THE WATER MITES (ACARI, HYDRACHNIDIA) OF NEW-GUINEA

Seventy-five species are reported from New Guinea with descriptions of 19 new species and one new subspecies. The most widespread riverine g enera were Australiobates, Monatractides and Corticacarus. Corticacaru s was more frequent at mid and high altitudes, Albia at low altitude. The water mite fauna of New Guinea was predominantly Australian, only 2 of 29 genera were not found in Australia. The majority of species we re endemic (approximately 69%), 15% shared only with Australia, 9% onl y with Asia and 6% with both Australia and Asia. The high proportion o f endemic species was principally due to species radiation in four gen era: Australiobates, Albia, Corticacarus and Arrenurus. Webers line wa s the most likely line of discontinuity between the Asian and Australa sian water mite faunas.