Taro planthoppers (Tarophagus spp.) in Australia and the origins of taro (Colocasia esculenta) in Oceania

AbstractTaro planthoppers (Tarophagus spp.) may be associated exclusively or primarily with taro (Colocasia esculenta), and the geographical distribution of T. proserpina provides circumstantial evidence that taro is native to the Sahul continental region (as well as being native to Sunda). T. colocasiae (Matsumura) (Asche and Wilson 1989a,b) is reported here for the first time in Australia, and the genus Tarophagus is reported for the first time on the wildtype form of taro (C. esculenta). Three species of taro plant hopper are present in Asia and the Pacific. T. proserpina has a relatively narrow distribution extending from eastern New Guinea to Polynesia (Remote Oceania). This distribution adds support to the suggestion that Polynesian taros are derived from a Melanesian taro gene pool. It is tentatively suggested that different Tarophagus species evolved in association with different taro gene pools, before the domestication of taro in multiple regions within Asia and the Pacific. Plant viruses associated with taro and Tarophagus are also discussed.