Did you find a large, scary-looking creature flying in or around your house? It might be a dobsonfly. In this article, we talk about how to get rid of dobsonfly and whether you need to do it at all.
If you live near a body of water, there’s a chance that you might find dobsonflies in your home. While these large insects look quite intimidating, they aren’t a threat to humans.
Still, nobody likes one of the largest insects flying around in the house. The dobsonfly is mostly a nuisance pest, although the females are capable of delivering bites powerful enough to draw blood.
If you’re here reading this article, you’re probably trying to find out how to get rid of these massive bugs.
How Did I Get Dobsonflies?
Dobsonflies ending up in your home were likely drawn to your lights. They are nocturnal creatures, and like many others in the insect world, they find lights irresistible.
Dobsonflies are mostly aquatic insects, spending the entire larval stage of their lives (three to four years) in the water.
Their larvae prefer shallow and fast-flowing water bodies, such as small rivers and streams. Full-grown dobsonflies live on land but usually stick close to bodies of water.
If your house has outdoor lights that you keep on during the night, and you live near a stream of running water like a river, you might find them in and around your house.
They usually don’t like to come inside, but if your window is open just a crack and your lights are on, they might venture inside.
How To Identify Them?
Dobsonflies are easily identifiable thanks to their unusual appearance. The males have one or more inch-long, sickle-shaped mandibles, which give them a menacing look.
The jaws on female dobsonflies are shorter and resemble pincers. The females can bite using these jaws, but the male’s mandibles are not useful in biting.
From the end of the mandibles to the tip of the wings, these bugs can grow up to 5 inches long. Their size and color may vary from one species to another.
Another noticeable feature of the dobsonfly’s appearance is its wingspan, which can be twice as long as the body.
The wings are similar to those of a grasshopper’s – two pairs of narrow translucent wings stretching out on either side when spread.
As for the color, they are usually dull brown or tan. However, some species, such as the Eastern Dobsonfly, can also be bright yellow.
Can They Bite?
Although the mandibles of the adult male dobsonfly are large and scary looking, they are unsuitable for biting.
They don’t get enough leverage because they are fleshy, and therefore even if they try to bite, it doesn’t do any damage. A bite from a make dobsonfly feels merely like a strong poke or pinch.
Female dobsonflies can inflict painful bites with their short, sharp, and pincer-like mandibles, powerful enough to pierce the skin.
However, they aren’t aggressive at all and would bite you only if you handled them roughly. Neither male nor female dobsonflies are venomous or poisonous.
Do They Spread Disease?
Don’t worry; despite their scary appearance, dobsonflies do not spread any diseases.
Apart from the sharp, stinging pain, a dobsonfly’s bite doesn’t cause any issues either. However, they might release foul odors in your home if they feel threatened.
How To Get Rid of Them?
Before you take up pest control solutions to eliminate the dobsonflies in your home, consider whether it’s really necessary.
However, if you’re keen on eliminating the dobsonflies immediately or there are simply too many of them in your home, you may use insecticides.
Leave Them Be
In most cases, they don’t require pest control as they’re just nuisance pests and don’t cause either disease or any other damage.
As adult dobsonflies live only a few days, it’s just a temporary and short-lived inconvenience. Moreover, dobsonflies don’t reproduce indoors – they lay their eggs in or around water bodies.
Hence, the best way to deal with dobsonflies is just to leave them be. Pesticidal control isn’t usually recommended.
Pesticides
However, if you’re keen on eliminating the dobsonflies immediately or there are simply too many of them in your home, you may use the Supreme IT insecticide.
Create a diluted solution by mixing an ounce of Supreme IT per gallon of water.
Now use a pump sprayer to spray this solution and treat the area around your home’s foundation.
Remember to cover three feet out from the foundation and three feet up along it. You’ll need a gallon of the solution per Sq.Ft. of area.
The treated area will need two to four hours to dry, until which you shouldn’t allow people or pets to enter the area.
How To Prevent Them From Coming to Your Home?
Since it’s likely your outdoor lighting that keeps drawing the dobsonflies, consider keeping the lights turned off. You may also replace them with yellow bug-safe lights instead.
If possible, keep your pool empty during the hatching season so that the bugs don’t lay eggs in it. Most importantly, keep the curtains closed over all your windows at night so that dobsonflies don’t make their way inside.
Frequently Asked Questions
What is a dobsonfly good for?
Like all other organisms, the dobsonfly also has a role in the ecosystem. Their larvae help keep the population of other aquatic invertebrates in control by preying on them.
They are voracious predators of various insects, small fish, and other larvae which float by near their hiding places.
Apart from that, there are two uses specific to humans. They make excellent bait for fishing.
