PHEROMONAL COMPOSITION OF 2 SPECIES OF AFRICAN AMBLYOMMA TICKS - SIMILARITIES, DIFFERENCES AND POSSIBLE SPECIES-SPECIFIC COMPONENTS

Two species of bont ticks, Amblyomma hebraeum and Amblyomma variegatum , common to Africa were studied to compare types and quantities of com pounds known or believed to serve as components of the attraction-aggr egation-attachment pheromone (AAAP). A complex of attraction, aggregat ion and attachment stimulating pheromone components are used by these ticks to detect hosts, mates and, perhaps, minimize interspecific bree ding. Solvent extraction of pheromone emitting ticks followed by gas c hromatography and mass spectrometry revealed little qualitative differ ence in the composition of the AAAP in these two species. However, sub tle differences in the relative proportions of the pheromonal blend ar e noted suggesting that such differences in concentration may facilita te species-specific discrimination during aggregation and attachment. Differences in the relative abundance of benzaldehyde and methyl salic ylate in the males of the two species were especially noteworthy. Poss ible means by which such differences in phenolic compound composition may affect the behavior of these ticks are discussed.