KINETICS OF MALE PHEROMONE PRODUCTION BY AMBLYOMMA-VARIEGATUM (ACARI,IXODIDAE)

Males of Amblyomma variegatum (F.), when attached on their host, produ ce a pheromonal blend composed of methyl salicylate, ortho-nitrophenol , and nonanoic acid, which acts as an aggregation-attachment pheromone . Using olfactometry assays, assays on hosts, and quantification of th e compounds by capillary pas chromatography, the kinetics of pheromone production has been studied. Males engorged for at least 10 d elicit attachment from most of the tested females. attractiveness of males fo r females is significant only between days 14 and 23 of engorgement. B efore 10 d of attachment, the amounts of pheromones detected in hexani c male body extracts are very low (<10 ng); they then increase to a ma ximum of 2 mu g for the major compound per male. Large amounts can be detected until 80 d of engorgement. The inter-individual variation is very large throughout the engorgement period. The interest and the lim itations of the different techniques used are discussed.