Age Dependency of Response in an Insect Chemoreceptor Sensillum

Abstract

THE electrical responses of contact chemoreceptors on the mouthparts of many species of Diptera can determine whether or not a fluid medium is ingested. In the blowfly Phormia terranovae, the responses of the large bristle-like sensilla, which occur in two aboral patches on the labellar lobes, regulate the extension of the proboscis and the opening of the labellar lobes. The responses of a single sensillum may mediate this action if stimulated with water or with certain sugars in aqueous solution¹. Without extension and opening, feeding is impossible. Rejection thresholds seem to be determined to some extent by the responses of the type 1 (“salt”) receptor cell, one of the four types of chemoreceptor cell contained within each sensillum².