Hemipepsis ustulata is a species of tarantula hawk wasp native to the Southwestern United States.

Tarantula hawks are a large, conspicuous family of long-legged wasps that prey on tarantulas by using their long legs to grapple with their prey and then paralyze them with a powerful sting (ranked as one of the most painful in the insect world by the Schmidt sting pain index).

[3] H. ustulata is common in the arid climate of the Southwestern United States, ranging from California through Arizona, New Mexico, and Texas, and as far north as Nevada, Oklahoma, and Kansas.

The males, which are significantly smaller than the females, possess more slender bodies and exhibit a more vibrant hue in their wings, serving as a visual cue during mating rituals.

The wasp's antenna, with its unique curve and twelve segmented parts, provides an additional layer for identification, distinguishing it from other Pompilidae members.

It cuts a hole into the tarantula's carapace and thrusts its head and thorax inside the host spider, continuing to feed ravenously.

The grub is much smaller than it was at the end of feeding because it has expended so much body content on spinning the cocoon and voiding its alimentary canal.

[6] Upon reaching the pupal stage, the head capsule splits along the mid-line, and a glassy, whitish pupa forces its way out of the discarded larval skin.

The pupa turns creamy yellow, with gray-blue, large compound eyes showing through the thin integument.

A sharp scratching noise can be heard as the young wasp cuts its way out of the tough cocoon with its strong mandibles.

However, the wasps' powerful residual odors, flight patterns, and flashy colors are all likely candidates for how they communicate with each other.

In a lekking species, the male-defended territory does not contain incentive of resources for females, such as food, shelter, or attractive nesting sites.

John Alcock's studies emphasize the importance of size variation in claiming desirable territories among male H. ustulata wasps.

The size of the tarantula captured by the mother wasp determines how big the larva will become when fully grown.

The territorial males of this species perch on prominent vegetation at high elevations (1500 m or higher) and chase away intruders.

On occasion, the intruder engages in aerial combat with the territory owner over possession of the perch, a tree, or bush.

Adult wasps spend lengthy periods of time patrolling and actively searching for prey on the ground.

Popular sources of nectar include milkweeds (Asclepias) and western soapberry trees (Sapindus saponaria).

Instances of predation by roadrunners in the literature are rare at best, even on harmless males, which speaks to the defensive effectiveness and reputation of tarantula hawks in the animal kingdom.

Evidence suggests the convergent evolution in perching and patrolling site preferences of H. ustulata with other hill-topping insects of the Sonoran Desert.

[4] The high mountain ridges attract the males of various hill-topping insect species, including tarantula hawk wasps, various butterflies, and botflies.

[4] This similar ranking preference for territories suggests a widespread convergence among the capacity of hill-topping insects' compound eyes in their perception of what constitutes a conspicuous landmark feature.

is described on the Schmidt sting pain index as "blinding, fierce, shockingly electric" and "like a running hair dryer has just been dropped in your bubble bath".

In humans, the pain of the sting can be lethal depending on the person's condition including weight and body mass.