Stage beetles live almost their entire lives underground, but what does a stag beetle eat when it finally comes out as an adult? Let’s find out.
A stag beetle is a rare and beautiful insect known for its long and threatening mandibles. However, these large jaws are more bark than bite.
While the larva of the stag beetle feeds on dead wood, including tree barks and saps, the adult doesn’t require eating and uses up the energy stored from larva food.
To learn more about what these interesting creatures feed on, continue reading.
What Is a Stag Beetle?
Stag beetles come from the age of the Jurassic Period, about 150 to 160 million years ago.
There are about 1200 stag beetle species worldwide, but you’ll find most of them in Europe and North America.
Stag beetles are quite a rare find these days. Collectors pay thousands of dollars for them.
They are experiencing decades of decline (due to the loss of habitat and food sources). For insect lovers, the best place to look for them is the UK.
What Does It Look Like?
Stag beetles are giant insects with a hard outer shell and two pairs of wings. The average length of an adult male stag beetle is between one and two inches.
However, the giraffe stage beetle, commonly found in southern Asia, can grow up to five inches long and is one of the world’s largest beetle species.
The most prominent feature of stag beetle is their mandibles (1.4-2.1 inches), which resemble the antlers of a deer.
With these massive jaws, an average adult beetle can be up to 3 inches long, making it the largest beetle in the specie in Europe.
Stag beetles are usually black or brown, but some species, like the Australian rainbow stag beetle, may also be colorful.
The male adult beetle is larger than females, primarily due to bigger mandibles. The stag beetle larvae, however, are even larger than the male beetles, with an average length of three inches.
Where Does It Live?
There are more than a thousand species of stag beetles across the world. However, you will find the most popular kind of stage beetle species in the UK:
- Lucanus Cervus,
- Dorcus paralellapipidus (relatively smaller than Lucanus Cervus), and
- Sinodendron cylindrical (also known as rhinoceros beetle).
In the US, you can find the cottonwood stag beetle in the state of Arizona on the southwestern side. A variety of these beetles also live in Australia and southern Asia.
Stag beetles can be found in areas with less rainfall and high temperatures since they spend most of their lives underground.
Thus, a hot and humid climate is good for the survival of these species.
What Does It Eat?
A typical stag beetle diet includes fluid from tree sap, tree bark, tree stump, wood, or decomposed fruit.
They usually rely on sweet fluids, but there is a difference between what stag beetles eat as an adult and as larvae. Here are the differences.
As Larva
The larva uses its jaws to cut through dead wood to find the splinters and looks for the white rot to feed on.
Amongst the trees, larva usually likes the rotten wood of oak trees but would also eat up willow, ash, lime, sycamore, horse chestnut, etc.
Since they eat only dead wood, the shrubs and plants remain unharmed but don’t spare organisms like fungi.
As Adults
Stag beetles spend most of their lives underground as larvae. When they finally become adults, they only have a few weeks of their lives left.
They do not eat much during their adult life. They use up the energy of the food they eat during the larval stage, and their primary concern is to reproduce.
What Eats It?
Stag beetles have predators like crows, foxes, lizards, amphibians, small mammals, kestrels, and birds.
Depending on the insect’s habitat, the predators may also include bats, raccoons, hedgehogs, skunks, moles, rodents, snakes, frogs, fish, dragonflies, ants, spiders, even other beetles, etc.
Predators often look for them during their mating season since they are vulnerable at that time.
Unique Mating Habits
The massive mandibles of the male stag beetle are used to fight other male contenders during the mating season.
With their antler-like mouths, they fight the other male aggressively to remove him from the way so it can mate with female stag beetles.
The male uses its mandibles as a warning signal to the competitors by raising its body to stand on its hind legs.
It can aggressively pick up and throw the opponent to the ground using the same posture, much like a wrestler. The winner of these battles is the one who gets to mate with the females.
If the rivals are endowed with equal-sized mandibles, these battles can last quite a long while. But in the end, it’s almost always the one with the bigger claws who wins.
Size does matter, at least in the insect world!
Apart from eliminating its rivals, the male beetle also uses its mandibles to court the female. The male circles the female with the “antlers.” while mating.
Frequently Asked Questions
What can I feed a stag beetle?
An adult stag beetle usually relies on the energy stored from the food consumed during the larval stage. They don’t live for longer than a few weeks.
A larva feeds on dead wood, including tree sap, tree bark, etc., of trees like oak, horse chestnut, and willow.
How do you keep a pet stag beetle?
Keep the beetle in a plastic or glass box with humid soil and good ventilation. Keep the temperature hot and humid, and ensure the box is at least five times larger than the beetle.
Make sure to spray some water in the jar regularly and feed them beetle jelly once or twice a day.
What do stag beetles need to survive?
Stag beetles spend most of their lives underground and, thus, survive easily in a hot and humid environment. They prefer to live in areas with low rainfall and high temperatures.
Females prefer light or flaky soil where they can easily lay their eggs, so they can easily dig out of the soil after pupating.
How long do stag beetles live?
