Infectivity of Moniezia benedeni and Moniezia expansa to oribatid mites from Ohio and Georgia.

Six species of oribatid mites belonging to four families and five genera were successfully infected by M. benedeni. They were Scheloribates laevigatus (Scheloribatidae), Exoribatula sp. cf. biundatus (Scheloribatidae), Xylobates capucinus (Haplozetidae) and Zygoribatula undulata (Oribatulidae) from Ohio, and Galumna ithacensis (Galumnidae) and Scheloribates lanceoliger (Scheloribatidae) from Georgia. Cysticercoids were also recovered from S. laevigatus infected with M. expansa. Among the six species of mites, S. laevigatus is the major intermediate host of M. expansa and M. benedeni worldwide, while the other five species have not been previously reported as transmitters of Moniezia spp. This is also the first report of any species from the genera Exoribatula and Xylobates as intermediate hosts of tapeworms. Different species of oribatid mites varied in their efficiency as intermediate hosts of M. benedeni. Moniezia benedeni had higher infection rate and infection intensity in S. laevigatus than in other species. Development in S. laevigatus was also more rapid than in the other species. Mite size was only one of the determinants of intermediate host efficiency. Storage at 4 degrees C for 1 to 5 weeks reduced the viability of M. benedeni eggs. Stored eggs had lower infection rates and infection intensity and slower development in S. laevigatus. They also had lower infection rates in X. capucinus and Exoribatula sp. cf. biundatus.