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.

Seasonal variation of oribatid mite (Acarina) populations and their relationship to sheep cestodiasis in Argentina.

Samples of soil were collected monthly from two ranches in the zone of Puan, Province of Buenos Aires, Argentina. The monthly distribution of males, females without eggs and females with eggs for the dominant species of oribatid mites were studied. The dominant species were Zygoribatula lata in Ranch A, and Zygoribatula elongata in Ranch B. Both species are hosts of Moniezia expansa Rudolphi, 1810 and Helictometra giardi Baer, 1927. Based on the data presented, the factors associated with transmission of these cestodes, including the role played by oribatid mites, are discussed.

Laboratory and field studies on oribatid mites as intermediate host of Moniezia expansa infecting Egytptian sheep.

Three species of oribatid mites, Scheloribates zaherii, Zygoribatula tadrosi and Z. sayedi from pure colonies were experimentally exposed to infection by allowing them to feed on stool sheep infected with Moniezia expansa. The mites were followed up to the development of the infective cysticercoids. M. expansa was able to achieve sucessfully its larval development in the three species of oribatid mites under laboratory conditions. These were demonstrated after 84, 73 & 69 days post infection, respectively. Z. tadrosi is recorded as inter-mediate host for the first time in Egypt. Six species of oribatid mites, Oppiella nova, S. laevigatus, S. zaherii, Xylobates souchiensis, Epilohmannia pallida aegyptiaca and Z. sayedi, recovered from the sheep infested farm soil, were found naturally infected with different developmental stages of M. expansa.