Female Stag Beetles: How To Identify Them?

In the insect world, it is often hard to tell males and females apart. Take the stag beetle for example: how do you identify the female stag beetles? Find out by reading the article below.

Female stag beetles are smaller than their male counterparts. The stag beetle females mate with the male to lay as many as 20 eggs at a time.

They usually lay their eggs in rotten or decaying wood and tree stumps because the wood and tree sap becomes food for their larvae, which is due to come out in a few weeks.

There are many exciting things to learn about female stag beetles, so keep reading to find out more.

How To Identify Female vs. Male?

There are over a thousand species of stag beetles in the world. The Lucanidae family is home to giant species that can grow more than 4 inches.

However, the average length of an adult beetle is only around 2 inches.

The stag beetle population comprises both males and females, but it is sometimes difficult to tell which is which.

The simplest way to identify a female from a male is via the mandibles. The female beetles have small but powerful mandibles, whereas the males have large but ineffective ones.

In the larval stage, the females can be distinguished from their male counterparts due to their cream-colored ovaries, which are visible on their backs.

Lastly, in almost all species in the family, females are smaller than males on average.

How Big is a Female Stag Beetle?

Female stag beetles have smaller mandibles than males. Thus, females have a smaller body size than males.

A typical female stag beetle is between 24-48 mm compared to a male, who is usually 35-37 mm.

How Do They Mate?

There is a reason why male adult stag beetles have large mandibles. They use them to wrestle with each other because it helps decide which one gets to mate with a nearby female.

The mating ritual between stag beetles begins with the male widening its antlers and showing them off to the female.

If there are multiple males, as mentioned already, there is a fight-off. The one who can hold up the opponent on its back with his beetles becomes the winner.

Usually, these fights can last for several minutes, especially if the two males are evenly matched..

The winner is considered ‘aggressive’ enough to mate with the female. Once the mating is complete, the female finds moist dead wood or tree stumps to lay eggs.

Where Do They Live?

Stag beetles are found worldwide, including in the US, UK, parts of Europe, Asia, Australia, and Africa.

In the US, you can find about 30 stag beetle species, many of which can be found in the Kentucky region. The cottonwood stag beetle species are found in Arizona.

Stag beetles are usually found in areas with less rainfall and high temperatures. It is easier for them to find primary food sources like tree stumps, sap, wood chips, and log piles.

There are three main species of stag beetles found in the UK. The first is Lucanus Cervus, the most popular species of stag beetle in the UK.

The second is Dorcus paralellapipidus, the relative of Lucanus Cervus and lesser stag beetle, and finally, Sinodendron cylindricum, also known as the rhinoceros beetle.

How Many Eggs Do They Lay?

A typical stag beetle female lays around 30 eggs in one go. The egg laying happens in late summer, and it takes about 2-3 weeks for the eggs to hatch.

Where Do They Lay Eggs?

The female adult stag beetles lay eggs in rotting wood or pile beneath the soil. She may also lay eggs in dead wood chips because the stag beetle larvae feed on decaying and rotten wood.

What Do The Larvae Look Like?

The stag beetle larvae are white-colored insects with orange heads. They have three pairs of legs, the same as a fully-grown adult beetle.

They also have small brown antlers, which are nearly invisible to the naked eye. The larvae take about six years to grow to full size.

During this time, they go through several instar stages, growing by feeding on rotten wood.

What Do They Eat?

Adult stag beetles only live for a few weeks, using up the stored fat from their larval stage.

However, they occasionally get moisture and energy from tree sap and decaying fruits.

The larvae feed on rotting wood until they transform into adult beetles.

Frequently Asked Questions

Wrap Up

The more you learn about them, the more the female stag beetles seem fascinating.

After all, they are courted by males who fight over them while they wouldn’t move an inch for the male’s benefit!

They have a simple life cycle, and when the time comes, they are good mothers.

They make sure to lay eggs only near a good source of food so that their larvae can survive and thrive for years to come.

Thank you for reading all about them!

Reader Emails

We have often had the pleasure of receiving photographs and letters from our fans inquiring us about stag beetles, and specifically wanting to know whether they have encountered a male or a female. 

Do go through these letters below to get a good look at the pictures and how you can visually tell the males and females apart.

Letter 1 – Female Stag Beetle

 

what’s hidding behind the door? Location: Decorah Iowa July 8, 2011 4:48 pm ’Ello. Found this beetle outside the back door. I live in an apt that’s half underground so there are cement steps and a covered drain (he did not get in that way) out the back door. I have lived in northeast iowa for tweny years and haven’t seen this beetle before. this is the second unknown large beetle I’ve found in 3 days! Was able to identify the first one (a beautiful ”caterpillar hunter”), but can only find ones that kind of look like this one. The closest identificatin I could find was the Eger’s earth boring beetle, but I’m not sure this is correct due to the antennas (please excuse my lack of bug speech). He is black and just over an inch long. I have included photos taken with my phone. I appreciate any help you can give and thank you for your time. 🙂 Signature: Surprised in Iowa

Dear Surprised in Iowa, Because of the large mandibles and clubbed antennae, we believe this is a female Stag Beetle.  It looks very similar to Lucanus placidus, which we found on Bugguide and there are records of sightings from Iowa.  The front legs are quite distinctive, and they match this image from BugGuide.  We have contacted Eric Eaton to get his opinion.

