Tarantula hawk

Tarantula hawk
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Suborder:	Apocrita
Superfamily:	Vespoidea
Family:	Pompilidae
Subfamily:	Pepsinae
Tribe:	Pepsini
Genera
Pepsis Hemipepsis

The tarantula hawk is the common name for certain wasps belonging to the family Pompilidae, in the insect Order Hymenoptera. The Pompilidae are commonly referred to as spider wasps, with many species in the genera Pepsis and Hemipepsis being called tarantula hawks due to their hunting of tarantulas as food for their larva.

A tarantual hawk digging a hole in the parking lot at Scotty's Castle, Death Valley National Park. Picture by Matti Mero, 2003.

Tarantula hawks are up to two inches (40mm) long with a blue-black body and bright rust-colored wings. The bright rust coloring that they have on their wings, is also known as aposematic coloring, this warns its predators that they are dangerous to eat.Their long legs end with hooked claws for grappling with their victims. The stinger of a female tarantula hawk can be up to 1/3 inch (7 mm) long.

Female tarantula hawks may hunt for wandering male tarantulas. However, during the insect's reproductive season male tarantulas are usually emaciated from ignoring food while searching for females. The tarantula hawks prefer female tarantulas and seek them in their burrows. They capture (often following a dramatic battle), sting and paralyze the spider. Next they either drag the spider back into her own burrow or transport their prey to a specially prepared nest where a single egg is laid on the spider’s body, and the entrance is covered. The wasp larva, upon hatching, begins to suck the juices from the still-living spider. After the larva grows a bit the spider dies and the larva plunges into the spider's body and feeds voraciously, avoiding vital organs for as long as possible to keep it fresh. The adult wasp emerges from the nest to continue the life cycle. Very few animals are natural enemies to these wasps; the roadrunner being one example. The wasps are "nectivorous," and they have been known to become "flight-challenged" after consuming fermented fruit. Tarantula hawks are most active in the summer, during the day, although they avoid the highest temperatures. The male tarantula hawk, also has a very important role: many act in a behavior called "hill-topping", where they sit on top of higher plants and look out for virgin females who are ready to reproduce.

Worldwide distribution of tarantulas includes areas from India to Southeast Asia, Africa, Australia, and the Americas, where these predatory wasps are also likely to be found. Tarantula hawk species have been observed from as far north as Utah, in the United States, and south as far as Argentina in South America, with at least 250 species living in South America. Several species of tarantula hawk are found in the desert of the southwestern United States, with Pepsis formosa and Pepsis thisbe being common. The two species are difficult to distinguish, but the majority Pepsis formosa have metallic blue bodies, reddish antennae, and fiery red wings except for the outer margins and base, which allows them to be identified over the Pepsis thisbe.

The sting, particularly of Pepsis formosa, is among the most painful of any insect. Commenting on his own experience, one researcher said, "You will curse your mother for ever having you." Another described, "...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." Yet another said, "It's not like things that make you swear and say bad things about somebody's mother. These things, when you get stung, you might as well lie down and scream. Why not? It takes your attention off the pain." It is listed near the top of the list in Schmidt Sting Pain Index. Although the sting is quite painful the effect is reported to last only a few minutes and is less lethal than that of the honey bee. Because of their stingers, very few animals are able to eat them, one of the few animals that can eat them is the roadrunner. Hawk Wasps are said to have such large stingers because they have adapted to living in the open, where they are prone to predators.

The U.S. State of New Mexico chose the insect in 1989 to become its official state insect. 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 (specifically, the Pepsis formosa species).

External links

• DesertUSA page on tarantula hawks