Identification of xanthine and hypoxanthine as components of assembly pheromone in excreta of argasid ticks.

In addition to guanine, xanthine and hypoxanthine were identified in white spherules in excreta of five species of Argas and Ornithodoros ticks by a reverse-phase high-performance liquid chromatography (HPLC) and a gas chromatographic method with mass spectrometric detection (GC/MS). The mutual relationships of these purines in excreta of Argas (Persicargas) persicus were found to be less than 1.5% for hypoxanthine, less than 9.0% for xanthine and 89.8-98.6% for guanine. In excreta of other species, the relationships of purines were similar, with the exception of Argas (A.) reflexus and A. (A.) polonicus, where the amount of hypoxanthine was rather elevated. Uric acid was also identified in some cases. The assembly efficacy of xanthine and hypoxanthine is similar to that of guanine, but xanthine significantly enhances the assembly efficacy of commercial guanine when mixed in ratio of about 1:25. Thus, xanthine seems to be the second important component of assembly pheromone of argasid ticks.