Monday, July 4, 2022

Answer to Case 688

 Answer to the Parasite Case of the Week 688: Nit (egg) of Pediculus humanus capitis. 

As noted by Kosta Mumcuoglu, "it is the egg of the head louse, Pediculus humanus capitis with the embryo inside (legs visible) and the operculum still on the egg. We can also see the part of the glue which was used to attach the egg on the hair. The aeropyles are in a row while in case of the pubic louse eggs they are in a triangular order. See https://www.veterinaryparasitology.com/pthirus-pubis.html but also Case 293 in Creepy Dreadful Wonderful Parasites. It is by the way Pthirus not Phthirus pubis." 

Kosta is correct on all counts. Here are some of the key identifying features. I find the detail of the embryo within the eggs to be particularly striking. 

The eggs of P. h. capitis are typically glued onto the sheath of a hair, compared to the eggs of P. h. humanus, which are glued onto clothing (and don't have a nit sheath).  


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