Distribution and specific central projections of mechanoreceptors in the thorax and proximal leg joints of locusts.

Campaniform sensilla (CS) of the locust proximal leg segments are arranged predominantly as homologous groups on the trochantera and femora. Their number is reduced in the more specialized jumping legs. The specific projections of the primary afferent axons from single groups of CS are visualized after backfilling them with CoCl2 introduced through the dendritic area in the cuticle. The majority of central branching patterns reveal a high degree of uniformity if compared within a population, between populations of one segment, and between populations of different legs. All projections bifurcate close to the peripheral root of the leg nerve and are restricted to the ipsilateral hemiganglion of the segments. These projections seem to differ in their extent more or less from those campaniform sensilla in other parts of the locust and in other insects.