Figure 1

Outline of the developmental schemes for audition in six orders of insects. In the two taxa Coleoptera and Diptera of holometabolous insects the scolopidial sense organ for hearing develops during the pupal stage (generation of cells: yellow; differentiation: dotted line). Shortly after emergence the adult hearing capability is aquired (red). In at least some Lepidoptera the scolopidia develop during embryogenesis and are remodeled during the pupal stage (broken line) for the innervation of the adult tympanal organ. The larval function is probably proprioception (blue). In the Hemimetabola the scolopidia are formed during embryogenesis. In the Saltatoria and the Mantodea, the hearing capabilities develop gradually with the postembryonic larval stages (blue-red line). In the Auchenorrhyncha the cells probably develop during embryogensis and two separate functions are proposed for the larva and the adult (see text).