Piroplasmal sporozoites in the Argasid Ornithodoros erraticus (Lucas)

The infective forms of Nuttallia meri, a small-mammal piroplasm, first appear as spindle-shaped sporozoites in and around the salivary glands of Ornithodoros erraticus (small race) 30 days after the ticks had fed on infected blood. O. erraticus is the only soft tick so far proved to transmit a piroplasm.