Wednesday 26 January 2011

Dobsonfly

Image: Wikimedia
Male Eastern Dobsonfly
Oh. My. Gosh.

What on earth is this thing? It's huge! It has gigantic wings! It has massive... ANTLERS coming off its face! Has someone had a nightmare that's come to life or what?

What we have here is the Dobsonfly. An insect that can reach 12.5 cm (5 inches) in length, with a wingspan that can reach twice that. The most famous one is the Eastern Dobsonfly, specifically the male of the species, for it is he that has those huge, scary tusks.

Image: Wikipedia
Female Eastern Dobsonfly
I will add to the fear by saying that Dobsonflies have powerful jaws. OUCH! Except that males have such long jaws that they can't get the leverage necessary to inflict a strong bite. Some of the larger females on the other hand, can use their much more modest and manageable mandibles to cause pain and even draw blood. Sometimes the host who boasts the most would be better off keeping quiet. And sometimes it's the quiet ones you would do well to keep an eye on. (NINJA!)

Both males and females will raise their head and spread their jaws to deter predators. It probably works too. But it seems that males actually use those fearful tusks for the purposes of mating, like peacock feathers or deer antlers. It's weird how females are so often attracted to things that are completely useless. It is said that the male dobsonfly use their jaws not only for display, but also to fight with other males and also to hold the female during mating. So maybe they have some important function somehow. We'll have to ask the females.


Find more at memutic's channel. Wonderful stuff!

In truth, it may not be such a problem if they really were useless. Adult dobsonflies only live for about a week, it looks like they don't even need to eat. Instead, they spend most of their lives, several years, as freshwater larvae called hellgrammites. These have all the gills they need and strong (and short) pincers for eating the larvae of other insects. They are not great swimmers, spending most of their time under rocks. They also have small hooks at the tip of their tail for gripping, so that they don't get swept away in rivers and streams.
Image: Wikipedia
When the time is right, they crawl off to land, dig a hole in the ground to pupate in and an adult dobsonfly will emerge some weeks later.

Imagine going for a stroll in the woods at night and seeing one of these monsters clambering out of the ground fangs first! Maybe you shouldn't be strolling in the woods at night?

69 comments:

Brigitte said...

Very helpful. A bird just dropped a 3 inch male Dobsonfly in my yard and I had no idea what it was. Thanks for helping with the id.

Joseph JG said...

No problem, glad I could help!

Anonymous said...

I just saw one of these on my front porch while I was smoking a cigarette. Freaked me out a bit so I put a boot on top of it and looked it up on Google. It was pretty easy to identify by simply typing "Huge bug 4 wings large pincers". Found out what it was right away. It's still under the boot. I'm going to watch my mom move said boot tomorrow morning and watch her reaction. Might even film it.

Unknown said...

Captured one tonight in my children's bug box. It was on my front porch. Freaky.

In west va

Unknown said...

My 7 year old son just found a female one on our sidewalk. Ewww I can't get rid of these goose bumps.

Joseph JG said...

@92a69a7c-e7a2-11e2-ab26-000bcdca4d7a: Erk! That'll be a nasty surprise!

@Angela Mullins: Yeah, it's quite a picture. Not a pretty picture, but a picture.

@Paula Peterson: haha!

Unknown said...

I live in Minnesota, have my whole life and have never seen one of these until today. It's almost the length of a dollar bill. Talk about a nightmare! Scared the crap out of my kids too. They thought it was a crab bug. Haha I want to know though, do they carry disease?? And how the hell did it get HERE?!!?

Joseph JG said...

I don't think they carry disease, but they do live in Minnesota!

Ones like this:
http://www.entomology.umn.edu/museum/links/coursefiles/JPEG%20images/Megaloptera%20web%20jpeg/Corydalus.jpg

They're just a little secretive and aren't much attracted to anything humans have. Unlike wasps swarming your picnic!

Nicole said...

