Abstract
It was shown that 17 out of 27 aphid species collected in the fields of Kagawa, Japan transmitted watermelon mosaic virus (WMV type 2). Eight aphid species, such as Aphis glycines MATSUMURA, Aulacorthum magnoliae (ESSIG et KUWANA), Aulacorthum nipponicum (ESSIG et KUWANA), Phorodon humuli japonensis TAKAHASHI, Rhodobium porosum (SANDERSON), Toxoptera citricidus (KIRKALDY), Uroleucon formosanum (TAKAHASHI) and Uroleucon (Uromelan) gobonis (MATSUMURA) were found to be new aphid vectors of WMV. Aulacorthum solani (KALTENBACH) and Rhopalosiphum padi (LINNÉ) were new to Japan. Four aphid species; Acyrthosiphon pisum (HARRIS), Aphis cracciaora KOCH, Aphis gossypii GLOVER and Myzus (Nectarosiphon) persicae (SULZER) transmitted the virus from diseased broadbean, garden pea, sweet pea and spinach to cucumber, or from diseased cucumber to these biennial crops. Since winter hosts of WMV have not yet been identified in western Japan where cucurbits do not grow in the winter season, the possible involvement of several winter hosts of the virus was evaluated.
