Tympanic arenas for assays on termite vibroacoustic signalling
Og Francisco Fonseca de Souza, Livia Fonseca Nunes , José Augusto Roxinol , Paulo Fellipe Cristaldo , Renan Luis Marinho , Og Francisco Fonseca de Souza
Departamento de Entomologia, Universidade Federal de Viçosa, Brazil; Departamento de Entomologia, Universidade Federal de Viçosa, Brazil ; Departamento de Entomologia, Universidade Federal de Viçosa, Brazil ; Departamento de Agronomia, Universidade Federal Rural do Pernambuco, Brazil ; Departamento de Entomologia, Universidade Federal de Viçosa, Brazil ; Departamento de Entomologia, Universidade Federal de Viçosa, Brazil
In termites, substrate-borne vibrations play an important role in communication among nestmates. The adaptive significance of such an ability has led to an ever increasing number of studies aimed at improving knowledge on vibroacoustic communication in these insects. Such studies are commonly carried out in laboratory arenas consisting of Petri dishes made of plastic or glass. However, the rigidness of such materials may limit the transmission of vibrational waves impairing accurate records of the feeble vibrations produced by termites. This is one the reasons why such experiments must be carried out under strictly controlled conditions, using extremely sensitive equipment, usually connected to amplifiers. If, instead, arenas bear a flexible floor (hence simulating a tympanum), vibrations might be not dampened or even easily amplified, thereby overcoming the need for such a specialized setup. Here we test such a hypothesis, using an accelerometer to measure and record vibrations whose intensity was tailored to mimic the feeble vibrations of a small termite species, Constrictormes cyphergaster (Termitidae: Nasutitermitinae). Results support the notion that tympanic arenas portray such vibrations far more accurately than arenas made of plastic or glass. We hence recommend this type of arena as a cheap, albeit accurate, alternative in studies of vibroacoustic behaviors of termites and other insects of comparable size especially in situations where noise is minimally controlled. These arenas, then, can be useful in conducting such studies just after termite collection in remote regions where well-equipped labs are not available. In doing so, we minimize the stress involved in transporting termites over long distances.