Are Spider Wasps Dangerous To Humans? Truth Revealed

Spider wasps look fearsome and have an intimidating reputation to boot. But are spider wasps dangerous to humans, or have they been unfairly maligned? Let’s find out

When added to the name of any insect, the word wasp immediately creeps out most people. But if you add the word spider on top, the effect is magnified!

Despite its name and threatening appearance, spider wasps feed on nectar and aren’t aggressive at all.

The spider wasp belongs to the Insecta class of the Arthropoda Phylum. These insects (they are wasps, not arachnids) are also known as pompilid wasps because they are part of the Pompilidae family.

Found all across the world, there are over 5,000 species of spider wasp spread across six distinct subfamilies.

These wasps get their name from their ability to capture and paralyze spiders, often twice their size, and use them as fodder for their larvae.

Are Spider Wasps Dangerous To Humans? Truth Revealed

What is This Bug?

Spider wasps are solitary insects. Each female works alone to create her own nest and rear her family instead of making a nesting colony like most bees.

Spider wasps are most often nectarivores. These charcoal-black flying bugs feed themselves by sucking nectar from flowers and overripened fruits.

Despite their daunting appearance, they are seldom aggressive since they don’t have a colony to defend.

The most commonly found species of spider wasps in North America is Cryptocheilus bicolor. Their trademark orange band on the abdomen and bright-colored wings and legs help to identify them quickly.

These wasps predominantly live in wetlands, heath, forests, and dense woodlands. In particular, you might often find them near tree barks and crevices inside them.

What Do They Look Like?

Spider wasps usually have visible veins (venations) on the wings, groves, and bands.

Most adult spider wasps have either amber or dark grey wings, yellow-orange legs, and a distinctive pair of antennae.

They also have a pair of spines on the hind limbs pointed toward the foot.

The wasps have three pairs of legs on the thorax and abdomen. Their body is tube-shaped and has plates covering both sides.

The female wasp is larger than the male. It can grow up to 1 inch in size, while male wasps usually do not extend beyond 0.5 inches.

Why Are They Called Spider Wasps

They are commonly known as spider wasps because of a very peculiar habit. Even though the adult spider wasp usually feeds off only nectar from flowers, the females also attack spiders.

They tranquilize them with a venomous sting and then drag them back to their nest. The paralyzed spider, still alive, become food for the wasp’s larvae.

This strange behavior only occurs when they are ready to lay their eggs, and infact they lay the eggs on the spiders’ abdomen itself.

Are They Harmful To Humans?

Spider wasps are known to tackle spiders twice their size and weight. However, their aggression is limited only to spiders and other spider wasps (during mating).

These wasps usually avoid bigger predators and humans and fly away when they detect danger. They rarely show threatening behavior towards humans.

Spider Wasp and Wolf Spider Prey

How Painful is the Sting of Spider Wasp?

Though most spider wasps are not very aggressive, a few species can have an excruciating sting. The tarantula hawk species has one of the most painful stings in the world.

Created by an entomologist named Justin O. Schmidt, the Schmidt Pain Index rates their sting at the highest value of 4. While a 0 rating indicates a painless sting, a 4 is the most severe sting in the world.

Schmidt described the sting of a tarantula hawk as the most excruciating torture of a burning sensation combined with a constant electric shock.

The only other insect rated with a more painful sting is the South African bullet ant, and the reason is that their pain can last a whole day, while that of the tarantula hawk lasts only a few minutes.

Are They Poisonous or Venomous?

Spider wasps have defensive stingers that inject venom to paralyze prey. This allows them to carry the spider easily into their nest.

The paralysis can last anywhere between a few hours to weeks. If the larvae do not hatch from the egg till then, the spider might be able to walk away from its ordeal.

Unfortunately, this is rarely the case.

The venom includes alpha and beta pompildotoxin that disrupts the functioning of the spiders’ cortical neurons, causing the spiders to go into a comatose state.

So, yes, they do have venom in their sting. However, this venom does not impact humans or other vertebrates who have different neurological setups.

Are They Aggressive?

Interestingly the spider wasp belongs to the same family as the dangerous Hornet Wasp, but their temperaments are entirely different.

Spider wasps are nervous flyers that seldom come in contact with humans. They are the least aggressive, especially towards bigger animals, unless someone provokes them.

If disturbed, they can deliver a very painful sting. However, if left alone, their aggression is solely focused on spiders.

What Can You Do if A Spider Wasp Stings You?

Spider wasps sting is harmless for those who do not have any allergic conditions to bug and wasp stings.

However, if you are allergic, it is important to report to the nearest medical center and seek help immediately.

An allergic reaction might result in an anaphylactic shock, so it is important to keep an epinephrin injection on yourself when you are around bees and wasps.

The normal localized reaction after being stung includes redness, swelling, itchiness, burning sensations, and hives in a few cases.

