What Do June Beetles Eat: A Quick Guide to Their Diet

June beetles, also known as “June bugs” or “green June beetles”, are a fascinating group of insects that are commonly found in gardens and backyards during the early summer months. In this article, we will briefly discuss what June beetles eat and explore their feeding habits.

As a garden enthusiast or a curious observer, you might have encountered these metallic green insects and wondered about their diet. June beetles primarily feed on an array of plant matter like leaves, fruits, and flowers. Specifically, they are drawn to ripe, thin-skinned fruits like figs, thus earning them the nickname “fig eaters”.

Besides snacking on fruits, June beetles are also known for their taste for your garden’s lush green foliage. Keep a lookout for these insects during the summer months, as understanding their dietary preferences can help you protect your precious plants and maintain a healthy garden ecosystem.

Understanding June Beetles

June beetles are part of the family Scarabaeidae and the subfamily Melolonthinae, which belong to the order Coleoptera. They are referred to as scarab beetles and can be found in various species across North America. The adult beetles are reddish-brown in color, and they have a distinctly robust, oval-shaped body.

You might wonder what these beetles eat. They have quite diverse eating habits depending on their life stages:

• Adult beetles: They mostly feed on leaves, flowers, and fruits of various plants. For example, they enjoy eating the foliage of deciduous trees and may also consume ripened fruits. Although they do not cause significant damage, it is still essential to monitor their feeding if you have a garden or fruit-bearing trees.
• Larvae/grubs: In their larval stage, known as “white grubs,” these beetles feed on organic matter and plant roots in the soil. They can be quite destructive when present in large numbers, causing damage to lawns and crops as they munch away on the roots.

When you compare June beetles to other beetles or insects, it’s essential to understand their specific features. Here are some of their key characteristics:

• Size: Adult June beetles measure approximately ½ to 5/8 inches long.
• Color: They are reddish-brown in color, and their distinct hue helps in easy identification.
• Life cycle: The beetles have a complete life cycle comprising egg, larval, pupal, and adult stages.
• Habitat: They can live in various habitats, including forests, fields, or your backyard garden.

Now that you have a better understanding of June beetles, you can appreciate their characteristics and feeding habits. Remember to monitor their activity to maintain your garden’s health and always be aware of their presence to take preventive measures if required.

Life Cycle of June Beetles

June beetle’s life cycle begins in the form of an egg. When spring arrives, females lay their eggs in the soil, which hatch into larvae after 7 to 10 days. As a larva, also known as a grub, they feed on the roots of plants. During this time, you may notice them in your garden or lawn.

The larval stage lasts for a couple of years. In this period, they grow through a series of molts, getting bigger each time. As temperatures drop in winter, the larvae burrow deeper into the soil to hibernate. When the temperature rises again in the spring, they resurface to continue feeding.

As summer approaches, the fully-grown larvae transform into pupae. This stage is brief, typically lasting just a few weeks. During this time, the pupa remains in a semi-immobile state, encased in a thin shell and gradually transforming into an adult June beetle.

Adult June beetles emerge from the soil usually in late June through July. They’re active insects, with the males using their large feathery antennae to detect and locate females for mating. Once they find a mate, the cycle starts all over again.

Diet and Feeding Habits

June beetles have different feeding habits depending on their life stage. The larvae, known as white grubs, primarily feed on plant roots, especially those of grasses. In contrast, adult June beetles enjoy feasting on a variety of plants, such as the leaves and flowers.

During their larval stage, white grubs can cause significant damage to turfgrass by consuming the roots, particularly at nighttime. However, green June beetle larvae are considered minor pests as they feed very little on roots and instead prefer to eat decaying organic matter.

Adult June beetles typically search for food during the night, attracted to the foliage of various plants. They tend to remain hidden during the day, avoiding direct sunlight.

Below is a comparison table of their feeding habits:

In summary, June beetle larvae, also known as white grubs, mainly consume plant roots while adults feed on leaves and flowers. They are more active feeders at night, trying to avoid the light.

Common Habitats

June beetles, especially the Green June beetle, can be found in various habitats. They are native to the eastern United States, but their range extends from Connecticut to Florida and Kansas according to the University of Arkansas. These beetles can be found in gardens, lawns, and crop fields where they typically feed on decaying organic matter and roots.

In these habitats, June beetles play a vital role as decomposers, breaking down organic matter in the soil. They also serve as a food source for other animals like birds and small mammals. The larvae, or grubs, live underground and feed on the roots of various plants, including turfgrass. This feeding behavior can sometimes lead to damage to lawns and crops, making them a concern for homeowners and farmers.

