Did you know that there is a wasp that lays eggs in spiders and uses them both as host and food for its larvae? In this blog, we cover this amazing tiny wasp that paralyzes and enslaves huge spiders for its benefit.
Spider wasps are parasitoid wasps whose hosts are spiders forced to incubate the wasp larva laid by a female wasp inside the abdomen of spiders.
The larva feeds on the spider, leaving behind the vital organs. Then, the poor spider is forced into making a cocoon web for the larva to pupate into adult wasps. Ultimately, they kill the paralyzed spider.
What Are Spider Wasps?
Spider wasps are solitary wasps that belong to the Pompilidae family. There are nearly 5,000 species of wasps in this family.
They are mainly predators of spiders and feed on their larvae. But some species can kill and eat adult spiders.
Other species also live as parasites on smaller spider wasps.
As these wasps are solitary, they do not form colonies that need protection. Thus, they aren’t aggressive.
They are active during summer and live in forests, woodlands, wetlands, and even urban areas. Since the adults are nectarivores, you will find them flying around flowers for most of the day.
These wasps live on all continents except Antarctica.
What Do They Look Like?
The most commonly found spider wasps are the Cryptocheilus bicolor.
These are bigger than most other wasps and have a broad orange band on their abdomens. Their females can be as long as 1.35 inches.
The rest of the wasp’s body is black, and its wings are orange colored. The legs are of an orangish-yellow color as well.
The wasps keep their wings down but tend to flicker them when hopping and running. Their long legs allow them to run fast on the ground.
What Do They Eat?
Spider wasps actually do not feed on spiders as adults. They feed on nectar from flowers, juice from overripe fruits, and honeydew from aphids and similar arthropods.
As larvae, however, they feed on spiders, and the way they hunt and eat them is how they got their names.
The adult wasps have developed several tactics in order to catch live spiders, paralyze them and drag them to their nests so that the larvae can feed on them.
For example, some species of spider wasps are known to bite the legs of hairy spiders, injecting venom and paralyzing them.
Tarantula Hawks prefer to attack the abdomen of tarantulas, where injecting venom is easier and reaches their nervous system directly.
Reclinervellus nielseni wasps have scales on their feet that help them to walk on spider webs and attack the spider at the center of the web.
Why Do They Attack Spiders?
They attack spiders mainly for two reasons; to incubate their eggs and as food for their larvae.
Spider wasps lay their eggs about a foot deep beneath the earth in their underground nest. When the eggs hatch, they need to have food readily available to survive.
So these wasps have devised an innovative solution to this problem – they use host spiders to lay their eggs, and those spiders become the food for the larvae as well.
However, before we get ahead of ourselves, let’s first explain how a small wasp is able to overpower a predator as feared as a spider.
Spider Wasp Adaptations To Hunt Spiders
Spider wasps are bigger than others of their species but smaller compared to the spiders that they hunt (such as tarantulas).
A typical tarantula hawk might reach about 2 inches in length, whereas a tarantula would be bigger than five inches.
However, this does not deter the wasps from attacking and hunting spiders because they have evolved defenses that make any spider attacks futile.
For example, these wasps have hard exoskeletons which the spider cannot pierce in order to inject its venom.
Moreover, they have long legs and are very fast movers. There is speculation that their quick movements confuse the spiders they hunt, which is why they do not put up a lot of fight.
Thirdly as winged insects, spider wasps clearly have the advantage of flying up or down if the spider tries to do something.
For example, most spider wasps are able to fly straight up several feet when needed.
Some of them have claws on their legs which help to hold the spider and carry it back to their nest.
Here is a video of this fight:
How Does The Wasp Attack the Spider?
The egg-carrying female wasp moves under the spider from the back while lying on her back in order to reach the abdomen.
The abdomen is the most vulnerable spot for a spider and has direct connections to its central nervous center.
She then pierces the spider’s abdomen with her stinging mouthpart, with the objective of paralyzing it.
The wasps use two mechanisms to do so. Firstly, the sting itself generates pain, making them temporarily paralyzed.
