Tarantula hawk wasps are a subtype of solitary insect that live in underground burrows. They are known for their size and intensely painful stings. There are several species of this wasp under the genus Pepsis, but all are generally referred to by the above name.
While they aren’t unusually aggressive insects that require pest control measures, you’ll want to exercise caution if you encounter one on your property.
Here, we’ve outlined all that you’ll need to know about “tarantula killers,” including their distribution range, typical diet and behaviors, and what to do if you spot one of their telltale burrows close to your home.
What is a tarantula hawk wasp?
Tarantula hawk wasps are burrowing insects that do not nest or establish colonies, as you would expect from other similar species. They have a blue-black shiny exoskeleton and orange or amber-tinted wings. When paired with their two-inch maximum length, these traits make them almost instantly recognizable.
Here are some fast facts about tarantula killers, compared to other common wasp varieties:
| Factor | Tarantula hawk wasp | Paper wasp | Yellow jacket | Mud dauber wasp |
| Average size | 1 ½ to 2 inches | Up to ¾ inch | Up to ½ inch | ½ to 1 inch |
| Nesting behavior | Solitary, in burrows | Colonies, in gray nests made from chewed plant fibers | Colonies, in the ground, rotten wood or dense foliage | Solitary, in pipe-shaped or rounded dried mud structures |
| Color | Blue-black | Black or brown with yellow stripes | Black and yellow stripes | Metallic blue, black or black and yellow |
| Wings | Orange or amber | Black | Opaque amber brown | Amber brown |
| U.S. Range | Primarily in southwestern deserts; few in Southeast and northern states | Throughout all 50 states | Throughout all 50 states | Throughout all 50 states |
| Aggression towards humans | Only if provoked | If provoked | Yes, if you’re close to their nests | Only if provoked |
Why are they called “tarantula killers”?
Mature tarantula hawk wasps are nectarivores, meaning they get all their nutrients from nectar. Like the Monarch butterfly, they primarily feed on and pollinate milkweed.
The “tarantula killer” name comes from the species’ reproductive cycle. Once a female tarantula hawk is ready to lay her singular egg, she goes on the hunt for a suitable host for her offspring. The full grizzly process looks like this:
- Once she spots a viable tarantula, a female tarantula hawk will land on the ground near it and engage. This usually begins with the wasp cautiously circling its target while slowly getting closer.
- These movements confuse tarantulas due to their poor vision. Once close enough, a tarantula hawk will flip onto its back to get underneath the unsuspecting host.
- When in range, it delivers a disabling sting between a leg joint and belly plate of the spider to paralyze it.
- The venom takes effect within seconds, allowing the attacker to drag it to either its own burrow or the wasp’s.
- Now concealed, the tarantula hawk lays a single egg on the tarantula’s abdomen.
- After three to four days, the larva hatches and uses sharp mandibles to bore into the still-living tarantula.
- It begins to feed, targeting less vital organs in its host, which is designed to keep it alive for as long as possible.
- Once the tarantula has been consumed, the larva spins a cocoon and pupates into a mature wasp in two to three weeks.
A female wasp’s lifespan is only a few months, but it will conduct this cycle up to a dozen or more times once mature.
Are tarantula hawk wasps aggressive towards humans?
No, tarantula killers are not aggressive towards humans. Very few instances of stings have been reported. In fact, the wasps are docile when foraging for nectar or mating. They will only ever attack humans if directly handled or swatted at, or if they feel their burrows have been threatened.
It could be easy to interpret certain behaviors as aggression. Males perform complex mating flights in the late summer months and into fall (August through October) which often involve intercepting prospective partners mid-air. If you’re standing by a milkweed plant or another tall flowering plant, you could potentially be interrupting this ritual.
Where are tarantula hawk wasps located?
In the United States, tarantula hawk wasps are located primarily in the southwestern desert regions, such as Arizona, New Mexico and Nevada. They thrive in hotter, dryer climates, but have been spotted in northern Utah and Colorado.
Other sightings include Florida and the Carolinas, with very occasional instances reported in the Midwest and Pacific Northwest.
What to do if you’re stung by a tarantula hawk wasp
By all accounts, tarantula hawk wasps have one of the most painful insect stings in nature. There isn’t much to be done for first aid aside from pain management in most cases. Only females sting, but their stinger can be up to ¼ inch long and may deliver multiple stings.
