Tarantula Hawk Wasp
Images are from Integrated Landscape Management's Business Support Specialist, Dan Munson.
Tarantula Hawk Wasp
Pepsis formosa & Pepsis thisbe
The Tarantula Hawk Wasp (also just Tarantula Hawk) is a large (2-3 inches long), predatory wasp that are easily identified by their bright orange wings and blue-black body. Pepsis formosa is recognized by a more metallic body color and reddish antennae, but are otherwise indistinguishable from Pepsis thisbe. Both species of Tarantula Hawk Wasps are common in the Southwestern USA & Northern Mexico.
These wasps are also nectarivorous, meaning they consume nectar, especially that of Milkweeds (i.e. Desert Milkweed [Asclepias subulata]), Western Soapberry trees (Sapindus saponaria ssp.), & Mesquite trees (i.e. Velvet Mesquite [Prosopis velutina]). As their name implies, they predate tarantulas for their offspring. Tarantula Hawks paralyze their prey and carefully lay an egg inside the body of the tarantula, so as to keep it alive. The larva voraciously feeds on the tarantula after hatching.
Tarantula Hawk Wasps are generally docile, but will attack if provoked. The sting of this wasp is considered the most painful sting in North America, and the second most painful in the world (according to the Schmidt Sting Pain Index) below the Bullet Ant (Paraponera spp.) of Central & South America. The sting of the Tarantula Hawk Wasp has been described by DesertUSA.com, saying, “…an immediate, excruciating pain that simply shuts down one’s ability to do anything, except, perhaps, scream. Mental discipline simply does not work in these situations.”
The sting is considered unusually powerful for a solitary insect, as societal insects, such as honeybees, are known to have more painful stings for which to defend the nest. DesertUSA.com also says, that although the sting is painful, “…the Pepsis sting is not especially lethal.” The LD50 (or Median Lethal Dosage) of Pepsis sp. is approximately 65mg per 1kg, according to Universidad Nacional de Colombia. In comparison, Honeybees (Apis mellifera) rate at 2.8mg/kg for lethality and Maricopa Harvester Ants (Pogonomyrmex maricopa), known for having the most toxic of insect venom, rate at 0.125mg/kg.
Tarantula Hawk Wasps build their nests in the soil, and tend to do so in the more wild parts of the Southwest where tarantulas are generally found. So homes and businesses located on the outskirts of the Phoenix metropolitan area and those out in the more remote areas of Arizona are in potential risk of having these wasps visit. Should one be seen, it’s recommended to just leave it alone, and if need be, leave the area. If a nest is identified, EnviroControl may be able to help. Do not approach or attempt to destroy the wasps nest, as this may not stop or kill the wasps, but rather excite and anger them.
Other Relative Terms
Predatory Wasps, Dangerous