Let’s compare the habitats of June beetles within North America:

While they are more abundant in the eastern United States, June beetles have also been spotted in parts of Canada like Nova Scotia, although they are less common there. In California, some species of June beetles can be found in gardens and lawns, but they may not be as prevalent as in other regions.

To summarize:

• June beetles inhabit gardens, lawns, and crop fields.
• They feed on decaying organic matter and plant roots.
• Their range covers the eastern United States, some parts of Canada, and California.

By understanding the common habitats of June beetles, you can better anticipate their presence and help manage any potential damage they may cause to your plants and lawn.

June Beetles and Human Interaction

June beetles can be a nuisance for humans, as they are considered pests in some areas. Their larvae, known as grubs, can cause damage to lawns and gardens by feeding on the roots of plants.

To prevent June beetle infestations, you can take several steps:

• Keep your lawn healthy and well-aerated to discourage grubs from feeding
• Use natural predators like nematodes to help control grub populations
• Remove any rotting fruits or vegetables from your property, as they attract adult beetles

In cases where prevention measures aren’t enough, insecticides may be used as a last resort. However, it’s essential to use these chemicals responsibly and follow the product instructions carefully.

In summary, June beetles are pests that can cause harm to lawns and gardens. By taking preventive measures and using insecticides when necessary, you can protect your property from these insects.

Impact on Gardens and Agriculture

June beetles are known for their potential damage on gardens and agriculture. They have a particular preference for vegetables, corn, small grains, potatoes, fruits, and strawberries.

June beetle larvae, also known as white grubs, can cause the most damage by feeding on the roots of plants, including those in pastures, golf greens, and golf courses. The adults, while not as damaging, may still feed on the leaves and flowers, causing visible harm.

Here’s a brief breakdown of how June beetles can impact various plant types:

• Vegetables and Fruits: The larvae damage the root systems, leading to plant death. The adult beetles may chew on leaves, affecting the plant’s growth and vigor.
• Corn and Small Grains: Grub infestations in these crops can lead to reduced yields, especially when the larvae attack the roots during the plant’s early growth stages.
• Potatoes: The beetle grubs can burrow into potato tubers, leaving tunnels and resulting in unmarketable produce.
• Strawberries: Larvae feeding can weaken or kill plants, while adults can damage foliage. This reduces the overall fruit quality.
• Pastures, Golf Greens, and Golf Courses: Grub infestations can cause severe turf damage, leading to costly repairs and maintenance.

To sum it up, June beetles can pose a significant challenge to your gardening or agricultural efforts. By understanding these pest insects’ feeding habits and the types of plants they target, you can implement effective management strategies to minimize their impact.

Natural Predators

June beetles, also known as May or June beetles, are not exempt from natural predators. These beetles often fall victim to a variety of animals and insects in their ecosystem.

Moles and Skunks

You’ll often find moles and skunks digging through your lawn in search of these beetles. Both animals are especially fond of June beetle larvae, known as grubs. Thanks to their keen sense of smell, these critters can easily locate grubs in the soil.

Birds

Various bird species are also known to feast on June beetles. For example, crows and blue jays are known to consume adult beetles, while robins and other ground-feeding birds prefer to eat the grubs.

Raccoons

Raccoons are opportunistic feeders and won’t shy away from a meal of June beetles or their larvae. Raccoons might tear apart your lawn or garden to get to these tasty morsels.

Vertebrates

Some vertebrates, such as small mammals or reptiles, might prey on June beetles. While not their primary source of sustenance, these animals will take advantage of the beetles when the opportunity arises.

Wasps

In addition to the vertebrate predators, June beetles also face threats from parasitic insects such as wasps. Some wasp species lay their eggs on or inside the beetle larvae. Once the eggs hatch, the wasp larva consumes the beetle larva, eventually killing it.

To sum it up, June beetles face a range of natural predators, from moles and skunks to various bird species, raccoons, and parasitic wasps. Each of these predators contributes to maintaining a balance in the ecosystem, ensuring the June beetle population doesn’t spiral out of control.

Distinct Species of June Beetles

There are several species of June beetles that you may come across. Here, we’ll discuss a few of them:

May Beetles (Phyllophaga spp.) are a group of over 400 species. They are usually dark brown but can be black, tan, or dark chestnut in color.