Secondly, the venom they inject into the spider causes permanent damage to their nervous system, leaving the body paralyzed.
Lastly, some species of spider wasps often bite off the hind legs of the spiders so that they cannot move, incapacitating them for life.
After all this, the spider is nothing but a zombie that is living and can emit feces but not move any of its body parts.
The wasp then drags the spider back to her nest. Spider wasp nests usually have multiple chambers, each one meant for one egg and its host insect.
Upon reaching the nest, the spider wasp leaves the spider outside, goes inside the nest, and checks it. Then it comes out and drags the spider in and lays its egg in the spider’s body.
How The Spider Becomes Food
In a few days’ time, the eggs begin to hatch from the spider’s body, and the larvae come out. The spider is ripe for eating at this point, still alive and fresh.
The larvae start feeding on the spider but are careful not to eat the vital organs until the very end, making sure that the spider lives the worst possible nightmare in its final days.
Reclinervellus Nielseni Enslaves Spiders To Build Webs for Them
As if laying their eggs on them and eating the spider alive was not enough, one particular species enslaves their host spiders to build their cocoon for them before killing them off.
The Reclinervellus nielseni species of spider wasps attack the arachnid Cyclosa argenteoalba, making them their hosts.
These spiders build two types of webs; one to trap insects they prey on, and another called the resting web, which does not bear the sticky threads that help catch the prey.
This web is essentially meant for the spider to rest (talk about holiday retreats!)
Reclinervellus nielseni wasps are able to walk on spider webs. They sting these orb weaver spiders, which keeps them alive but makes them incapable of moving.
Next, they take advantage of the size of the spider to incubate their larvae. Once the larvae of the wasp hatches, they start feeding on the fluids inside the spider’s body.
As the larvae reach pupation, they alter chemicals inside the host spider’s brain that change their behavior.
These mind-altering chemicals cause the orb-weaving spiders to make one last safe web or cocoon structure for the larvae to pupate.
And as a final act of subjugation, the larvae then kill the spider before pupating in the cocoon prepared for them by those very spiders.
Frequently Asked Questions
Are spider wasps harmful to humans?
No, spider wasps are solitary wasps and thus do not have colonies to defend. So, they are generally not aggressive to species other than spiders.
However, spider wasps have stingers, and if a human gets in their way or irritates them, the wasp sting can be very painful. In fact, their stings are recorded as one of the most potent ones in the world.
Do wasps lay eggs in tarantulas?
Yes, tarantula hawks a species of spider wasps that paralyze tarantulas to lay their eggs.
They do this by stinging tarantulas below their abdomen and biting off their hind legs, making them incapable of moving.
Then they lag eggs inside them, which hatch to feed on the spider itself.
What happens if you get stung by a tarantula wasp?
Tarantula hawks are not as dangerous as the tarantula itself to humans because they do not inject us with life-threatening venom.
Moreover, they rarely sting you as they are not aggressive. Unfortunately, if you do ever get stung, the tarantula hawk’s sting is considered one of the most painful in the world.
For at least 5-10 minutes, you will be totally incapacitated and most likely lying on the ground screaming. After that, there might be redness and swelling. These will subside in a few days.
If you are allergic to wasps or any chemical they secrete, then the sting can be very dangerous.
How painful is a spider wasp sting?
Wasps are known for their painful stings. The sting of a spider wasp, such as a tarantula hawk wasp, is unbearable. On the Schmidt pain index, it is the number two most painful sting in the world.
A skin-soothing gel might help relieve the pain. Spider wasp stings are not known to cause any skin damage unless you are allergic to them.
Spider wasps are known for enslaving spiders for their benefit. Their adults paralyze spiders almost twice their size and use them to incubate their eggs.
Their larvae feed them, and some even get them to build cocoons for them! Thank you for reading.
Spider wasps are amazing creatures, for the absolutely frightful death they give to some of the most feared creatures in the world – the spider.
Several of our readers have checked in with us over the years, asking us to identify wasps that are fighting death battles with spiders in or around their homes.
Samples some of these letters to see the clinical yet gruesome way in which these wasps battle with spiders.
