Xenos vesparum, a twisted parasite

The story of a clever parasite in a wasp butt.


Picture yourself in Italy, in a Chianti vineyard.

[Cricket, cicada, and bird sounds fade in]

The sun is high in the summer sky, but it doesn’t shine on you, because you are a parasite hidden in the butt of a paper wasp.

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You are a twisted wing parasite, a small insect from order Strepsiptera. Safely hidden in the gaster of the wasp serving you as a home, you are almost ready to let your head peak between her tergites (the dorsal plates protecting her body). This will be the first step to reproduce, as you will be able to attract a male to mate with.

You are soon at the end of your life, as you will not survive the process of reproducing. The perfect time to reflect on your fascinating life, and your fusional relationship with your host. You entered it when it was only a grub, and you were an agile microscopic larva.

Like the thrifty parasite you are, once you were inside, you molted in a simpler form, without the legs you did not need anymore. You patiently waited for the grub to grow, slowly growing as well. And when the wasp grub started its final transformation, so did you.

As you were both adults, you started influencing its hormonal system, to be sure that instead of working together with other worker wasps, it would play another card of its behavioral hand, and think itself a queen waiting for the winter, and aggregate outside with other parasitized wasps. The perfect place for you to meet your male! You can even stay inside, as it is the male who will get out of his wasp-butt-home, and come find you.


Beani, L. (2006) ‘Crazy wasps: When parasites manipulate the Polistes phenotype’, Annales Zoologici Fennici, 43(5), pp. 564–574.