They are also useful to judge the quality of water, as they only live in clean water and are sensitive to contaminants.
Are Dobson flies rare?
The dobsonfly is an uncommon insect species, especially in the US. They’re more common in the Western Hemisphere, particularly in China and Vietnam.
However, you might still come across them near water bodies. The adults are very rare because they only live for 3-7 days, mating and reproducing to continue their clan, and then die off.
What is the life cycle of a dobsonfly?
Dobsonflies lay eggs on the leaves of plants. Each lay contains thousands of eggs at a time.
When the eggs hatch, the larvae emerge and immediately head towards the water. A dobsonfly spends three to four years in its larval form, known as hellgrammites.
It goes through 10 to 12 instars before it pupates into an adult dobsonfly. The adults live only a week or less, but it’s enough time for them to mate and lay eggs.
Can you hold a dobsonfly?
Yes, you may hold dobsonflies as they aren’t venomous or aggressive.
However, while holding a male dobsonfly is completely safe, you’ll have to be careful with the females. As mentioned earlier, their bites are painful, and they might bite you if handled roughly.
If you are planning to hold live larvae to hook for bait, make sure you hold it from behind its head because it can also inflict painful bites.
Do dobsonflies eat plants?
Don’t worry; dobsonflies don’t eat plants. Although hellgrammites are voracious predators, they only prey in the water. The adult dobsonflies don’t feed at all.
This is why the dobsonfly is merely a nuisance pest, and you shouldn’t worry about your plants if you find them flying around.
Wrapping up
Hopefully, this article has dispelled any fears you had regarding these large aquatic insects. You may rest assured that dobsonflies won’t harm your pets or damage your garden.
As mentioned, pest control measures are rarely necessary for these bugs. Thank you for reading, and I hope you can keep the dobsonflies out of your home in the future.
Reader Emails
Even though they are mostly harmless, their appearance often leads to their downfall.
Over the years, many of our readers have checked in with us about how to get rid of them, and here are some of the methods they have used in their quest.
Letter 1 – Dobsonfly Pupa
Hi!
First, wonderful site. Keep up the good work, and all that. OK, so, the bug: My nephew found it under some rotten wood near Grantsburg, Wisconsin, the other day. My sister saved the little guy from becoming fishing bait, and brought it to me ("Happy Birthday!"). My nephew said that there was what appeared a shed "skin" next to it when he found it, and it was a pale off-white when caught (it’s since turned brownish, as you can see.) It looks dead in the photos, but it is alive, and will squirm around if bothered. It’s legs don’t seem to be usable, however, and remain tucked under it’s body, as do it’s wings. So, do you know what it is? And do you have any ideas of how I can help it survive? Would it be best just to put it under a rotting log, or…? Anyways, thanks a lot.
Will Anderson, MN, USA
Hi Will,
You have a Dobsonfly Pupa. If you think it is scary looking now, just check out the adult males with pincer mandibles by using our brand new site search engine.
Hi… Hah! Oh, no. Thanks. When I showed some friends your site, they pointed out the dobsonflies and said “Jesus, I hope it’s not one of those!” Muahahaha. You wouldn’t happen to have any tips on care, would you? I’ve got it in a little cage now, with moist dirt and some of the wood it was found in. Should I bury it, or do you think out in the open is ok? I had it under a bit of wood, but it was across the cage in the morning. Oh, and it doesn’t need to eat, does it? Thanks again,
Will
Letter 2 – Not a Dobsonfly, but a Fishfly
I hope all is well with you. Last night I saw this big guy hovering around the flood light on the back of my house. I tried to get better pictures, but he moved around pretty fast.
Best Regards,
Ed Cogan
Hi Ed,
Thank you for the photo of a Fishfly, Chauliodes species. These are relatives of Dobsonflies, both belonging to the family Corydalidae. They can be recognized because of their comblike antennae. Larvae are aquatic predators, and it is likely that adults do not feed.
Letter 3 – Dobsonfly visits Gerald Ford Museum!!!!
Hello,
We just found this bug on our loading dock. Its total length must be at least 3-4 inches. I think some of our interns were sufficiently freaked out upon first glance. Could you tell me what kind of insect this is (see attached image)? I do not think I have ever come across a bug like this. Any help would be greatly appreciated.
Sincerely,
Jamie
James W. Draper
Registrar
Gerald R. Ford Presidential Museum
Grand Rapids, MI
Hi Jamie,
This is a male Dobsonfly. He is harmless. We had two photos on our homepage at the time you wrote in, including the Bug of the Month for June. We can’t imagine how you missed identifying the Dobsonfly yourself.
Letter 4 – Dobsonfly identified by WTB?
