A fear of spiders is common when it comes to humans. But it sounds uncanny if someone says that a spider, such as the large tarantula, is scared of a small wasp. It’s uncanny but true. There exists a wasp, the tarantula hawk, that can make a tarantula run away in fear. The sting of a tarantula hawk is so powerful that it paralyzes the tarantula spider permanently.  Also, their sting is considered to be one of the most painful stings in the world.

The tarantula hawk is a species of spider wasps that is famous for hunting down tarantulas. They are parasitoid wasps, and they use their sting to paralyze their prey which they feed upon later.

Tarantulas are one of the creatures that give people the creeps. Their venom is not fatal to humans but can cause excruciating pain. Because of their large size, they are powerful enough to attack, kill, and eat a variety of other prey. But there exists a wasp that preys on these large spiders. Known commonly as the “tarantula hawk,” they are parasitoid wasps that paralyze and prey on tarantulas for food. “Parasitoid” means that their larvae survive as parasites, eventually killing the hosts.

The tarantula hawk belongs to a number of species under the genus Pepsis and Hemipepsis.  Wasps belonging to the most common species grow up to 5 cm in length. This makes them one of the largest wasps in existence. The largest species of tarantula hawk, Pepsis heros, grows to the length of 11 cm.

They are easily recognizable with their blue-black bodies and bright rusty wings. Some of them have black wings with blue highlights on them. Scientists believe that the wasps’ brightly colored bodies are an aposematism. “Aposematism” refers to the use of signals by animals, primarily visual signals like bright marking on bodies, to warn predators that they are either toxic or distasteful. So, the tarantula wasp uses its brightly colored wings to let predators know that they shouldn’t prey upon the wasps since they are toxic.

Only the female tarantula hawk battles the spiders to provide food for their offspring. They pierce the tarantula with a sharp sting and rapidly inject their venom. This permanently paralyzes the spider, keeping it alive. Depending on the size of the spider, or the food for the offspring, the female decides the sex of the baby. 

When it comes to battling off a tarantula, it is the female tarantula hawk that engages in an encounter. Her sting first paralyzes the spider. After the paralysis kicks in, the female drags the heavy spider to a special nest that she had prepared. Once the paralyzed spider is secured, the female then lays her egg, only a single egg, on the abdomen of the spider. The entrance to the nest is then sealed.

The tarantula hawk possesses an ability to decide the sex of their babies. In case the eggs are fertilized, they would grow into females. Unfertilized eggs lead to males. This ability has a major significance. As we already know,  it is the females who need to be strong in the tarantula hawk family to fight off spiders and secure food for the newborns. While deciding the sex for the baby, the law of supply and demand kicks in. More food means a stronger tarantula hawk. So if the female is able to secure a large-sized tarantula, she knows that her offspring will get enough food and grow strong. In that case, she chooses her baby to be a female. If the tarantula is small, she chooses a male.

Once the egg hatches, the larva creates a small hole in the spider’s abdomen. It then enters through it and feeds off the spider to survive. The vital organs are eaten last so that the spider remains alive for a longer time. The larva pupates after several weeks and becomes an adult. It then emerges from the spider’s abdomen to lead a normal lifecycle.

The male tarantula hawks simply feed off the nectar from fruits and flowers. This diet makes them so intoxicated that it affects their flight.

The pain inflicted by a tarantula hawk’s sting has been rated as one of the worst in the insect world. If a human is stung, the only recommended response is to “lay down and scream.”

Dr. Justin Schmidt, an entomologist and an expert on the study of insects, has invented a pain index upon being stung by an insect. He named it the “Schmidt sting pain index.” Apparently, the index has been named after some other man named Schmidt, not Justin Schmidt himself. The index ranks the pain of stings from insects from one to four. An example of an insect at one is the fire ant, while up at four is the bullet ant. The bullet ant has been named so because its sting feels like you have been shot!

The tarantula hawk joins the bullet ant at four. This should give an idea as to how terrible the pain from a tarantula hawk’s sting can be. It only lasts for about three minutes, but the pain is just unacceptable. Ben Hutchins, invertebrate biologist of Texas Parks and Wildlife says, “There are some vivid descriptions of people getting stung by these things and their recommendation — and this was actually in a peer-reviewed journal — was to ‘just lie down and start screaming,’ because few if any people could maintain verbal and physical coordination after getting stung by one of these things. You’re likely to just run off and hurt yourself. So just lie down and start yelling.”

Tarantula hawks are distributed worldwide across areas from India to Southeast Asia, Africa, Australia, and the Americas. Moreover, one species of the tarantula hawk was made the official state insect of New Mexico.

Tarantulas are found in regions across India to Southeast Asia. They are also found in Africa, Australia, and the Americas. In the United States, the tarantula hawk has been observed as far north as Logan in Utah. There are 18 species of Pepsis and three species of Hemipepsis in the United States. They are primarily found in the deserts of the southwestern United States. Pepsis grossa (formerly Pepsis formosa) and Pepsis thisbe are the most common ones to be found in the desert. In South America, some species of tarantula hawks are found as far as Argentina. There are around 250 species of tarantula hawks in South America.

The two species, Pepsis grossa and Pepsis thisbe, are very difficult to distinguish. One thing to look out for is that the Pepsis grossa has a metallic blue body and rusty reddish antennae. This helps distinguish them from Pepsis thisbe. 

New Mexico in the United States, chose the Pepsis grossa in 1989 to become its official state insect. The idea to nominate a state insect came from a group of elementary school students who were doing research on states that have adopted state insects. They shortlisted three insects as potential candidates and sent out ballots to all the schools in the state for their vote. One clear winner emerged, and it was the tarantula hawk.
[source: 1,2,3,4]