As nouns,
vespertilian bat is a hypernym of
Pipistrellus pipistrellus; that is, vespertilian bat is a
word with a broader meaning than Pipistrellus pipistrellus:
Pipistrellus pipistrellus: small European brown bat
vespertilian bat: a variety of carnivorous bat
Other hypernyms of Pipistrellus pipistrellus include
vespertilionid.