ULTRASTRUCTURE OF THE APOROUS SENSILLA ON THE GALEA OF LARVAL MAMESTRA-CONFIGURATA (WALKER) (LEPIDOPTERA, NOCTUIDAE)

The galea of fifth-instar Bertha armyworms, Mamestra configurata, has three types of aporous sensilla: one spire-shaped basiconic peg, two s hort basiconic pegs, and one campaniform sensillum. The spire-shaped p eg is set in an inflexible socket, innervated by three bipolar neurons , and enveloped by three sheath cells. One microtubule-laden dendrite completely fills the distal portion of the dendritic sheath and ends w ithin the peg. It is joined by a lamellate and a scolopidium-like dend rite that end near and below the base of the peg, respectively. The ci liary sinus is large and the membrane of the enveloping inner sheath c ell is highly elaborate. This sensillum exhibits features characterist ic of thermo-hygrosensilla. The short basiconic pegs and campaniform s ensillum are each innervated by a single bipolar neuron and each is as sociated with three sheath cells. In both sensilla, the dendrite ends in a tubular body, typical of mechanosensilla.