#54: Tarantula Hawk

Litinsects #54: Tarantula Hawk

Get ready for a fascinating yet possibly terrifying post... You are looking at a tarantula hawk, a wasp that hunts (you guessed it) tarantulas. There are a number of wasp species that hunt various kinds of spiders or other insects. These wasps engage in a PARASITOID lifestyle.

Parasitoids are a type of parasite but there are subtle differences between the two terms. While both benefit at the expense of a host animal, parasites live on or inside a host for an extended period of time and, since they have it pretty good, they want to keep their host alive while they continue exploiting it. Parasitoids on the other hand always kill their hosts eventually and it is often (in insects, at least) only the larvae that parasitize while the adults are free-living.

So what’s this wasp’s deal? Here’s where it gets slightly disturbing... once adult female wasps are ready to lay eggs they go on the hunt for tarantulas. The wasp stings her victim, paralyzing it, and then drags the still-living spider back to her nest. The wasp lays a single egg on the spider’s abdomen and then seals the nest entrance. After hatching, the larva tunnels into the spider’s body and begins devouring its insides. It leaves the most vital organs until the end in order to keep the spider alive as long as possible. After a few weeks, the larva pupates and then emerges as an adult. And the spider... well, it dies.

Tarantula hawks are solitary. At around 5 cm (2 in) they are some of the largest parasitoid wasps
Adult wasps, both males and females, feed on nectar, not spiders. Males do not hunt spiders (because they don’t lay eggs) and are therefore the smaller sex
A female wasp can control the sex of her offspring (fertilized eggs are female and unfertilized eggs are male)! Because females will grow larger, a mother can decide which sex offspring to produce depending on the size of the spider she has caught
Theirs is one of the most painful insect stings in the world. A female’s stinger can be up to 7 mm long! However, they rarely sting humans unless provoked
Tarantulas don’t have any defense against the wasps other than running away. Although the battles seem very intense, wasps almost never get injured and most are successful in their hunt

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