Japanese Beetles (Popillia japonica) are an invasive species in North America. These beetles have metallic-green bodies with coppery-brown wings.

Green June Beetles (Cotinis nitida) are larger and more robust than May beetles. They have a velvet green color with light brown or orange-yellow margins.

Ten-Lined June Beetle (Polyphylla decemlineata) is known for its distinctive ten-striped pattern on its back. Males have large, feathery antennae, and they are between 22 to 28 mm in size.

Here’s a comparison table to help you better differentiate between these species:

Though these beetles differ in appearance, they share some common traits, such as emerging in late spring or early summer and being attracted to light. Recognizing these distinct species can help you better understand their unique behaviors and ecological roles.

Longevity and Health

Maintaining a healthy lifestyle includes paying attention to the food and drinks you consume. June beetles, like many insects, have specific dietary requirements. Understanding their nutritional needs helps maintain their longevity and health.

June beetles primarily consume plant materials, focusing on leaves, flowers, and fruits. Their diet consists of both water and nutrients derived from their food sources. Adequate hydration is vital for their survival.

Plant materials provide the necessary nutrients for June beetles’ growth and development. Sources of protein, fat, and other nutrients are found in the plants they consume. As a comparison, here’s a table illustrating some typical nutrients June beetles acquire from their diet:

Remember, a balanced diet for June beetles helps them lead healthy lives. By understanding their nutritional needs, you provide an environment where they can thrive. Focus on supplying foods rich in protein, fat, fiber, and other essential nutrients. And don’t forget to provide water to keep them hydrated.

References

Green June beetles, scientifically known as Cotinis nitida, are native to the eastern United States and have a metallic green body. They can be found in many landscapes and are known for their fondness of ripe, thin-skinned fruits.

For instance, they are sometimes called fig eaters due to their preference for figs. They also feed on other fruits, such as peaches and grapes. Apart from fruits, adult green June beetles are attracted to flowers and tree sap, where they feed on nectar and pollen.

In contrast, the larval stage of the green June beetle, also known as grubs, has a cream-colored appearance and feeds on organic matter and roots in the soil. As they feed underground, they can cause damage to turfgrass and garden plants.

Here’s a quick comparison table to summarize the feeding habits of green June beetles:

In conclusion, understanding the feeding habits of green June beetles is essential to manage them effectively, especially if you want to protect your garden or fruit trees. To learn more about these fascinating creatures and how to control them, you can refer to resources like NC State Extension Publications and Penn State Extension.

Conclusion

In summary, June beetles have a varied diet, consisting mainly of turfgrass and other plants. For example, the tenlined June beetle feeds on tree fruits, such as apples, and other plants like strawberries, roses, and corn.

As a friendly reminder, these beetles can cause damage to your plants, so it’s essential to monitor their presence in your garden. Below is a quick comparison table highlighting the key features of two common types of June beetles:

Here are some common characteristics of June beetles in general:

• Rounded and robust body shape
• Active during May and June
• Can cause damage to gardens and lawns

When dealing with June beetles, it might be helpful to weigh the pros and cons of different control methods. For instance, chemical control may quickly eliminate beetles, but it could also harm beneficial insects and the environment. On the other hand, biological control methods, such as introducing natural predators, may be more environmentally friendly but could take longer to show results.

So, to keep your plants healthy, it’s essential to learn and understand the specific type of June beetle in your garden and determine the best control measures for your situation. Good luck, and happy gardening!

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Ten-Lined June Beetle

Arizona Bug
This was a bug that my dogs were so interested in, when I went to see it was so interesting looking, I had to take these photos–what is it? The tentacles are amazing.
regards
michael minkus

Hi Michael,
We wrote to Eric Eaton to get an exact species name for your Scarab. Here is his reply: "This one is a male Tenlined June Beetle, in the genus Polyphylla. Adults nibble a little on conifer needles, the larvae feed on roots of various plants. Never really numerous enough to do any damage. Females have much smaller antennae, not those paddle-like things the males have. Both genders can make an endearing huffing noise by scraping the abdomen against the inside of the wing covers. Very cute."