You’ll have to brace for intense pain if you’re unlucky enough to get stung. Luckily, this dissipates after five to 10 minutes. Applying a cold compress can reduce swelling and mitigate the pain. If you experience any of the following symptoms, seek out medical attention:
- Continued swelling after 24 hours
- Hives
- Red streaks radiating from the sting location
- Difficulty breathing or any respiratory distress
- Elevated heart rate after pain has subsided
Entomologist Justin Schmidt compiled data from 78 species’ stings and rated them on a scale from one to four, with four being the most painful. Tarantula hawks were squarely in tier four, with Schmidt himself stating that the best course of action is to “lay down and scream.”
| Schmidt Scale rating | Insect | Sting comparison |
| 1 | Fire ant | Sharp and sudden, like a localized electrical shock |
| 2 | Yellow jacket or honey bee | Burning sensation |
| 2.5 | Trap-jaw ant | Like a rat trap snapping shut on a fingernail |
| 4 | Tarantula hawk wasp | Intense and blinding, like a severe full-body electrical shock |
| Bullet ant | Like walking on hot coals with a nail in your heel |
While tarantula hawk wasps are technically listed on the same tier with bullet ants, the latter is noted as being the most painful of the two stings.
Tarantula hawk wasp nests
One of the primary triggers for tarantula hawk wasp aggression is encroachment into its territory. In short, they are more likely to attack if they feel directly threatened.
Most often, they nest in one- to two-inch holes in sandy or dry soil. These wasps either dig their own burrows or reuse tarantulas’ own homes once they’ve subdued a host for their young. They may also repurpose burrows dug by other insects.
What to do if you encounter a tarantula killer nest
It is best to avoid directly interacting with a tarantula hawk nest if you can reasonably do so. These insects are solitary and generally not aggressive towards humans. If they have nested near your home in the past, removing food sources like milkweed or inspecting for and removing tarantulas from your property could be worthwhile preventive measures.
When to call a licensed pest professional
Generally, pest control experts have a hands-off view of tarantula hawk wasps if they’re not an immediate threat. As solitary insects with limited aggression towards humans, the risk of getting stung is often not worth your direct interference.
But if you are concerned and want an expert to determine a course of action, an inspection never hurts. “You will want to call a pest pro if you’re seeing activity near entryways, patios, play areas, or other places where people or pets spend time,” says Chuck Hamlin, the president at Evergreen Lawn & Pest Control in Florida.
Contacting a top pest control pro or hiring an exterminator isn’t usually needed but could be a recommended course of action if you, children or pets are regularly close to a nesting site.
Frequently asked questions
When are tarantula killers most active?
Tarantula hawks are most active during the daytime in the hot summer months. Females fly solitary routes closer to the ground while searching for tarantulas to host their young. Otherwise, both male and female wasps often cluster around milkweed as they forage for food.
Can tarantula hawk wasps reproduce asexually?
Yes, tarantula hawk wasps can reproduce asexually. Unfertilized eggs become male offspring, while all fertilized eggs are female. This influences a mother’s choice of tarantula, as larger hosts are often reserved for slightly larger female larvae.
What is the difference between a male and a female tarantula hawk wasp?
While you wouldn’t often get close enough to tell, male and female tarantula hawks have some well-defined differences. Males have straight antennae, while females of the species are slightly larger with curled antennae. Perhaps most importantly, males cannot sting you.
What eats tarantula hawk wasps?
There are relatively few instances of tarantula hawk wasps being preyed upon. However, roadrunners are the most cited predators. In the rare instances people have spotted, these birds avoid getting stung by smashing the wasps on the ground to break the stingers before finishing their meal.
Are tarantula hawk wasps active pollinators?
Yes, tarantula hawks are active and important pollinators of milkweed. If you have this in your yard and live in a desert or hot climate, there’s a good chance you could see these wasps near or on your property.
Do tarantulas ever escape from tarantula hawks?
This happens occasionally but is more an exception than the rule. Tarantulas sometimes escape, but tarantula hawks are very successful when hunting for a host. And when they’ve been stung and the wasp has laid her eggs, it’s a death sentence for the tarantula.