Primers for PCR were designed for three separate areas of the DNA encoding the rRNA. The first pair of primers, ITS1 (5′-TCC GTA GGT GAA CCT GCG G-3′) and ITS4 (5′-TCC TCC GCT TAT TGA TAT GC-3′), have been used in previous studies (15, 26). These give an expected PCR product extending from the 5′ end of the 18S rDNA to the 3′ end of the 25S rDNA and include both intergenic transcribed spacer (ITS) regions (ITS1 and ITS2) as well as the entire 5.8S rDNA.