STUDIES ON THE ANOPLOCEPHALATE CESTODES AND THE ORIBATID MITE VECTORS OF MONIEZIA IN AR-BAR COUNTY, SICHUAN PROVINCE

In the autumn of 1980, eight species of anoplocephalate cestodes, namely Moniezia ex-pansa, M. benedeni, Avitellina centripunctata, Anoplocephala perfoliata, A. magna, Parano-plocephda mamillana, P. ryjikovi and P. transversaria were collected and identified from the stocks and marmots in Ar-Bar County, Sichuan Province.1,905 domestic animals were examined by fecal examination, and 243 of them (12.76 %) were found infected with anoplocephalids. Among 1,081 sheep 171 positives harboured Moniezia, 63 of 727 yaks were also infected with Moniezia, while 9 of 97 horses showed the infection of Anoplocephala and Paranoplocephda. As to age incidence, we found that 29.63% of infected sheep belonged to the one-year group, 20.84% to the two-year group and 14.49% to the three-year group respectively. At the same time, post-mortem examinations were made on 88 sheep slaughtered, and 25 of them (28.41%) were found infected with Moniezia and Avitellina. Biopsies were also made on 21 marmots, Marmota himdayana, 3 of them (14.29%) were found to harbour Paranoplocephala ryjikovi and 7 of them (33.33%) infected with P. transversaria.27,000 oribatid mites, belonging to four genera and eight species, were collected and dissected from the turp sampes of pastures in Hong-Yuan region. 14 of them (0.051%), involving three species, were found to be naturally infected with the cysticercoids of Moniezia. The number of cysticercoids per mite varied from 1 to 3. The incidence rates for these three species of mite vectors were: (1) Scheloribates chauhani 0.070%, (2) S. sp.1 (small form) 0.077% and (3) Parakalumma lydia 0.050%. 4,760 mites collected from the summer pasture were examined, and 6 of them (0.126%) appeared with the cysticercoids of Mon-iezia. 23,000 mites from the winter pasture showed only 8 positives harbouring cysticercoids of Moniezia. This observation indicates that the majority of the infected animals would become infected by swallowing the mite vectors on the summer pastures during the warmth of summer months. The specific characters and distributional patterns of the mite vectors are briefly described and discussed in this paper.