cysticercoid of Hymenolepis diminuta.  The suffix indicates it is like a cysticercus but this larva has no bladder but instead has a tail.  The dark body within the spherical portion is the scolex.  The longer the tail, the more mature the cysticercoid. This stage is found inside an insect such as the mealworm, Tenebrio molitor.   100x