvae/grubs can damage plant roots2. They can be a nuisance for gardeners and homeowners
Comparison Table: Green June Beetle vs. May Beetle
| Feature | Green June Beetle | May Beetle |
|---|---|---|
| Adult color | Metallic green with bronze edges | Light tan to reddish-brown |
| Larval appearance | Cream-colored | Cream-colored |
| Time to complete life cycle | 2-3 years | 2-3 years |
The Harmful Impact of June Beetles
Damage to Plants and Gardens
June beetles can cause significant damage to plants and gardens. They feed on the leaves of various plants, such as roses and other flowers. This can lead to:
- Stunted plant growth
- Reduced flowering
- Increased susceptibility to diseases
Effects on Lawns and Yards
June beetles also impact turfgrass, commonly found in lawns and yards. Their grubs feed on the roots of grasses, which can cause:
- Patches of dying or dead grass
- Loose turf that is easily pulled up
- Uneven lawn surfaces
A well-manicured lawn might suddenly show signs of infestation, such as brown patches or dead grass due to June beetle infestation.
Underground Impact
The underground impact of June beetles is mainly caused by their larvae, or grubs. These grubs feed on various plant roots and can cause significant soil issues, such as:
- Compromised soil structure
- Decreased nutrient availability for plants
- Increased erosion risk
Grubs can grow up to 2 inches long, making them quite damaging to plant roots and soil.
Impact on Trees and Shrubs
June beetles may be particularly harmful to trees and shrubs in gardens and landscapes. They can cause:
- Defoliation of leaves
- Weakened branches
- Slow tree and shrub growth
Crops like corn may also suffer from June beetle infestations, and their feeding can lead to crop loss or poor yield.
Examples of Damage Caused by June Beetles
| Area of Impact | Examples of Damage |
|---|---|
| Plants | Stunted growth, reduced flowering |
| Lawns | Dead grass, loosened turf |
| Soil | Compromised nutrient availability |
| Trees & Shrubs | Defoliation, weakened tree structure |
While June beetles can be quite damaging, understanding their impact on various aspects of gardens and landscapes can help in their monitoring and control.
How to Manage June Beetle Infestations?
Cultural Controls
- Hand-picking: Remove adult beetles and larvae by hand, especially during dusk when they are most active1.
- Trapping: Attract beetles with light traps or fruit-based traps2. Dispose of trapped beetles daily.
Biological Controls
- Predators: Birds, toads, snakes, moles, and skunks can help control beetle populations by feeding on larvae and adult beetles4.
- Nematodes: Introduce beneficial nematodes (Heterorhabditis bacteriophora) to target the white grub stage of the life cycle5.
Chemical Controls
- Insecticides: Apply insecticides with active ingredients such as carbaryl or trichlorfon when grubs are feeding3.
- Preventatives: Use products containing imidacloprid or halofenozide to prevent beetle infestations6.
June beetle control measures
| Method | Pros | Cons |
|---|---|---|
| Cultural | Non-toxic, minimal environmental impact | Can be labor-intensive |
| Biological | Natural, minimal chemical use | Slow-acting, predators can be unreliable |
| Chemical | Fast-acting, effective | Can harm non-target organisms, potential health risks |
Note: Always consider the potential impact on pets and human health before using chemical controls.
Prevention Strategies and Tips
Lawn Care
A healthy, well-tended lawn can resist June beetles and their larvae. Follow these guidelines to ensure better lawn care:
- Regularly water your lawn, especially during dry spells.
- Mow at the appropriate height for your grass type to promote healthy growth.
- Fertilize with the right nutrients and amounts for your turfgrass species.
Garden Maintenance
Prevent damage to your plants by following these steps:
- Regularly inspect plants for beetles and their larvae, removing them by hand if necessary.
- Keep your garden free of debris, which can provide shelter for beetles.
- Plant beetle-resistant plants with strong odors like marigolds and garlic
Monitoring and Trapping Methods
To monitor and trap June bugs, consider these methods:
- Commercial beetle traps can be used to control adult beetles.
- Hand-pick beetles off plants and drop them into a bucket of soapy water.
- Make a homemade June bug trap with molasses and water.
June beetle trapping methods
| Method | Pros | Cons |
|---|---|---|
| Commercial beetle traps | Effective, easy to use | Can be expensive, may attract more beetles |
| Hand-picking | Chemical-free, inexpensive | Time-consuming, not suitable for large areas |
| Homemade June bug trap with molasses and water | Inexpensive, eco-friendly | Less effective than commercial traps |
Remember to always practice moderation when using pesticides, as excessive use can harm your garden’s health and the environment.
Organic options like milky spore can also help control grub populations.
Bug Control Recommendation Tool
Conclusion
While June beetles look captivating with their metallic green color during North America’s warm summer months, their impact on gardens and landscapes is not to be underestimated.
Adult beetles primarily feed harmlessly on fruits, nectar, and foliage. However, it’s the white grubs, the beetle larvae, that can cause extensive damage to plant roots and soil health.
Vigilance, along with a balanced approach of cultural, biological, and chemical controls, proves essential in maintaining healthy plants and landscapes, ultimately mitigating the potential harmful effects of June Beetles.
Footnotes
11 Comments. Leave new
As often happens, I don’t know the species, but I can declare that this one would look quite tasty to much of the world, especially in Asia. Species in Melolonthinae are enjoyed in many parts of the world; the great Vincent Holt wrote about them in his landmark 1885 book “Why Not Eat Insects?”
There’s also some fascinating documentation of grubs and eggs harvested in Indiana in the early 1900s and served to the leadership of the Department of Agriculture. I can provide the text if anyone’s interested. Alternately, I’d love to find out how to harvest these insects efficiently.
Dave
http://www.smallstockfoods.com
Given that Holt, way back in 1885, wrote about the edibility of cockchafers, which are quite similar to this specimen, I’d definitely consider this an amusing appetizer were I in the right mood.
Scarabidae can be eaten in all the phases of their life-cycle.
Dave
http://www.smallstockfoods.com
This posting has now been tagged as an edible insect. Do the Ten Lined June Beetles taste like pine?
I live in east Vancouver and for the last few nights at dusk there are bugs that are buzzing around my front porch and outside in all the trees that line the street. They look to be the size of a small bumble bee and they make a buzzing sound. I’m almost certain that they are not bumble bees but can’t figure out what they may be. Any thoughts to what they might be?
Do you help people identify bug nest? I have one that I don’t enemy know where to start researching.
This same beetle showed up on our front porch in Washington today
My son just found one sleeping on our porch with
a pile of lil moths early this morning! I’ve never seen a junebug before so we went down the google rabbit hole! We’re in eastern washington. Though the same as this image otherwise, it doesn’t have the hand-tennas. Must be female?
yes, females have smaller antennae.
My son just found one sleeping on our porch with
a pile of lil moths early this morning! I’ve never seen a junebug before so we went down the google rabbit hole! We’re in eastern washington. Though the same as this image otherwise, it doesn’t have the hand-tennas. Must be female?
Hello! I am developing a life cycle diagram to support a status assessment for the U.S. Fish and Wildlife Service for Casey’s June beetle (Dinacoma caseyi). I would like to ask your permission to use the Scarab beetle pupae from this page, potential red june beetle from Arizona. We have not observed D. caseyi pupae and the figure would indicate that this is a generalized scarb pupae. I appreciate your consideration. Please reach out if you have questions. Thank you!
Just saw one in Dublin ireland. Kept getting stuck on its back. Helped him on his way