trichobothrium
From ZooTerms (Dictionary of Invertebrate Zoology)
Arthropoda: Chelicerata) A compound structure of many groups consisting of a small cavity (bothridium) and variously shaped setae (bothridial setae) that function as vibro- and anemoreceptors.
trichobothrium (noun; plural -ria; Greek thrix, hair; bothros, pit): (