Never saw such a thing until tonight. My cousin and I have lived in rural PA our entire lives and lost our minds when this landed on our patio table at a bar. Everyone in the place came out to look at it. Truly looks like something plucked out of a nightmare.

Joseph JG said...

Ha! They definitely look quite nightmarish!

PLeach said...

The larva make excellent fishing bait. My husband used to catch them in the Raritan River in NJ. He'd break off the pincers with forceps before putting them on the hook. The smallmouth bass went crazy for them!

Joseph JG said...

Yeah, I hear fish love them. I wonder what they'd think if they saw what those tasty maggots become!

Unknown said...

We just had tons of rain and flash flooding here in Colorado and we went out and found a female Dobsonfly struggling for life on the back of our truck. We have no idea how she ended up there but she took us by surprised, considering we've never seen one in person before! Thank you for the information though, very helpful and informative!

Joseph JG said...

So cool that you spotted one! I'm glad I could help out!

Unknown said...

I loved your video . i fory first time found a Dobsonfly. i found the male. It was very scary. i put it in a vase to show my grandkids. . i live next to a river so now i know why i found it i 52 never seen one before. ty for the video. i learned. a lot from it. i i am wounding if he just crawled out of the ground now is only going to live for one week. i just mowed my yard. was racking the lawn when i found my first dobsonfly. i glad i didn't find the female. lol ty for the video. so i can tell my grandkids about the life of a dobsonfly. ty Rhonda from upstate ny.

Joseph JG said...

Glad you enjoyed! And yeah, the male is terrifying!

Unknown said...

This thing just freaked me out

Joseph JG said...

So it should!

Unknown said...

We took our kids camping this past weekend and had our 1st, and hopefully last, encounter with a male one. It seriously scared the crap out of me!!! Lol

Joseph JG said...

Haha! Good thing his face is worse than his bite!

Unknown said...

Very common in highlands at Santander department in Colombia (just now I'm peering a graceful female at home). They breaks in this season, just after big rains. have not seen any male yet. Only visible along one month or so.

Joseph JG said...

That's cool. That must be an interesting/terrifying month!

Unknown said...

What happens if it bites? Will it hurt, or cause any reaction? Or simple Neosporin and a Band-Aid? I what to know more then it's life span. We found one swimming today and it was in the water and the kids was inches from it being on them. What would happen?

Unknown said...

What happens if it bites? Will it hurt, or cause any reaction? Or simple Neosporin and a Band-Aid? I what to know more then it's life span. We found one swimming today and it was in the water and the kids was inches from it being on them. What would happen?

Unknown said...

Found one by the river while out pokemoning last night freaked me out

Joseph JG said...

@Claudia Mcgrath: The ones with the huge tusks can't actually bite effectively, the mouthparts are just too long for them to apply enough pressure. Smaller ones can bite pretty well but they have no venom or anything, it's just a normal nick.

@Unknown: They're pretty freaky so I guess that stands to reason!

Unknown said...

Just saw one of these (adult female) for the first time today while camping near a cold water creek in the mountains. So creepy!! But even more creepy knowing I could have stepped on one of the worms while walking in the creek. Always wear shoes when camping lol

Joseph JG said...

"Always wear shoes when camping"

That should be etched into a block of granite somewhere!

Haystack said...

I've seen exactly two of these in my 30+ years of living in Alabama. Both were male and both were huge. They are quite hilarious to watch as they flail so effortfully through the air with those enormous wings.

Even better was seeing the second one give up on flying and plop right on top of a stack of books a good friend of mine was taking to his apartment. Said friend is an entomophobe, even for little cute insects like ladybird beetles. He's not a macho man, but he's not a girly boy, either.

So, this big honkin' male Dobsonfly came down THUMP onto his books (yes, I -heard- it, from about 2 metres away), and the next thing I knew, books and insect alike were flying off in all directions as my buddy ran off, screeching as though the vilest Demons of Hell were hot on his heels.

