New Mexico State Insect

Tarantula Hawk Wasp

(Pepsis formosa)

Adopted in 1989.

The selection of the insect was prompted by a group of Edgewood, New Mexico elementary school children doing research on states which had adopted state insects. They selected three insects as candidates, and mailed ballots to all schools for a state wide election. The winner was the Tarantula Hawk Wasp, Pepsis formosa. As part of the class project, the entire class attended the legislative hearing in Santa Fe when the bill was introduced. The insect was adopted by the 39th Legislature in 1989.

Several species of the wasps known as "tarantula hawks" that build nests in the ground and provide their young with spiders for food inhabit the desert lands of the southwest. Pepsis formosa and Pepsis thisbe are probably the two most common. Wasps in the genus Hemipepsis are also known as "tarantula hawks." The species are difficult to distinguish. The Pepsis formosa specie is the spicie selected by the state. The majority of these wasps have metallic blue bodies, reddish antennae, and fiery red wings except for the outer margins and base.

Only a few animals, such as roadrunners, eat tarantula hawks. The wasps are "nectivorous," and they have been known to become "flight-challenged" after consuming fermented fruit.

Tarantula hawk stings are considered to be the most painful of any North American insect. On a scale of one to four, Pepsis formosa was one of only two insects to rate a four. This compares with a one for a Solenopsis xyloni (desert fire ant), two for a Apis mellifera (honey bee) and three for a Dasymutilla klugii (velvet ant). Although painful, the Pepsis sting is not especially lethal. It rates a 38 on a lethal capacity scale. This compares with 5.9 for a Dasymutilla klugii, 54 for a Apis mellifera, and 200 for a Pogonomyrmex maricopa (a desert-dwelling seed-harvester ant).

Their means of reproduction is what gives them their name. Tarantula hawks are most active in the summer, during the day, although they avoid the highest temperatures. Females give the wasps their common name. Like all members of this genus, they require a spider to serve as host for their larvae, and in the case of the local species, tarantulas are the preferred nursery. This specie is unique in that, while only being approximately ¾ to 1½ inches in length, the females who are ready to lay eggs disturbs the web near a tarantulas burrow, and when the tarantula appears the wasp stings the spider and injects venom.

Instead of killing the tarantula, the venom only causes paralysis. The wasp then drags the tarantula to a burrow, stuffs it down the hole, and then lays her eggs on top of the paralyzed spider. Several days later the eggs hatch, and the larvae feed on the still living tarantula. When the larvae mature they metamorphose into adult wasps to complete the cycle.

Common Name: Tarantula Hawk, Tarantula Wasp, Tarantula Hawk Wasp
Latin Name: Hemipepsis spp.
Habitat: Dry hillsides and rolling arid plains
Range: California and Mexico