Pilifer is the hearing organ present in

Pilifer is the hearing organ present in Hawk moths.
A pilifer or labral pilifer is part of a hearing organ found on the heads of hawkmoths of the subtribe Choerocampina. This organ detects the high-pitched echolocation sounds of insectivorous bats and enables the moth to elude them.
The labral pilifers and the labial palps form ultrasound-sensitive hearing organs in species of two distantly related hawkmoth subtribes, the Choerocampina and the Acherontiina.