Sound production in bark and ambrosia beetles
Bark and ambrosia beetles and pinhole borers (Coleoptera: Curculionidae: Scolytinae and Platypodinae) are two subfamilies of weevils that use acoustic communication within plant tissue. Theseinsectstransmitanddetectsoundinamediumthatisneither air nor water and they are among the smallest animals with soundproducing organs. Nevertheless, their sound production is sorely understudied, mostly due to the diﬃculties associated with acoustically monitoring individuals inside plants. We analysed the stridulatory sounds from 55 bark and ambrosia beetle species within 15 subtribes collected in four countries, making this the largest acoustic dataset of these taxa to date. We characterised and compared the amplitude and spectro-temporal parameters of the distress airborne signals produced by the beetles, in conjunction with phenology and life history data. Sound production was present in 33% of the collected species, of which 60% of these sounds had not been previously reported. Depending on species, either both sexes stridulated or only one. Some species had calls with diﬀerent acoustic morphotypes (one, two, or three notes), and when both sexes stridulated, sounds generally diﬀered. Our data suggest that type of mating system and size play an important role in determining the acoustic communicatory capacity of most species.