Letter 1 – Spider Wasp from Australia
Spider Wasp: Pompilidae family
Sat, Oct 25, 2008 at 8:25 PM
This wasp was scurrying up a gum tree with a large spider for lunch.
See http://www.geocities.com/ brisbane_wasps/YellowAntWasp.htm for more information about this predator.
East Coast Australia
Nice to hear from you again. Thanks so much for helping to expand our new What’s That Bug Down Under? portion of our website. By the way, adult Spider Wasps don’t eat spiders. The spiders are food for the wasp larvae.
Letter 2 – Spider Wasp and Prey in Argentina
Red wasp-like insect that kills spiders
January 23, 2010
I need help identifying the insect in the photo. It was the length of an index finger, bright red with black stripes. It was dragging along a dead (?) furry spider. I need to know if it’s dangerous to humans, it was at the Botanical Garden where I do volunteer work year-round. It’s summer here in Buenos Aires, Argentina, and it’s normal to see more insects (and bigger) than usual, especially in the Botanical Garden (I do volunteer work with cats abandoned in the Garden). The Botanical Garden has a lot of exotic plants found nowhere else in the city. Should I be worried about this bug? I’d appreciate any info you could give me.
Botanical Gardens, Buenos Aires, Argentina.
We love your letter and we wish your photograph wasn’t so blurry. Perhaps your boss will pay for a photography class (shameless self promotion since we teach photography) and then you will better be able to document the wonders of the natural world at the Botanical Gardens. Please bear with us as we might get a little bit preachy here since we finally connected with the world yesterday and saw Avatar in 3D. The film profoundly affected us and we thank James Cameron for spreading the word about the need for preservation, the horrors of greed and war and violence, the fragility of our world, the interconnectivity of all things, and the elusiveness of unobtainium. With that said we will now try to answer your question. In a most general sense, this is a Spider Wasp in the family Pompilidae, though it will take us some time to try to identify the exact species. We do not get many letters from Argentina, and we are not sure if there are comprehensive websites devoted to Argentine insects. The filmic experience of Avatar has made us sensitive, so we might sound harsh when we ask “Did the Spider Wasp try to sting you and drag you back to its burrow to feed its young?” We suspect your answer will be no, so you have nothing to fear. The Spider Wasp only wants to provide for her progeny, and she has no desire to sting people. However, if she is molested, she may sting to defend herself. Spider Wasps are often very specific about the species of spiders they prey upon. Adult Spider Wasps feed upon nectar, which is another reason the botanical gardens are an attractive habitat for them. Based on the coloration and pattern, we suspect your wasp might be in the genus Tachypompilus, which BugGuide indicates is transcontinental for North America. BugGuide also indicates they prey upon Lycosids, Wolf Spiders, which is consistent with the furry spider description of your letter, though we could never hope to get an identification of the spider from your photo. Tachypompilus banksi might be the wasp in your photo, and we found a lovely photo posted online on the Insectarium Virtual website. The site has this information: “From the observations made known to hunt big spiders Lycosidae, Pisauridae and Sparassidae. The spider is captured by the jaws and dragged by the female. The construction of the nest sites are quite varied: cracks in rocks, hollow logs, cracks in walls or under stones. The nests are accumulations of powdery earth where the female buries the spider digging depressions of about 2 cm deep and only inches apart from one another (multicellular nest, according to Genise). The wasp builds the cell after the spider hunt.” Google provides a translation from Spanish. We are also intrigued with your volunteer job with abandoned cats in the Botanical Gardens. We can’t help but wonder if the cats are encouraged to hunt rats or if your work involves relocating them.
Thank you for the prompt reply! I apologize for the quality of the picture- I was feeding some cats, leaning over to put down a bowl of Cat Chow, when I turned around and there they were, inches from me face! I dropped the bowl (you can see kibble on the floor in the pic) and ran for it since I am extremely allergic to insect bites and these insects were hands down the biggest I’ve ever seen while volunteering in the Botanical Garden. I borrowed a phone with a camera from a passing tourist, and took the photos as far away as I possibly could, while still shaking a bit. That is why the photo is of such poor quality. I have to say the wasp was minding its own business and never noticed me at all. It was having some trouble dragging the spider up the side of a wall, the spider kept slipping off and falling.