Severe symptoms can include nausea, vomiting, dizziness, etc.

Here is what you can do to mitigate the problem:

  • The first step is to immediately look for any stingers embedded into the skin and remove them with a tweezer or any such device but never with bare hands.
  • Clean the area well and disinfect before applying a cold pack to reduce swelling and localized rise in temperature.
  • Take Antihistamine or corticosteroid ointment application to reduce the discomfort.
  • Over-the-counter Acetaminophen should also be taken to reduce the pain.

Are Spider Wasps Dangerous To Humans? Truth Revealed

How To Control Them in Your Home or Garden?

Spider wasps are solitary insects; hence they are never seen in clusters or groups. Once identified, the easiest solution is just swatting them away or killing them.

However, it isn’t easy to find the nest of a wasp. If you find one, localized spraying with anti-wasp aerosols can help immediately remove the nest and the wasp.

Take care to do this at night since the wasps are inactive at that time.

Do not use any insecticides. Using pesticides in the garden can cause the death of naturally found beneficial insects such as beetles and ladybugs.

Frequently Asked Questions

What happens if you get stung by a spider wasp?

Spider wasp bite is not life-threatening for humans. It can only cause localized reactions like pain, swelling, hives, etc.
It can generally be treated with ointments, creams, and over-the-counter medications like analgesics and antihistamines.
In the rare instance of an allergic reaction or shock, its important to seek medical intervention immediately.
The most common sign of a severe reaction to a wasp sting is shortness of breath, extreme uncoordinated movement, rise in body temperature, hives, etc.

Do spider wasps bite or sting?

Spider wasps do not have claws or mouthparts to bite. However, they have stingers that they use to deliver extremely painful stings by injecting venom into the skin.
The Spider wasp sting can be excruciatingly painful and lasts anywhere between 3 to 5 minutes.

Where are spider wasps located?

Spider wasps are found all over the world. With over 5,000 species spread across six subfamilies, these insects are a common sight in most gardens, wetlands, and even amidst dry arid conditions of the deserts.

What is the fastest way to heal a wasp sting?

The easiest way to deal with the pain caused by a wasp sting is to remove the stinger, disinfect the area and follow it with an ice pack compression.
A cold compress can reduce the burning sensation and swelling caused by the sting. Follow it with a localized steroidal or antihistamine ointment.

Scary, But Not Aggressive!

With its fearsome-looking body, a spider wasp can be an alarming sight in your lovely garden.

However, these wasps pose little threat to humans and can be left alone.

If your garden is infested with spiders and other arachnids, welcoming a few spider wasps can even do your garden good. Thank you for reading!

Reader Emails

Spider wasps can leave behind a nasty sting. But while it will hurt humans for a bit, it won’t cause any permanent damage.

Many of our readers have been stung by these bugs in the past, read all about their experiences in the letters below.

Letter 1 – Spider Wasp (Tachypompilus ferrugineus) with Rabid Wolf Spider prey

 

a picture for you
I saw this wasp dragging the spider through my backyard. I live in
central NJ. The spider’s body was about an inch long and in think it’s called a Rabid Wolf Spider. Do you know what kind of wasp this is? Is the wasp going to eat the spider?
Pete

Hi Pete,
This Spider Wasp is Tachypompilus ferrugineus. It is not going to eat the Rabid Wolf Spider. The spider will be a food source for the larval wasps.

Letter 2 – Ichneumon

 

Striped antenna scavenger
Sun, May 3, 2009 at 8:09 PM
Hi Bugman,
I was in local park and saw this bug running around over leaves. It was moving its antennas over everything it ran over like it was trying to feel and detect food. I had never seen a bug quite like this and was wondering what it was. I scared it at one point and it flew away. Thanks and keep up the good work.
Inquiring Mind
Cary, NC

Spider Wasp
Ichneumon Wasp

Dear Inquiring Mind,
WE are relatively certain that this is a Spider Wasp in the family Pompilidae. According to BugGuide: “Adults are usually found on flowers or on the ground searching for prey.” This seems to accurately describe the behavior you witnessed. The doubt we are having has to do with the wings. BugGuide indicates: “Wings not folded flat on top of abdomen” and your specimen appears to have flat folded wings. There are 8 pages of genera listed on BugGuide, and our quick search did not provide any matches with striped antennae. We hope to get some input from Eric Eaton on this ID, and perhaps some reader can also provide a species or genus name for us.

