The tarantula hawk (Pepsis formosa) is actually a spider wasp that can grow up to 2 1/2 inches long with a 4-inch-wide wingspan. This one had a beautiful blackish-blue, metallic body with vivid, bright orange wings. Some have shiny blue/black wings that match its body. It has long black antennae and six velvety black legs with hook-like claws on the ends.
As the name indicates, they prey on tarantulas, which they need as hosts for their larvae. (I have only seen one tarantula on my property in the six plus years we have lived here).
Only the females sting. She will fly low to the ground looking for spiders. When she finds a tarantula's burrow she will disturb the web, mimicking trapped-prey. When the tarantula emerges to inspect its web, she will sting and paralyze it. She will then drag the tarantula back into its burrow, lay a single egg on its body and then cover over the opening to the burrow.
When the egg hatches, the larva will feed on the still-living spider, avoiding the vital organs in order to keep the host alive as long as possible. After approximately three weeks to a month, the larva will emerge from the now-dead tarantula's body.
Adult tarantula hawks feed on pollen and nectar from flowers, and juice from fruits and berries. They seem to be especially attracted to milkweed, soapberry trees, and mesquite trees. Males live approximately two months or less; females can live longer.
Although the tarantula wasp is not aggressive and stings are relatively rare, it is reportedly one of the most painful stings of any insect in the world. The stinger is a fierce 1/3 of an inch long. The pain is said to be absolutely excruciating and so debilitating that you can lose control of your body. If you get stung, it is recommended that you lay down as quickly as possible to avoid stumbling and falling and causing further injury. An intense, burning pain will last for about 5 minutes. You may experience swelling and soreness around the area for a few days – but it will pass and is not life-threatening.
Fun facts:
- Species of tarantula hawks have been seen as far north as Utah and as far south as Argentina, with more than 250 species living in South America.
- Fifteen species of Pepsis are found in the United States, most of them residing in the desert.
- They are generally active during the summer months. They avoid the hottest part of the day (mine was out in early evening).
- Due to their extremely large stingers, they have very few predators; only roadrunners and bullfrogs will take them on.
- The tarantula hawk is the state insect of New Mexico.
So, definitely admire this wasp from afar, but avoid contact, and make sure your kids and pets do as well!
by UC Master Gardener Rebecca Jepsen
This article first appeared in the August 26, 2018 print issue of the San Jose Mercury News.
