For DNA purification, Crithidia mellificae (,10 6 trypanosomes/ mL culture medium) were pelleted by centrifugation (8006g for 6 min) and washed with PBS prior to DNA extraction. DNA was extracted using the DNeasy Genomic DNA Extraction Kit (Qiagen) as per the manufacturer's instructions. Bees from Crithidia positive hives were homogenized by TissueLyser as above and DNA extracted using the DNeasy kit for the initial PCR screens, after suspension in either PBS or 16 Micrococcal Nuclease Buffer (NEB).