Stag beetles can live up to 7 years, which is considerably longer when compared to other insects. However, the stag beetle spends most of its life as a larva and stays underground.
They come out of their cocoon after six years as pupa and turn into adults after a few weeks.
Wrap Up
We hope this article helped you learn something about these beautiful creatures. With a rapid decline in their population, stag beetles are becoming harder to find every day.
These insects feed on a variety of dead wood, helping to decompose it. They don’t cause us any harm, and we are the ones causing much harm to them.
Thank you for reading!
24 Comments. Leave new
Is there any way that I can get this species?
I am looking for this species right now so I hope I can get some from you. I live in Alabama.
Please clarify your intentions once you receive your request.
Help me. I want to know about this insect. I found them inside of my house, first in basement and after in kitchen and everywhere. Im going crazy and I don’t sleep all the night. Please can you help me to know why inside of house. Thank you.
I found one of these upside down on our outdoor wooden stairs and another one in our basement – more active than the one upside down. I carried them both off to the tall grassy area across the street and hope they made it! I also hope I don’t find anymore of them – they are huge and the pincers look scary! This is in Massachusetts – July, 2014
Was laying in bed and one crawled up me girlfriend leg. I’m not a bug guy AT ALL…. where did it come from? How’d it get in my bed we just moved in a week ago n house was clean? What does it eat n where does it sleep?
I live in North east iowa close to Mississippi. Thank you n much appreciated if u could give me some advice? How big of packs do they run on?
whenever I encounter one of these is where they have no business being, then learn a couple dance moves in the bug zappers
next time put them back in a wooded area where they can benefit our natural environment.
I live in West Michigan. Starting every May, we get thousands of these beetles coming up out of our yard. I have pictures and videos I can send after work today.
Please use the Ask What’s That Bug? link on our site to submit images.
I have tons of them also in Michigan, hundred everywhere. How do I kill them
I have a ton of these in my basement in Minnesota. Why are they in the basement if they like rotting wood? Does that mean I have some sort of rotting wood in the basement that the larva are hatching out of? I don’t think (hope) we have any rotting wood in the basement, so how then did they get there?
I have caught quite a few and take them outside, but really am not fond of so many in the basement. What do the adults eat?
Do I have to worry about them in the house? Will they destroy wood?
Are you certain you are not encountering predatory, beneficial, Big Headed Ground Beetles?
A reply to the person who has a yard full of Stag beetle I also have a yard full I am in Midland Michigan I thought they were June bugs but they are coming up out of the ground leaving behind a nice little hole I didn’t know what they were in till I found this web site but we do burn wood it is stacked neatly away from my house but I could live with out them they are evil looking. I can’t set outside at night now I do find a lot of them are died. Good luck to you who have them.
I left a message earlier this evening from Midland Michigan I re-read what you said about having a bountiful food source and I would say yes our soil or yard is rich with grubs we also had a tree cut a few years ago they left the stump because it was to large to deal with so it is slowly decaying.We do have wood stacked but we burn through it never lasting a year or to but again thank you for the info every summer it is always something different here.
Commerce twp Mi
Found the first one of the year tonight
And so it begins. Had 53 last year
First one last year was june 2
yard full of them west Michigan grant TWP a few stumps in the yard moles are horrible this year as well caught six in a five day period already this year.
Commerce twp Mi
Found the first one of the year tonight
And so it begins. Had 53 last year
First one last year was june 2
I live in Ionia, MI.
We get these black beetles every year and yes they do pinch people, my granddaughter was piched by one. Like Jameson from Grant, we too have ALOT of ground moles burrowing all over our yard, bad.
Every year we start seeing these beetles in late May early June, usually are dead or gone by end of June. Always black ones, don’t believe or recall ever seeing any with a reddish tint though. We have rabbits, horses, goats, cats, dogs, we thought they were dung beetles til a friend of ours came over that works for pest control and said they’re called Stay beetles.
I live in Ionia, MI.
We get these black beetles every year and yes they do pinch people, my granddaughter was piched by one. Like Jameson from Grant, we too have ALOT of ground moles burrowing all over our yard, bad.
Every year we start seeing these beetles in late May early June, usually are dead or gone by end of June. Always black ones, don’t believe or recall ever seeing any with a reddish tint though. We have rabbits, horses, goats, cats, dogs, we thought they were dung beetles til a friend of ours came over that works for pest control and said they’re called Stay beetles.
We catch like 20 every night. They are very large and have big pinchers. One bit my leg and it swelled and turned purple. The whole leg! These are very scary and if bitten seek medical attention.
Is there someplace I can post a pic of the large black beetle I found inside my house? I’d like to identify it.
You may submit your image using the Ask WTB? link on our site.
i had a slew of them in my yard this june hundreds of them i got a photo of the doing it yes they were making babies. i would take the dogs out at night and use the pooper scooper to gather them and take them to the center of the drive and in the morning they were all gond. so birds or possums or ?? came and made a meal out of them. or they crawled away to the woods. my pup git her lip bit by one, she was not a fan after that.