Distribution and function of the antennal olfactory sensilla in ceratitis capitata wied. (diptera, trypetidae)

Abstract

Morphological observations by means of scanning electron microscopy and electrophysiological tests consisting of electroanten- nogram recordings (EAGs) were performed on the third antennal segment (flagellum) of female and male Ceratitis capitata Wied. The number and the distribution of the four types of chemosensilla present on the flagellar surface (basiconic, clavate, trichoid, and grooved) were not related to sex, and sex did not influence the responsiveness of the flagellar chemosensilla to some volatiles usually occurring in the habitat of Ceratitis. Ethanol, butanol, amyl alcohol, 1-hexanol, and hexanal proved to be the most effective stimulants, while 1-nonanol, 1-decanol, octyl aldehyde, and nonyl aldehyde did not exert relevant stimulating effects. Concerning the specific responsiveness of the chemosensillar types, basiconic and clavate sensilla were of major importance in EAG responses to short chain aliphatic alcohols such as ethanol, butanol, and amyl alcohol. © 1989 Taylor & Francis Group, LLC.