Abstract
Many dipteran and hymenopteran insects use near-field sound caused by wing beat for conspecific communications. One of the most sophisticated sound communications is seen in the waggle dance of honeybee workers. Behavioral studies have collectively suggested that Johnston’s organ (JO) in the second segment of the antennae is a primary sensor to detect air-particle movements caused by the waggle dance. As a first step to elucidate central processing of the dance language, we recently investigated sensory subgroups in JO and their central projections in the honeybee. The comparison of the projection patterns in the honeybee with those in the fruitfly, mosquitoe revealed that axons of the sensory neurons in these species project extensively to the antennal mechanosenory center in the deutocerebrum, the posterior region of the protocerebrum (visuo-motor center) and the subesophageal ganglion, but some species-specific features were evident. The projections of the JO neurons in the cockroach were devoid of axon terminals in the protocerebrum, indicating that the projection to the visuo-motor center is an innovation in flying, holometabolous insects. The possible roles of extensive termination fields of JO afferents in parallel processings of mechanosensory signals are discussed.