I want to see another, please! Maybe a female one, this time? I'll be sure not to let her nip!

Joseph JG said...

Hahaha! This has got to be the WORST insect for an entomophobe. Big, heavy, massive scary-looking tusks, and it can fly but not fast enough to disappear quickly. And it's just about unfamiliar enough to be even scarier!

Unknown said...

I found one. It was huge

Joseph JG said...

Yup, they often are!

Shell and John said...

Just found one on a tree with dozens of other moths and such attracted by a light.we have been finding various moth wings on the ground lately, lots of lunar moths and big brown moths, then went out this morning saw dozens of wings scattered on the ground and looked up and spotted a female Dobson fly. Freaked us out. Also found a full set of wings on the ground. Most amazing morning find for sure.

Jerry Davis said...

Several of them on my porch recently. Found a large male on my leg tonight, sitting on the side of my bed talking to my wife:) U.G.L.Y., especially at night. We live in south Texas, and it is very dry in the summer. I have no idea where these buggers are coming from, as there is no water nearby. Except my water well...

Joseph JG said...

@Shell and John: Your own miniature safari!

@Jerry Davis: Sounds like ominous foreshadowing for a monster movie!

Unknown said...

My mother in law just posted one on Facebook,a male (according to your post) is on her screen door,one of her friends sent this link. We live in PA. Are they common here?

Joseph JG said...

Glad the post was useful! And yes, it looks like their quite common in your neck of the woods. The larvae are often used as fish bait.

Unknown said...

Found a female today at a patient's house on the porch she isn't quite dead... incollect dead insects for shadow boxes and she is beautiful. I've never seen one in my life so this site helped. Very cool. I'm not sure if she is at end of her life cycle or what. She is weak but still alive in container with vents. I could imagine those punchers hurting like a son of a gun.

Joseph JG said...

That's really cool, glad I could help!

Unknown said...

Thank you SOOO very much!!!
I am a West Virginia country girl/tomboy. I love getting muddy with my little boy & enjoy getting greasy at work (I'm a mechanic).
I LOVE watching horror flicks at midnight with all the lights out (& terrorize my fiancé with that lol)!
!!!I DO NOT SCARE EASY!!!
BUT...
My 9 year old just walked in with one of these!!! Thank GOD it was DEAD!!!
I have never EVER freaked out like that over A BUG!!! LOL
I have lived in WV my entire life - 39 YEARS! I have NEVER seen one of these THINGS & I pray I never do again!
These THINGS are one of God's creations that make me want to say, "WHAT WERE YOU THINKING?!?!"

Joseph JG said...

Hahaha! Well, at least your home range still has some secrets to offer, even they are terrifying!

Unknown said...

Wish I could add pictures! I found THREE of these on my door tonight! A male, a female, and a small one that I think is female. I think they are marvelous! Fascinating creatures.

Joseph JG said...

It's like a little family! That's so cool!

GhostEchoZero said...

So I just saw a male today! I am in Nacogdouches TX and it flew and landed by the light in a store. Me and another guy took pictures but didn't get to close because it looks so freaky lol. One of the workers picked it up and put it outside to fly away (eww)! I have never seen anything like that before. I am glad I got to see one in person after I read this.

Thanks for the info!

Joseph JG said...

You're welcome!

Joseph JG said...

Haha! Well, I guess the data is in and the experiment was a success. Sort of.

Unknown said...

So this morning i woke up to one crawling on my back and i woke up and went to grab or scratch whatever was on my back and it was a male it scared the crap out of me.

Jerry Davis said...

Brandon - finding one on your back had to have been a very bad moment :)

Unknown said...

Just found one at work right before it started raining. It was a male and it definetly scared me. I put it in a container so i look them up and watched him move and use his mouth. Whoch i think he was cleaning his mouth. It was very interestin insect to research.

Unknown said...

Yea it sucked

Joyce said...

