IDENTIFICATION OF VERTEBRATE VOLATILES STIMULATING OLFACTORY RECEPTORS ON TARSUS-I OF THE TICK AMBLYOMMA-VARIEGATUM FABRICIUS (IXODIDAE) .1. RECEPTORS WITHIN THE HALLERS ORGAN CAPSULE

Gas chromatography-coupled electrophysiological recordings (GC-EL) fro m olfactory sensilla within the capsule of Haller's organ of the tick Amblyomma variegatum indicate the presence of a number of stimulants i n rabbit and bovine odours, and in steer skin wash. Some of these stim ulants were fully identified by gas chromatography-mass spectrometry a nalysis and by matching electrophysiological activity of synthetic ana logues as: 1) hexanal, 2-heptenal, nonanal, furfural, benzaldehyde, an d 2-hydroxybenzaldehyde (in all extracts); 2) heptanal, 2-, 3-, and 4- methylbenzaldehyde, and gamma-valerolactone (only in bovine and rabbit odour). Careful examination of the electrophysiological responses per mit characterization of 6 receptor types: 1) a benzaldehyde receptor, 2) a 2-hydroxybenzaldehyde receptor, 3) three types of receptors respo nding differently to aliphatic aldehydes, and 4) a lactone receptor.