Cryopreservation of aster yellows agent in whole leafhoppers.

Aster yellows agent was preserved in an infectious state in leafhoppers (Macrosteles fascifrons) that had been fed on infected asters and then frozen and stored as whole insects at -64 degrees C for up to 2 years. No difference in infectivity was observed between extracts prepared from insects stored at -28 and -64 degrees C for up to 21 weeks. Three solutions (glycine + magnesium chloride, glycine + magnesium chloride + sodium sulphate, and phosphate-buffered saline) were found to be equally suitable in preparing extracts from frozen leafhoppers.