Hi,
Just found your super website and lo and behold – there it was – the gigantic insect I’ve been trying to give a name to! It was a Dobson Fly. Gave us a real shock when my granddaughter brought a dead one over in a large pickle jar that her neighbor found on her back porch. It measured 6 inches from wing ends to tip of pincers! We photographed it with our digital camera and have been trying to identify it ever since. Seems it pinched a lady in the neighborhood. It’s funny that I lived in this area for 60 years and never saw one before. Enclosed is our pic. Keep up the good work!
Barbara Erney
Harrisburg, PA
Hi Barbara,
Happy we could be helpful.
Letter 5 – Portrait of a Dobsonfly
Michael
Hi Michael,
I guess we chose our site’s name wisely. We have always maintained that everyone wants to know “What’s That Bug?” Glad we could be helpful. Your photo is pretty impressive.
Letter 6 – Not a Dobsonfly, but a Fishfly
I hope all is well with you. Last night I saw this big guy hovering around the flood light on the back of my house. I tried to get better pictures, but he moved around pretty fast.
Best Regards,
Ed Cogan
Hi Ed,
Thank you for the photo of a Fishfly, Chauliodes species. These are relatives of Dobsonflies, both belonging to the family Corydalidae. They can be recognized because of their comblike antennae. Larvae are aquatic predators, and it is likely that adults do not feed.
Letter 7 – Dobsonfly from Peru
We saw some dozens of flying insects beating against the window of our hotel in Agua Caliente, at the foot of Machu Picchu, Peru. The one attached was no longer working and was about 5cm long. This resembles nothing we know in the UK and I wonder whether you can identify it. Thanks
Peter Seamer
Hi Peter,
This is a male Dobsonfly. Very soon now, in the late spring and early summer, we expect to begin getting Dobsonfly submissions from the eastern U.S. At that time of year, it is one of our most common submissions.
Letter 8 – First Dobsonfly of the Year!!!
This bug was found in a crate at work. It was dead and there was this only one. This is the only picture I got of it, i hope that it helps. thanks
maria
Hi Maria,
Your photo is not the best quality, but it is significant since it is the first photo we have received this year of a Dobsonfly. This is a male. You can tell by his large mandibles. Just yesterday we received a photo of a Hellgrammite, the immature Dobsonfly.
Letter 9 – Dobsonfly larva
Hi
i LOVE your site, I was looking up the Dobsonfly larva, & noticed you only have one picture,so I thought you might like another one of the larva this one was 4- 5 inches long and about an inch wide, coulden’t belive it was that big, I have more pictures of it’s head,very close up, if you want them oh yeah the reason I e-mailed you was do you have a news letter? if you do I’d Love to get it,I can see why you got the yahoo pick of the week AWSOME SITE!! very well put together, & it’s easy to find what your looking for thanks,
Tina Johnston-Wilson
Goderich Ontario Canada
keep up the great work
Thank you so much Tina,
Your photo is beautiful. We do not have a newsletter. Just keeping the site updated is a handful, though we have toyed with the idea of trying to publish a book. Also thank you for the navigating compliment. I just received another letter from someone complaining she couldn’t find anything on the site. We would love to get the head photos.
Letter 10 – Dobsonfly Gets Screwed
Letter 11 – Dobsonfly Pupa
Letter 12 – Dobsonfly from Venezuela
Letter 13 – Mystery in the Dirt is a Dobsonfly
Letter 14 – Pupa of a Dobsonfly
Letter 15 – Dobsonfly Pupa
Letter 16 – Dobsonfly from Peru
Letter 17 – Dobsonfly from New Zealand
Letter 18 – Pupa of a Dobsonfly
Letter 19 – Western Dobsonfly
Letter 20 – Yellow Dobsonfly from India
Letter 21 – Dobsonfly Pupa
That is just horrible. I’ve encountered a couple of these guys in RL and they are completely inoffensive. They can’t even bite effectively with those goony jaws! (However, watch out for the ladies of the species, as THOSE can deliver a painful nip with their short and well-muscled mandibles.)
My reaction to the first one I ever saw was immense curiosity. It was a really poor flier and it was pretty clear to me from the way the male’s jaws were shaped that it couldn’t possibly deliver anything more than a gentle squeeze. I’ve handled male Dobsonflies and find them adorable in their goony, goofy way of moving about. You wouldn’t get me to hold a female, though.
What are they doing in my house, car patio,and everywhere I look ?, I live in Oregon, and how can I get rid of them,they bite more than just my toes?
What are they doing in my house, car patio,and everywhere I look ????, I live in Oregon, and how can I get rid of them,they bite more than just my toes?