Thread-Waisted Wasps and Humans: A Guide to Stings and Safety

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Thread-waisted wasps are comically thin! However, like all wasps, these guys can also be venomous. So, do thread waisted wasp sting humans? Let’s find out.

If you live near a garden or a yard, you must have seen insects flying around your house and outdoors with a tiny thread-like abdomens. 

These curious-looking insects are called thread-waisted wasps

Did you know that between the years 2001 and 2017, more than 1,000 people died from insect stings in the United States? 

After reading that, you might be thinking, are the thread-waisted wasps poisonous or venomous too? Do they sting like other aggressive wasps? 

What if we tell you they are not dangerous at all? This article will answer your questions about whether thread-waisted wasps are dangerous to us. 

Do Thread Waisted Wasp Sting Humans

What Are They?

Thread-waisted wasps belong to the Sphecinae family of solitary wasps and are known for their extended thread-like abdomen area. 

These wasps are found all over the world, and many of their species are present in North America as well.

These species of wasps are known by various names, including sand wasp, digger wasp, mud dauber wasp, hunting wasp, caterpillar-hunter, and cicada killer.  

Thread-waisted wasps are typically more than an inch long in size. They prey on insects like spiders, caterpillars, crickets, and cockroaches

With their venomous sting, they stun the prey, which they later store in a cell of their mud nest where they lay eggs. Upon hatching, their larva consumes the stored prey. 

Since they hunt pests, gardeners like to have them build nests in their gardens and yards. 

These adult wasps nest in the ground or construct free-standing nests from mud on a flat surface or some pre-existing cavity. 

The female wasps are primarily vegetarian and sip nectar from flowers throughout their lives except when they hunt to provide protein for the young ones.

Are Thread Waisted Wasps Aggressive?

Most thread-waisted wasps are not considered social wasps; they are generally solitary nesters. 

Being a solitary species, they are not aggressive towards humans until we try to handle or harm them. 

Ensure you are careful around the nest of a thread-waisted wasp; accidentally stepping or touching them may lead them to sting you as an act of defense. 

Do Thread Waisted Wasp Sting Humans

Are Digger Wasps Aggressive?

Digger wasps are known for their enormous size and build. Due to this, many people consider them to be highly aggressive, which is entirely incorrect. 

Of the species found in the United States, the Great Golden Digger wasps are non-aggressive to people and pets. 

You will be surprised to know that the males have no stingers; the females, on the other hand, have a stinger, but their venom is limited, and they save it for hunting the prey for laying their eggs.

Are Mud Daubers Aggressive?

Mud daubers are unlikely to sting and attack humans. These insects are also solitary and don’t defend their nests. In fact, they are actually beneficial because they help control spiders. 

However, you should take care when these wasps abandon their nests. There is a possibility that other more aggressive pests may take them over, which is why it is good always to cover up the nests if you don’t see the wasps around for a few days.

Do Thread Waisted Wasp Sting Humans

Are Sand Wasps Aggressive?

Sand wasps are capable of delivering painful stings. Still, they are docile creatures and are rarely seen attacking humans or pets. 

However, they will attack if you try to manhandle them or their nests. Therefore be careful while approaching their nest. 

Are Thread Waisted Wasps Dangerous?

While insects like paper wasps and yellow jacket wasps are considered aggressive and dangerous, thread-waisted wasps like grass-carrying wasps, digger wasps, and more are not considered harmful. 

On the contrary, these insects are considered beneficial because they prey on many pests insects. Thus, making them excellent sources for pest control. 

Gardeners and plantation owners prefer to have them around their yards to help them get rid of unwanted pests. 

But you must not be careless around them; remember, these wasps are ambush attackers who hunt by paralyzing the insect prey with a fast and dangerous venomous sting. 

The sting can cause severe pain and can induce an allergic reaction in human bodies. 

Do Thread Waisted Wasp Sting Humans

Thread-Waisted Wasp Sting Pain Index

According to the Schmidt Sting Pain Index, a paper wasp sting has a pain level of 3. The thread-waisted wasp sting is also similar to that of a paper wasp. It will deliver almost the same degree of pain and discomfort to the victim. 

Thread-Waisted Wasp Sting Treatment

If you ever get stung by a thread-waisted wasp, you can get redness and mild swelling in the area. Immediately clean the wounded area with soap and water. 

You can apply a cold compress to the site as well. If you experience a severe urge to itch the injured area, use baking soda mixed with water to calm it.

