Electrophysiological Responses of the Terminal Sensilla on the Maxillary Palps Of Locusta Migratoria (L.) To Some Electrolytes and Non-Electrolytes

ABSTRACT Three morphologically and functionally different types of sensilla on the maxillary palp tips of Locusta migratoria are distinguished and an electrophysiological study is made of the most commonly occurring type. Responses to stimulation with 0·1 M sodium chloride show impulses of one, two or three amplitude categories in different sensilla. Variability of response to a constant stimulus is appreciable, both between and within sensilla. Tests with a range of compounds indicate that individual neurones are capable of responses to compounds of different chemical classes. Specificity of sensilla is more marked than specificity of neurones. Methods of interpretation of results are evaluated and the results are discussed in the context of discrimination of food plant materials.