Rosy apple aphid meets its maker

摘要

Brian Lovelidge reviews the futher developments of Calypso. Roger Umpelby, former Adas fruit and hop entomologist. "Rosy apple aphid appears to be spreading and its severity increasing." Of the 40 or so pests that can undermine the economic performance of apple production, rosy apple aphid or blue bug ranks among the top few due to its devastating impact on fruit yield and quality. And while some orchards have so far escaped infestation, the pest appears to be spreading and its severity increasing,believes Roger Umpelby, Adas' recently retired fruit and hop entomologist. It has an extremely low spray threshold and unless it is well controlled the infested branches produce worthless, small, nodulous apples that in the case of cider varieties are difficult to remove at harvest and are too small to pick up. The pest's impact does not end there because it also weakens or kills the fruit bud, greatly reducing the following year's yield as a result, and unless totally controlled, will bounce back thenext season. The trouble is that the aphid initially gets established in the centre of the tree where it is very difficult to find. So by the time its presence is apparent it may have reached the leaf curling stage where it is much more difficult to control, even with aphicides with translaminar activity. Roger Umpelby says that another problem is that since the loss of the systemic OP's like Metasystox (oxydemeton-methyl) and Kilval (vamidothion), there has been virtually nothing sufficiently reliableand effective against rosy apple aphid.