DOSE-DEPENDENT RESPONSE CHARACTERISTICS OF ANTENNAL LOBE NEURONS IN THE MALE MOTH AGROTIS-SEGETUM (LEPIDOPTERA, NOCTUIDAE)

Responses of antennal lobe neurons to different amounts of the female- produced pheromone blend and to its individual components were investi gated in Agrotis segetum males using intracellular recording methods. We identified three physiological types of antennal lobe neurons, cate gorized according to their response thresholds to single pheromone com ponents and to the blend: generalist neurons, component-specific neuro ns and blend-specific neurons. Response and specificity of antennal lo be neurons were largely dose dependent. In most cases specific respons es occurred only at low stimulus amounts, while increasing concentrati ons often resulted in an increase of the number of pheromone stimuli t o which the neuron responded. Dose-response relationships often differ ed between different stimuli activating a neuron.