The Botanical Gardens in Buenos Aires, Argentina, were designed and donated by famous Argentine architect Carlos Thays back in the 1800s. Here is the Wikipedia article on it: http://en.wikipedia.org/wiki/Buenos_Aires_Botanical_Garden Sadly, the article is full of innacuracies. Security in the Garden is minimal, so cats are abandoned there on a daily basis. The Park doesn’t contribute any funds towards the care of the cats, which were as many as 300 when the volunteers started their work there. We have managed, through intensive adoption campaigns and castration operatives, to keep the number down to about 100 cats, in spite of the new cats abandoned there every day. The Pasteur Institute does not contribute to their care at all. The Park also suffers from lack of government funding, so maintenance of the grounds and buildings is minimal.
Which brings me back to my original question. I want to avoid disturbing this kind of wasp when I go to the Park to feed the cats, provide basic veterinary for them, and neuter and arrange adoptions. How do I avoid its habitat completely? I know I should avoid cracks in rocks, hollow logs, cracks in walls or under stones. Is there anything else I should know about avoiding this wasp completely? And what about Wolf Spiders? If the wasp had caught one, it means that they live in the Park too. How do I avoid running into them?
Thank you so much for all your help.
Thanks for all the additional information. You went through so much trouble to get the photo that we feel badly about commenting on the quality. Cellular telephones are notoriously poor in the quality of their photos, but they are such a wonderful convenience. The spider, according to one of the links might also be a Huntsman Spider or a Fishing Spider. Some tropical Huntsman Spiders are reported to be poisonous, but the bites of Fishing Spiders and Wolf Spiders are not considered dangerous, though all spiders have venom. The Spider Wasps are not an aggressive group either, and they will not attack you. Sadly, other than living in a plastic bubble, there is probably no way to avoid them entirely. Thanks for the clarification on the cats. We would imagine that 300 cats at the gardens might become quite a nuisance, not to mention that once the rats are caught, they might turn to birds and lizards. We love cats, but they can upset a natural ecosystem, though the Botanical Gardens are hardly be considered natural. Have a wonderful day.
Letter 3 – Spider Wasp from Australia
Subject: Huge Waspe
Location: Adelaide, Australia
April 2, 2014 7:28 pm
I walked outside and felt a pain in my foot and saw this huge thing guarding the bin. Its the biggest I have seen in Adelaide – what is it a potter wasp?
Signature: Andrew Perrott
We find it amusingly ironic that the “huge thing” which is the “biggest [you] have seen in Adelaide” is also one of the tiniest images we have ever received for identification purposes. We would love to post a larger version of this image of a Spider Wasp if you have one and can provide it in a subsequent email.
Yes i figured out its a spider wasp through google – we have never seen one like this here
Thanks so much for attaching a higher resolution image.
i no have a red itchy foot – i am not sure what it did to me, either bit me or stung me
We would suppose you were stung.
Letter 4 – Spider Wasp
Subject: Zombie Wasp?
Location: Household basement of Pueblo, Colorado
June 25, 2016 7:27 am
Found this little guy in my grandmothers basement this morning. Now i’ve never been much of a bug enthusiast until I found this little guy and here is why. After flying through several cobwebs he tired out and hit the floor. After which my grandmother proceeded to try and kill it by stepping on it. after 4 attempts with a steel toe boot the creature revives itself after every attempt and walks off seemingly unscratched. The insect has a jet black body and dark blue wings with a body type very similar to a wasp. Though the actual head of the creature looks to be more like a fly. The insect also has 2 antennas that are curled at the ends. Any ideas about this small zombie?
Signature: Paranoid Captor
Dear Paranoid Captor,
This is a Spider Wasp in the family Pompillidae, and it might be one of the Tarantula Hawks, perhaps Pepsis mexicana which is pictured on BugGuide.