Symptoms

The thread-waisted wasp venom is mild compared to more aggressive black wasp and blue wasps, so you may not experience extreme pain or severe swelling.

Here are a few symptoms:

  • Redness in the stung area.
  • Mild pain or a tingling sensation near the wound.
  • Sudden swelling.
  • Sudden urge to itch the wounded area.

Treatment

You can use the hacks mentioned above to treat a thread-waisted wasp sting. However, if the symptoms continue to appear for more than a day, consult a doctor immediately. 

Also, these attacks can trigger allergic reactions in your body. 

For example, if you face problems like a suddenly appearing rash, loss of consciousness, trouble swallowing, increase in heart rate, or swollen lips, immediately call an ambulance. 

For those who are severely allergic to insect bites, it is best to keep an insect bite kit with epinephrine around at all times because, in the worst case, the allergy could trigger anaphylactic shock.

Do Thread Waisted Wasp Sting Humans

Frequently Asked Questions

Do thread-waisted wasps sting people?

Thread-waisted wasps are a solitary species with a docile nature and rarely attack humans or pets. Most of these wasps use venom only to hunt their prey. 
Although they don’t aggressively defend their nests, they will attack in defense if you try to handle them. 

Where can you find thread-waisted wasps?

Thread-waisted wasps are found all over the world. In North America, about 125 species of these wasps are found, categorized into 11 genera.
The nesting starts in early July. You can easily spot these wasps near gardens and yards as farmers like to build favorable conditions in their yards for them to nest around them. 
In most cases, mud daubers and digger wasps build their nests on bald patches of ground with no plantation or grass near it.

Are there any wasps that don’t sting?

The Great Golden Digger wasps are one of the least aggressive wasps. The males don’t have a stinger and, therefore, will not sting under any circumstance. 
The females have limited venom, which they prefer to save for hunting. 
The black giant ichneumon wasp is also without a stinger. Its females have a long ovipositor but not stingers, and the males have neither.

Will dirt Dobbers sting you?

A dirt dobber is unlikely to sting humans. Even if it does, the symptoms might resemble a harmless sting. 
Their venom is mild, so the pain and swelling will be less compared to the bites of a paper wasp or yellow jacket wasp. 
Still, it is best to keep a safe distance and not try to mishandle these creatures.

Wrap Up

We hope after reading this article, you will be able to handle a thread-waisted wasp sting carefully.

While most of these bugs are non-aggressive and will not try to sting you unless you mishandle them, it is best to keep a safe distance and maintain your precautions.

Thank you for reading!

Reader Emails

In the past we have often received emails asking us to identify thread waisted wasps and whether they were dangerous in any way. Read on to see some of the pics and emails from our readers over the years.

Letter 1 – Thread-Waisted Wasp paralyzes Caterpillar

Wasp burying a worm
Location: Grants Pass, OR
August 4, 2011 12:57 pm
I took a series of pictures of a wasp digging a hole, burying a worm it dragged into teh hole and then covering the hole up. I know that the worm will be food for the larvae of this wasp, but I had never seen the process.
Are you at all interested in this series of photos? If so, I’d be happy to send them to you. I have included one as a sample.
Signature: Lucy

Thread-Waisted Wasp paralyzes Caterpillar

Hi Lucy,
This is a Thread-Waisted Wasp in the genus
Ammophila (see BugGuide), and it is carrying back a Caterpillar for its brood, not a worm.  If you want to attach a few more choice images, we can add to this posting.

Thread-Waisted Wasp seals nest

Of course, you’re right – it’s a caterpillar. I’m going to buy your book so I won’t be so casual about worm v. caterpillar!
I hope someone finds these pictures to be interesting. It’s so amazing what’s going on at our feet and all around if we’ll just stop a minute and take a look. Thank you for your site. I appreciate the work you do!
Lucy

Thread-Waisted Wasp inspects nest

Hi again Lucy,
Thank you so much for supplying additional images.  We believe your Thread-Waisted Wasp looks like this unidentified species in the genus
Ammophila that is posted to BugGuide.  It is from Oregon, but insects don’t really recognize borders identified by humans.