We have found 3 on our front porch today alone why so many? There is no stream Creek or water source within 2 miles of our house

Unknown said...

Just found my cat playing with one of these on our back deck, apparently a male. Oh. My. Gosh. Is right! I thought it might be someone's pet from South America! Recently moved to Indiana from Houston where I thought flying cockroaches were the worst thing I had ever seen. I may never sleep well again!

Kris said...

North GA checking in - saw my first female settled quite comfortably a top the bug zapper. She's too large to crawl thru, otherwise I would've helped her out of danger. She's a beauty, I snapped some photos and left her to lounge. We had a unicorn beetle lounging on the bug zapper earlier, are they catching moths, or are they drawn to the light show? :)

Unknown said...

These are Soo weird... Just found one, barely alive, on her back at a gas station in Wilmington, IL. The long neck, well patterned wings, those eyes and mandibles... Wow! I didn't know what I was looking at. Typed "winged insect large mandibles" into Google and this was the first image. Thanks so much!

Unknown said...

I just found a male in somerset ky they are huge

Unknown said...

Just saw one of these at walmart in southern utah at first it looked like a huge moth being carried up the wall my another bug upon closer inspection this is what i saw freaked me right out lol

Unknown said...

Took a picture of one on the outside wall, live in Pa

Opasero said...

Just saw a huge female attracted to the light coming through my apartment building door. I shooed her off to the side because I figured someone would stomp her. Most people here just kill all bugs, and I figured if I was freaked out, they would certainly not put up with this huge creature. Then I googled to find out what the heck it was. She was just a little too creepy for me to touch, and I'm glad now because she might have bitten me! For sure interesting but kind of scary.

dm blog 1 said...

We have one on our garage - very freaky since we just had our cat diagnosed with a botfly larvae. Yeck! Des Moines, IA

Unknown said...

Just found one trying to fly into my house in franklin New Hampshire and it was terrifying lol but he didnt get in tho I did get several very good close up pics of him thru the window he wanted into.

Unknown said...

I woke up this morning,and was taking the garbage out for garbage pick up, and spotted this massive 5" creature on the side of our electric entrance box on the side of the house. After doing research,I found out that it was a Male Dobson fly.I live about 3 miles from the nearest river,and 2 miles from a stream, however it was located about 15 yards from our swimming pool.I won't show my wife the picture till the pool is closed for the season, LoL. We live in the small town of Kittanning which is located about 30 miles north of Pittsburgh Pa.

Unknown said...

Saw my first one today in Iowa. Must say it scared the crap out of me cuz was on my hand

lovinnature said...

My son saw one on his bedroom window screen in Hurricane, Utah today. Said it was a long as his phone, I thought he was exaggerating, but apparantly not! He was pretty creeped out, good thing it was on the outside of his screen! Haha!

Unknown said...

Live in New Hampshire had one on our front porch door took a pic.

Unknown said...

Danville science center (VA) was where we spotted a female Dobson fly!

emptyspaceman said...

I rescued a drowning one from a creek in Moab, UT! I thought it was a moth, never seen anything like this before. So cool!! Support your local predators so they can eat up those black flies! 😄

Unknown said...

Wish I could post the picture of the one I got. It was a female and easily 5 inches. Massive bug!

Grow up folks said...

Hello everyone. FIRST OF ALL JUST BECAUSE IT LOOKS NASTY DOES NOT MEAN TO KILL IT. THEY ARE GOOD INSECTS THAT HELP THE ENVIRONMENT BECAUSE OF CHILDLESS MINDS LIKE THAT MANY INSECTS ARE GETTING ENDANGERED.
GROW UP, LEAVE THEM ALONE AND LET THEM LIVE.
THE POOR MALE ONLY LIVES 3 DAYS AND THE FEMALE 7 DAYS.

ReadingTheBibleWithMe said...

Just moved to Do Salavador a month ago and saw a female trying to get into my friends room. Scared her so bad that she called it a demon! Giant bug!