The occurrence and transmission of viruses of edible aroids in the Solomon Islands and the Southwest Pacific

The symptoms and distribution of virus diseases of taro (Colocasia esculenta) and other edible Araceae (Xanthosoma sagittifolium, Alocasia macrorhiza and Cyrtosperma chamissonis) in the S.W. Pacific are reported. Dasheen mosaic virus (DMV) occurred in many areas but, although two bacilliform virus particles that are damaging in parts of the Solomon Islands were found in some areas, with the exception of Santa Ysabel they did not cause the lethal disease which restricts the cultivation of some taro varieties on Malaita. DMV is transmitted by aphids and spread by vegetative propagation. The larger of the two bacilliform particles is transmitted by the planthopper Tarophagus proserpina and the smaller one by the mealybugs Planococcus citri and Pseudococcus longispinus. Hypotheses are proposed to explain our results and prospects for controlling these viruses discussed.