Letter 2 – Female Stag Beetle, but what species???

 

Reddish brown stag beetle? Location: Northern IL, US July 10, 2011 9:48 pm I was wondering if you could verify that this bug is a female reddish brown stag beetle. We just recently had a terrible storm that destroyed several trees in my friends backyard. Shortly after, I found her(I really don’t think its a him considering those small pincers) I read somewhere that reddish brown stag beetles tend to be around rotting wood and we’ve got a lot of that thanks to the fallen trees.  Despite those scary looking pincers she really is quite docile and i had no problem with her crawling on my arms.  My friend wanted to light a fire cracker on top of her but I smacked him 😀 Teenage boys sure are stupid sometimes :/ anyways, thank you! p.s. this picture was taken in early July Signature: Brie

Hi Brie, We agree that this is a female Stag Beetle, but we cannot say for certain that she is a Reddish Brown Stag Beetle, Lucanus capreolus, pictured here on BugGuide. She may also be a Giant Stag Beetle, Lucanus elphus, which is pictured on BugGuide as well. Thank you for rescuing her from being blown to smithereens.

Letter 3 – Female Stag Beetle

 

Is THIS a stag beetle? Location: Plymouth, Michigan July 11, 2011 8:40 am This large beetle was seen just after dark on July 10, 2011. It was about 1 1/2” long and was purposefully marching across my suburban patio. My dogs were very interested but I think I got them away before they did any harm. Is this perhaps a female stag beetle? I remember seeing them a few times as a child (40 years ago) and I always thought they were very cool. Signature: Holly

Hi Holly, This is indeed a female Stag Beetle, however, we cannot say for certain if it is a Reddish Brown Stag Beetle or a Giant Stag Beetle.  We would defer to the experts in the species identification, however, the genus is Lucanus.

Letter 4 – Female Reddish Brown Stag Beetle

 

Curious Beetle Location: Cook County, Illinois July 30, 2011 12:02 pm The other day, I came across this beetle at work (donut shop, but it was in the lobby, between the entrance and the lavatory). Someone had already tried to step on it, but I scooped it up in a cup anyways, and set it in the bushes on the other side of the parking lot from the store. I took some pictures, and was just curious what this cute little critter might be. From browsing your site, and the one you link to, I’m guessing it’s a bark gnawer of some kind. But I would like to know for certain. Signature: Doctor McCrimmon

Dear Doctor McCrimmon, This is a female Reddish Brown Stag Beetle, Lucanus capreolus.  The larva feed on rotting wood.  Hopefully, your good deed spared her from other stompers.

Letter 5 – Lesser Stag Beetle from UK

 

Subject: Identification Location: UK August 9, 2012 1:25 pm Photo taken on 02/08/2012 in Worcestershire England. Signature: B Woodward

Dear B Woodward, This is the female of the largest and arguably most distinctive beetle found in the UK, a Stag Beetle, Lucanus cervus.  Stag Beetles have become increasing rarer in the UK in recent years and in many areas they are protected.  Here is a matching photo on the Space for Nature Garden Biodiversity Forum. Correction:  Lesser Stag Beetle Thanks to a comment by mardikavana, we are correcting this posting.  This is actually a male Lesser Stag Beetle.

Letter 6 – Female Placid Stag Beetle

 

Subject: Bug project Location: Wisconsin August 25, 2015 1:29 pm Hi there! My name is Jada and I am a highschool student in Wisconsin, for a summer project we had to collect and identify 25 insects and I am having trouble finding the name and classification for these three bugs, it would be great if you could help me out! If not that’s totally fine! Signature: Thanks! Jada

Dear Jada, We do have a policy that you should know about, but your communication is very polite and by our accounts, you should have already identified 22 insects for your project as you are only requesting assistance with three.  We will provide you with an identity for one and we will give you categories for the other two. Were we your teacher, the first thing we would ask is “How could an image dated January 8, 2015 have been visually collected this summer?”  This is a female Stag Beetle in the genus Lucanus, and after browsing BugGuide, we determined it to be a female Lucanus placidus based on the BugGuide description:  “Similar to L. capreolus, but much darker, elytra more punctate. Legs dark reddish brown, no light brown patches as in capreolus.”  Male Stag Beetles have much larger mandibles.  See this BugGuide image for comparison.  We are going to unofficially call this a Placid Stag Beetle based on the BugGuide definition:  “placidus – Latin for ‘smooth, pleasing.'”  Your other images are of a beetle and a true bug.  You can peruse our own archives or check BugGuide for the remaining two images.