The cave organ is a sensory receptor in the antenna pedicel of some
Reduviidae
. This paper describes this organ for the first time in three species of the genus
Belminus
,
Belminus corredori
,
Belminus ferroae
and
Belminus herreri
, by optical and scanning electron microscopy. The structures presented a general pattern similar to one reported for other species of Triatominae.