Letter 2 – Thread-Waisted Wasp

What’s this bug?
Location: Bermuda Dunes, CA.
May 6, 2012 11:58 pm
Hi,
I saw this guy in my back yard today. Black body and legs with a red abdomen. It looked like a very large ant but with wings. Almost an inch long. He was scurrying across the ground on this warm spring afternoon. He never flew. Just curious because we can’t seem to figure out exactly what he was. Thanks!
Signature: Jeff

Thread-Waisted Wasp

Hi Jeff,
This is a Thread -Waisted Wasp in the family Specidae.  We believe we may have correctly identified it as
Prionyx parkeri based on photos posted to BugGuide. On the genus page, BugGuide notes that the habitat is “Open areas from prairies and deserts to vacant lots and fields” and “Adults feed on flower nectar. Female wasps secure adult grasshoppers (Acrididae) as live, paralyzed food for their offspring. Prey is stored in a burrow, an egg laid upon it, and the burrow sealed.”  We suspect this is a female and she is searching for prey to provision a burrow for her offspring.

Thanks for the ID.  Now I know “he” was a “she!”  I hope she found what she was looking for.  We live in the desert of southern California near Palm Springs.  It is very warm and dry here now.  There are vacant fields and lots nearby, so she wasn’t too far from her habitat.
Jeff

Letter 3 – Thread-Waisted Wasp from India

Subject: Hey there, Bugman!
Location: Bangalore, Karnataka, India
April 28, 2013 1:49 am
I found this guy in a patch of wilderness in Bangalore, India. He was flying around, carrying little rocks to his little hole in the ground. I was wondering what bug this was? I was a little afraid to get too close, because I wasn’t sure if that was a stinger at the end of his body. I’m uploading two pictures, since only one of them properly shows his abdomen.
Signature: Meg

Thread-Waisted Wasp
Thread-Waisted Wasp

Dear Meg,
We apologize for not having the time to hunt out the species for this wasp, but we are relatively certain it is a Thread-Waisted Wasp in the family Sphecidae.  This series from BugGuide would support our speculation.  Perhaps your female Sphecid Wasp is beginning to seal this nursery burrow.

Thread-Waisted Wasp
Thread-Waisted Wasp

Letter 4 – Thread-Waisted Wasp from Australia

Subject: What is this?
Location: Whitsunday Islands, Queensland, Australia
January 11, 2014 9:08 pm
Hi
We saw this large black flying insect all over the beaches in the Whitsunday Islands. They were about 1.5 inches long, maybe a centimetre wide. They burrow into holes in the sand. They didn’t seem very interested in people, mostly ignoring us.
What on earth is it??
Thanks
Signature: Jenny

Thread-Waisted Wasp
Thread-Waisted Wasp

Hi Jenny,
We don’t believe we will be able to provide you with a species identification based on your photos, but we can give you a more general family and subfamily identification.  This is most likely a Thread-Waisted Wasp in the family Sphecidae, and we are basing this on the anatomy of the wasp in your images, specifically the narrow “wasp waist” as well as the burrowing behavior.  Furthermore, we believe it is in the subfamily Sphecinae.  The Brisbane Insect website describes the subfamily:  “Wasps in subfamily Sphecinae are usually black in colour, from medium to large size. They have the abdomen link with thorax with very slender cylindrical stalk-like petiole, i.e. the thread-waist. They predatory on Orthoptera, including grasshoppers and katydids. Females build nest for their young by digging long tunnel in sandy ground. “

Sphecid Wasp
Sphecid Wasp digging

Your photos are most interesting to us on a behavioral level of the subfamily rather than as images of a specific species.

Thread-Waisted Wasp
Thread-Waisted Wasp

Letter 5 – Thread-Waisted Wasp: Sphex lucae

Subject: Help! What is this bug?
Location: Riverside, California
August 15, 2015 8:56 am
We found this weird bug on our patio and we don’t know what it is. Is it a kind of wasp? We didn’t see any other ones. Can you tell us what is please?
Thanks!
Signature: Hope (6 yrs old)

Thread-Waisted Wasp:  Sphex lucae
Thread-Waisted Wasp: Sphex lucae

Dear Hope,
This is indeed a wasp, more specifically a Thread-Waist Wasp in the family Sphecidae.  These are solitary wasps and they are not aggressive.  We believe your individual is in the genus
Sphex, and though the genus is well represented on our site because of the Great Golden Digger Wasp and the Great Black Wasp, your lovely red and black individual is a different species, probably Sphex lucae, based on the images on BugGuide.  This is a new species for our site.  BugEric has an excellent description of this species.