Letter 5 – Spider Wasp
Subject: Help identifying this insect
Location: Greater DC area
July 5, 2016 8:04 am
Hi there – we have been seeing these around our home, just the last few weeks (so starting in mid-June). Not a lot of them but still… Can’t decide if it’s a wasp or if it’s a Mydas Fly variety or…?
The lighting isn’t great – i couldn’t get him to cooperate – but the body detail is pretty good. His legs and abdomen are both this red color but his wings are black.
We live in the greater DC area, by the way. We live out in farmland area, with both some small suburbs and some wetlands nearby.
This is a Spider Wasp in the family Pompilidae, and we believe it is most likely Tachypompilus ferrugineus which is pictured on BugGuide. Spider Wasps are not aggressive, but they can sting.
Letter 6 – Spider Wasp: Entypus unifasciatus
Location: Skippers, VA.
September 12, 2016 10:04 pm
I found this in our woods in southern Virginia July 30th. It was constantly moving it’s wings and legs while sitting on this leaf. The colors almost look neon orange to me on it’s antennae. I’m new to photography so I hope this photo is okay. Can you please tell me what kind of bug it is?
We have identified your beautiful Spider Wasp as Entypus unifasciatus thanks to this BugGuide image. Female Spider Wasps provision nests with paralyzed Spiders as food for her brood. According to BugGuide: “This species is a typical late summer-early Autumn species in the east (nominal subspecies). July-September (North Carolina). In Ohio (and probably most of the northeast) some adults appear in late June, but most in early July. Most females are seen provisioning from mid-July to September. Out of all individuals seen from Ohio the peak in numbers of captures was from the last half of August.”
Letter 7 – Spider Wasp from Egypt
Subject: A bug
Location: Cairo, Egypt
August 11, 2017 12:54 pm
It is beautiful
We wish your image had better resolution. This appears to be a Spider Wasp in the family Pompilidae. It might be Cyphononyx bretonii which is pictured on Wasp Web where it states that it is found in Egypt as well as many other parts of Africa.
Letter 8 – Spider Wasp stunned by water, not killed by bug spray
Geographic location of the bug: Lincoln Nebraska
Time: 11:38 PM EDT
Your letter to the bugman: This buzzed by my sidters house today and I’ve never seen anything like it. Is it dangerous? They have kids and pets to keep safe.
How you want your letter signed: Concerned Sister
Dear Concerned Sister,
The time for your concern is long passed since it appears the Spider Wasp in this image was already dispatched with some type of spray that formed puddles around its body. Spider Wasps are not aggressive, though the might sting if carelessly handled. They are considered beneficial as they help to keep Spider populations in check. Many insects accidentally enter the home, and the best way to remove them alive is to trap them in a glass, and then slip a postcard between the glass and the surface so the insect can be safely transported outside. We believe the Spider Wasp in your image is Tachypompilus ferrugineus based on this BugGuide image. Here is an image of a Spider Wasp with its prey. Because we feel this harmless Spider Wasp was dispatched unnecessarily, we are tagging this posting as Unnecessary Carnage.
Letter 9 – Spider Wasp and Prey
Subject: Is this a spider wasp?
Geographic location of the bug: Conyers GA
Time: 04:07 PM EDT
Your letter to the bugman: Just wondering what type of bug this is. It was dragging a very large spider as it went along.
How you want your letter signed: Belinda
This is definitely a Spider Wasp. Based on this BugGuide image, it appears to be Entypus unifasciatus. The prey appears to be a Fishing Spider in the genus Dolomedes, and according to BugGuide: “Females dig a burrow that ends in a terminal chamber off of the side of a mammal burrow or large crack in the ground. The serrations on the hind tibiae are used to aid the movement of soil out of the burrow entrance. The position in which the egg is laid is unknown. Larvae feed on one large spider and, as in all Pompilids that have one generation per year, overwinter as pupae.” Most images of this Spider Wasp are with prey that are Wolf Spiders like this BugGuide image, but Fishing Spiders surely constitute “one large spider.” Perhaps an expert in Spider Wasps will be able to provide comments regarding the prey.