388 Acarology 



earthworms. These two factors alone, the second possibly of really 

 great importance, are enough to warrant more extensive study of the 

 bionomics of this large, soil-inhabiting group. Jacot, in the United 

 States, had made a start toward this goal before he died but had ac- 

 complished little; Tragardh, in Sweden, in his study of forest soils has 

 contributed some knowledge; and Marie Hammer and S. L. Tuxen 

 are at present doing extensive work on the soil fauna, especially on 

 the oribatid mites, in Denmark. As can be seen, much remains to be 

 done. It is in the study of the soil fauna that the sampling funnels — 

 Berlese, TuUgren, and others, and their modifications — have come 

 into use, and through these one can gain an insight into the tremendous 

 amount of material which can be found in the soil. 



Kates and Runkel 1948 have reviewed the literature on the oriba- 

 tids as vectors of the sheep tapeworm, Moniezia expansa, and also 

 report on the other species of tapeworm which are known to utilize 

 the oribatid mites as intermediate hosts. Apparently there are no taxo- 

 nomic units of mites that are vectors; rather it appears that the deter- 

 mining factor is which species is dominant in the sheep pasture and 

 which is able to swallow the eggs of the tapeworm. Many mites are 

 present in pastures but are too small to be vectors; other mites capable 

 of being the intermediate host under laboratory conditions will be 

 found to be forest-humus-inhabiting mites, not pasture forms, and 

 therefore of no importance in transmitting the tapeworm. To date, 

 mites in the families Galumnidae, Oribatulidae, Carabodidae, Notas- 

 pididae, Pelopidae, Liacaridae, and Haplozetidae have been found to 

 be vectors of various tapeworms. The species involved will be listed 

 under their respective families. This list is by no means to be consid- 

 ered complete, but merely an indication of the number of mites which 

 will probably be found to be vectors upon future study. 



To obtain a background for the study of the oribatids, it is necessary 

 to have available the early papers by H. E. Ewing, which covered the 

 taxonomy of these mites in the Illinois region; the various papers by 

 A. P. Jacot, which can be found listed in his obituary in the "Florida 

 Entomologist," Vol. XXIV, No. 2, pp. 43-47, 1941; the beautifully 

 illustrated papers by Frangois Grandjean of France; A. D. Michael's 

 two volumes, '^British Oribatidae," Vol. 1, 1881 and Vol. 2, 1883; 

 and the two excellent German publications, one by Carl Willmann, 

 "Moosmilben oder Oribatiden (Oribatei), Tierwelt Deutschland," 

 Vol. 22, pp. 79-200, 1931, and the other by Max Sellnick, 'Tormen- 

 kreiss: Hormilben, Oribatei, Die Tierwelt Mitteleuropas," Vol. 3, pp. 