Letter 2 – Ten-lined June Beetle

My “Peanut Butter Log” bug…
Hi there. You were so helpful to recently identify my pleocoma, for which I thank you! However, I’d be curious to know what type of bug this is. I call it a “Peanut Butter Log” bug as it reminds me of the little striped candies I used to like (and STILL like, if the truth be told). I’m in Northern California. These guys show up in summer months and I am quite fascinated with their markings. Thanks in advance for your awesome site!
–Michelle Mahood

Hi again Michelle,
Beautiful photo of a Ten-Lined June Beetle, either Polyphylla decemlineata or P. crinita. I saw my first live specimens several months back when they were attracted to lights at the campus I teach at in Pasadena. Adults feed on the needles of coniferous trees and make loud squeeking noises when handled.

Letter 3 – Ten-Lined June Beetle

Ten lined June beetle
Hi:
We found this guy on our front step in Delta, BC Canada. Inquiries identified it for us and a follow-up search directed us to your site. I see a few photos of ten-lined on your site but thought you might like to add the photos we took as well. Unfortunately I didn’t think to take any photos once he spread his antennae. Thank you for hosting such an informative site.
Regards,
Tom Rohrer

Hi Tom,
Thanks for your wonderful contribution.

Letter 4 – Ten-Lined June Beetle

Look who I found outside… Eeewwwwwww… It’s him!
Hi Bugman,
I’ve checked the web & I can’t figure out what this is can you help? It flies, is about 2″ long & hisses. Thanks
Shannon Lambertson

Hi Shannon,
Thanks for sending in the photo of the Ten-Lined June Beetle.

Letter 5 – Ten-Lined June Beetle

Subject:  Big weird beetle like bug
Geographic location of the bug:  Vancouver BC
Date: 06/11/2018
Time: 02:58 AM EDT
Your letter to the bugman:  It flew in a window at night. It seemed to fly awkwardly and made a loud sound when flying. It also seemed to be grooming its antenna.
How you want your letter signed:  Rob

Dear Rob,
This is a Ten-Lined June Beetle and they are frequently attracted to lights.  They will also stridulate when handled, meaning they make squeaking sounds by rubbing body parts together.  Just last week, a large male Ten-Lined June Beetle was on the screen door at the What’s That Bug? offices in Mount Washington, Los Angeles.

Letter 6 – Ten Lined June Beetle claims American Flag

Bug Photo
Mr. Bugman,
I’m curious about the identity of this bug. Primarily, is it a threat to gardens? Thanks,
Pamela Thompson

Hi Pamela,
The Ten Lined June Beetle, Polyphylla species, feeds on the needles of coniferous trees at night, and the immature beetle grubs feed on the roots of a wide variety of plants. This beetle is never plentiful enough to be considered a threat to the garden, nor are they a threat to national security.

Letter 7 – Ten Lined June Beetle in Mount Washington

Subject:  Ten Lined June Beetle in Mount Washington
Location:  Mount Washington, Los Angeles, California
June 13, 2015 7:30 AM
Since we are in a drought, we are trying to be creative about saving water and keeping the garden from dying.  Though we are contemplating a grey water reclamation system, that requires some expense, but we have implemented several efforts to conserve.  We save shower water in a five gallon bucket and we save water from washing dishes in a big pot.  We then manually dump that water in the yard.  This morning while emptying the pot from the sink, we spotted this gorgeous Ten Lined June Beetle, Polyphylla decemlineata, on the screen door.  We have been in Mount Washington for twenty years and this is a first for us, though we are no stranger to Ten Lined June Beetles in Pasadena.  According to Charles Hogue in Insects of the Los Angeles Basin:  “They are attracted to light at night and are seen frequently at night in the San Gabriel Mountains and, occasionally, in nearby foothill communities.”  We are going to contact local lepidopterist Julian Donahue to see if he knows of any previous Mount Washington sightings.

Boris, our office cat, was quite enthralled with the large Ten Lined June Beetle on the screen door.  Adult Ten Lined June Beetles feed on pine needles, and there are two large pines on the grounds.  We didn’t want to disturb the critter for a closer look, but the antennae indicates this might be a male.

i’ve never seen these locally.
the closest location i can recall is seeing them on the carrizo plain.
nice photo of boris the toe biter, too!
Clare Marter Kenyon

Letter 8 – Ten Lined June Beetle rescued from feline

Subject: 10-Lined Beauty
Location: West Seattle, WA
July 10, 2014 12:58 pm
Hi there,
Last night, the cat brought what I thought was a small mouse into the house. Rushing to the rescue, imagine my surprise that it was instead a very large, very beautiful insect.
I’ve lived in this neighborhood all of my life (nearly 50 years) and never seen anything like it. As I was photographing it, I was touched by how sweet-tempered it seemed. It hissed when I gently assisted it into a rescue jar and didn’t move quickly when released back out into the yard. Even when it hissed, it was cute.
What was I so lucky to have met last night?
Signature: West Seattle Nature Lover

Dear West Seattle Nature Lover,
We would have guessed that based on your subject line, you realized you had an encounter with a Ten Lined June Beetle, Polyphylla decemlineata.  The hissing is created by a phenomenon known as stridulation, or the rubbing together of body parts, and it can be quite loud.  The Ten Lined June Beetle will stridulate when it is disturbed or handled. Because of your rescue intervention, we are tagging this posting with the Bug Humanitarian Award.