Letter 6 – Thread Waisted Wasp

Subject: What kind of insect is this??
Location: Arizona
June 17, 2016 4:20 pm
Found this bad boy buzzing around the cab of my truck and it just wouldn’t leave, now i am very curious as to what it is and if it is dangerous because i was sure acting like it haha.
Signature: Mark V

Thread-Waisted Wasp
Thread-Waisted Wasp

Dear Mark V,
This is a Thread-Waisted Wasp in the family Sphecidae, and they are solitary and not aggressive.  It very much resembles the Great Golden Digger Wasp, but the coloration is wrong, especially in the face, so we believe it is a member of the same genus.  This image from BugGuide looks quite similar.  We will check with Eric Eaton to see if he can confirm our ID.

Eric Eaton Provides a Correction
Daniel:
I think the wasp in question is actually a female Prionyx foxi.  Great find if so, they don’t seem to be very common.
Eric

Ed. Note:  Here is the BugGuide page with additional images.

Letter 7 – Thread-Waisted Wasp

Subject: Bug id
Location: Virginia Beach VA
July 6, 2016 8:05 am
I am looking to identify this bug I have seen on my Threadleaf coreopsis. Can you help me figure out what this is and if he is a good bug? I am thinking some kind of thread waisted wasp.
Signature: Stacey Allin

Thread-Waisted Wasp
Thread-Waisted Wasp

Dear Stacey,
This is a Thread-Waisted Wasp in the family Sphecidae, but we are not able to provide you with a species identification.  Thread-Waisted Wasps are solitary wasps and they are not aggressive.  Adults take nectar, but females prey upon insects to feed to the young.  They are considered beneficial.

Letter 8 – Thread-Waisted Wasp

Subject:  Flying insect
Geographic location of the bug:  Shirley, NY
Date: 09/19/2017
Time: 12:48 AM EDT
Can you identify this bug I found on my flowers?
How you want your letter signed:  Diane L

Thread-Waisted Wasp

Dear Diane,
This is a Thread-Waisted Wasp in the genus
Ammophila.  According to BugGuide:  “Adults visit flowers. Larva feed on caterpillars and sawflies provisioned by the adult female.”

Letter 9 – Thread-Waisted Wasp caught on security camera

Subject:  What is this ????
Geographic location of the bug:  Lehighton Pa
Date: 09/20/2017
Time: 03:57 PM EDT
This flew up to my front porch and was recorded on our security system.
This is a still of it. In the video it flew off
How you want your letter signed:  Jerry

Thread-Waisted Wasp

Dear Jerry,
Your security camera recorded a Thread-Waisted Wasp in the family Sphecidae, and there are several species that use houses as places to construct nests.  Grass Carrying Wasps often nest in the tracks of sash windows and Mud Daubers frequently make mud nests in the eaves of homes.

Thanks so much Daniel !
Been looking forever.

Letter 10 – Thread-Waisted Wasp preys on Cutworm

Subject:  Digging in the dirt!
Geographic location of the bug:  Southern Nevada
Date: 10/25/2019
Time: 03:08 PM EDT
Your letter to the bugman:  While out to lay pavers in our yard we got to watch a fascinating insect we’d never seen before. We watched for some time as it dug in our soft dirt, buzzing in the hole, moving rocks (sometimes as large as it was!) and at one point it unearthed a grub of sorts! Biting it behind the head it held in… it didn’t appear to sting it, and eventually the grub ceased to move. For an hour we watched as our friend dig holes, and then moved on to another spot. On one hole we watched her start to fill it back in, going in to buzz excitedly, then back to digging. I have a couple of videos too, if you’re interested.
How you want your letter signed:  Sincerely, Kristi Shaffer

Thread-Waisted Wasp with Cutworm Prey

Dear Kristi,
This is a Thread-Waisted Wasp in the family Specidae, and the prey is a Cutworm.  The Wasp will not eat the Caterpillar.  Rather, the female Wasp has paralyzed the Caterpillar which it will bury and the paralyzed Caterpillar will provide food for the developing Wasp larva which will feed on the helpless, but living Caterpillar.  We believe we have correctly identified your Wasp as
Podalonia argentifrons thanks to images posted to BugGuide.  According to BugGuide:  “Larvae are provisioned with caterpillars exclusively from the family Noctuidae.” 

Thread-Waisted Wasp with Cutworm Prey
Thread-Waisted Wasp

Authors

  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

    View all posts
  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

    View all posts
Tags: Thread Waisted Wasps

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2 Comments. Leave new

  • The caterpillar appears to be in the genus Nadata, either N. gibbosa or N. oregonensis. Ammophila have been recorded using N. gibbosa as a host before.

    Reply
  • Thread-waisted wasps have built a nest on the shelf in my office. How can I remove the nest without killing the wasps?

    Reply

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