Tarantula hawk
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Pepsis |
The tarantula hawk is the common name for species in the genera Pepsis and Hemipepsis of the family Pompilidae, in the insect Order Hymenoptera. These genera of wasps are called tarantula hawks due to their hunting of tarantulas as food for their larvae.
Tarantula hawks are up to two inches (50mm) 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 potential predators that they are dangerous. 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.
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[edit] Hunting, Feeding
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. Tarantula hawks are "nectarivorous." The consumption of fermented fruit sometimes intoxicates them to the point that flight becomes difficult. While the wasps tend to be most active in daytime during summer months, they tend to avoid the very highest temperatures. The male tarantula hawk has an interesting behavior: many act in a behavior called "hill-topping", where they sit on top of tall plants and look out for females who are ready to reproduce.
[edit] Geographical distribution
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 Oregon, 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 deserts of the southwestern United States, with Pepsis formosa and Pepsis thisbe being common. The two species are difficult to distinguish, but the majority of Pepsis formosa have metallic blue bodies, reddish antennae, which separates them from Pepsis thisbe (both species have bright orange wings that become transparent near the tip).
[edit] Sting
These wasps are usually not aggressive[1], but the sting, particularly of Pepsis formosa, is among the most painful of any insect. Commenting on his own experience, one researcher described the pain as "...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."[2] 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 fatal less often than the honey bee. Their large stingers are considered defensive adaptations for living in the open, where they are prone to predators. Because of their stingers, very few animals are able to eat them; one of the few animals that can is the roadrunner.
[edit] Notable references
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, Pepsis formosa).