Letter 9 – Ten Lined June Beetles in Glendale and Mount Washington

Subject: Ten-Lined June Beetle
Location: Glendale, California
July 15, 2016 6:41 am
My sister sent me this image while at a railroad museum in Glendale. She said a little boy was harassing it when she came across it, which is why its wings are like that, I assume. Your site helped me identify it as a male. I think its beautiful.
Signature: JB from Vegas

Dear JB,
You are correct that this is a male Ten Lined June Beetle, but we wonder if the railroad museum you mentioned is Traveltown in Griffith Park which is in Los Angeles near the Glendale Border.  We are also including an image of a Ten Lined June Beetle we shot last night on our screen door with this posting.  Last year was the first time we have found a Ten Lined June Beetle in Mount Washington in the 21 years we have lived here, and it is now our third sighting of this year with the other two being females.  These sightings at our office represent either a range expansion, or a reintroduction of a previously extirpated species.

Letter 10 – Ten Lined June Beetles in Glassell Park and Mount Washington

Subject:  What’s That Big?
Geographic location of the bug: Glassell Park
Date: 06/04/2018
Time: 09:43 PM EDT
Your letter to the bugman:  Hello,
What’s this bug? It has joined us in the early glassell park evening. Sunglasses for scale.
How you want your letter signed:  Best Locust love

Dear Locust love,
This is a Ten Lined June Beetle.  Our editorial staff just saw one yesterday and we have been seeing them yearly recently.  Our first Mount Washington sighting was 2015.

Update:  June 7, 2018
Just as he was getting ready to leave for a holiday in Ohio, Daniel was visited by this Ten Lined June Beetle at our Mount Washington office.

Letter 11 – Ten Lined June Beetles: Unseasonal Appearance!!!

A dozen ten lined June bugs in my basement (so far) in October!!
Location: South Eastern Idaho
October 24, 2011 9:03 pm
We recently purchased a 100+ year old home. The home had been vacant since the spring. When we installed a new furnace and brought the home up to temperature last week 10/15/11 I noted a few days later several large bugs lying around in the basement. All were dead or nearly dead when found. I looked around and noted that in the area of the basement where the concrete floor doesn’t cover that there are some bore holes, about the size of an adult’s finger into the clay floor in this area. I was surprised to find them all dead and even more surprised once I found a picture on your website that let me guess what kind of bug it is.
Am I seeing an infestation? Are they waking and dying because we warmed up the home and they think it is spring? Will I have this happen over and over or are these beetles going to exhaust thier numbers after this false spring?
Signature: Rick

Hi Rick,
Since the larvae and pupae of the Ten Lined June Beetle live underground for several years, and since the ground temperature is a significant factor in the emergence of insects that live underground, it is likely that heating the basement triggered an early emergence for the brood of Ten Lined June Beetles you found in October.  We suspect that the clay floor might have provided a suitable location for a female to have laid eggs since the grubs feed on the roots of trees and shrubs.  We strongly doubt that the eggs were laid outside and the grubs tunneled to your basement.  We think it is more logical that at some point a female was trapped in the house and laid eggs on the floor.  We doubt that this pattern will repeat in future years, though it is entirely possible there is an isolated population of Ten Lined June Beetles that have been cyclically reproducing in the home if the required roots are near the surface of the clay floor.

Reader Emails

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Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Ten Lined June Beetle

Subject:  Beetle-type insect?
Geographic location of the bug:  NE Tacoma WA
Date: 08/02/2022
Time: {current_time} EDT
Your letter to the bugman:  Hi.  Came across this one just under the soil next to my house foundation in NE Tacoma.  Could you identify it, and is it dangerous to my home?  Thank you.
How you want your letter signed:  Tom

Dear Tom,
The Ten Lined June Beetle is a distinctive beetle that can be found in many of the western states during the middle of the summer.