Spider Wasp

Correction: Wed, 6 May 2009 17:36:40 -0700 (PDT)
Daniel:
The “spider wasp” is actually an ichneumon wasp:-)  Fooled ya!  Hey, everybody has been fooled by mimicry like this at one time or another.  Spider wasps very rarely have banded antennae, but the tips of the antennae are sometimes a different color.  Many ichneumons and sawflies do have banded antennae, however.
Eric

Letter 3 – Spider Wasp

 

Sphex nudus?
Location: Hawthorne, CA
August 20, 2011 6:02 pm
Hi,
I think, thanks to a hint that Eric Eaton posted on bugguide.net, that I have this properly identified as a Sphex nudus (Katydid wasp). Can you please confirm?
Signature: Thanks, Anna Carreon

Spider Wasp

Hi Anna,
Goodness, you have sent us a few tough identifications, and though we spent some time trying to research identities, we didn’t have much luck.  We are not sure which comment attributed to Eric Eaton has caused you to believe this is a Katydid Wasp, but we are not certain the Katydid Wasp is found in California based on the BugGuide distribution map.  There are similarities between your individual and the Katydid Wasp, and it is possible it is a similar looking relative that is not represented on BugGuide.  We wish you had a photo that showed the face better.  We believe this is most likely one of the Spider Wasps in the family Pompilidae, however, we were unable to find a match on BugGuide.  These are the family characteristics that have influenced our opinion:  “Typically dark colored with smoky or yellowish wings; a few are brightly colored.  Slender with long and spiny legs, hind femora typically extending beyond tip of abdomen.   Tibiae of rear legs have two prominent spines at apex (distal end, next to tarsi).”  We will contact Eric Eaton to try to get his opinion.

Spider Wasp

Eric Eaton provides Spider Wasp identity
Daniel:
Your first instincts are correct.  This is a spider wasp, Episyron coterminus posterus:
http://bugguide.net/node/view/146243/bgimage
Nice images, too.
Eric

Hi Daniel,
I’m sorry to have sent you tough identifications.  You know, as I continued looking at distribution maps and the faces of the Katydid Wasps, I started to doubt my identifications.  I figured I’d just wait to hear from you.  Thanks very much.  If you have a chance, will you please also thank Eric Eaton for me?
As I read more on this wasp, I’m surprised at how long it held still for me – almost 5 minutes.  I really do have to think about getting a little better camera.
Anna

Letter 4 – Wasp Spider from Greece

 

Subject: What spider is that?
Location: Greece, Edessa
October 13, 2013 6:24 am
Greetings to the community…i found this spider in my garage and i have been wondering if its poisonous or not.
I am living in northen Greece, Edessa
I just want to know if i have to worry for more or not…cause i have never seen one like this! and Scout guy.
Thank you!
Signature: George Samouilidis

Wasp Spider
Wasp Spider

Hi George,
Your spider is a harmless Orbweaver,
Argiope bruennichi, and it is commonly called a Wasp Spider.  According to UK Safari:  ” It’s a native spider of Mediterranean areas, and has only recently colonised England.  Despite the warning colouration this is not a dangerous species.  The wasp-like appearance is probably defensive, to deter predators.”  The Spiders of Northwest Europe has some beautiful photos of the Wasp Spider. 

Letter 5 – Spider Wasp: Tachypompilus ferrugineus

 

Subject: What insect is this?
Location: East Coast- Balt, Md
August 13, 2014 12:45 am
Found this suck roaming my kitchen floor at 3am?
What is it?
Signature: Dez

Spider Wasp:  Tachypompilus ferrugineus
Spider Wasp: Tachypompilus ferrugineus

Dear Dez,
This Spider Wasp,
Tachypompilus ferrugineus, appears to be dead since you have also included a ventral view with its legs sticking up in the air.  Since you found it roaming, we are guessing it died at your hands.  We believe living Spider Wasps, like this one pictured on BugGuide, are much prettier than dead ones. Spider Wasps are not aggressive toward humans, and in an effort to educate you and others on the importance all living creatures play in the complicated web of life on our planet, we are tagging this posting as Unnecessary Carnage.

Dead Spider Wasp
Dead Spider Wasp

Letter 6 – Spider Wasp stings woman in Australia

 

Subject:  Flying stinging bug
Geographic location of the bug:  Perth Western Australia
Date: 03/04/2018
Time: 07:52 AM EDT
Your letter to the bugman:  My mother has been stung by this and I have no idea what it is
How you want your letter signed:  Stinging bug

Spider Wasp, we believe

The antennae and the spines on the hind legs lead us to believe this is a species of Spider Wasp in the family Pompilidae, but alas, we have not had any luck locating any images online that look like your individual.  Perhaps one of our readers will have better luck than we have had.  According to Brisbane Insects:  “Most of the Spider Warps [sic] are orange and black, black and grey/white markings or just black, i.e., the very strong warning colours. They usually have tinted wings, smooth and shiny body. Their hind-legs are long and always have two prominent spurs. They tend to coil their antennae. They usually hunting on ground with the characteristic wing flicking movement.  Females have very powerful sting.”

Leave a Comment