Maggots spoils 'Victoria' Plum crop

A customer has just popped into the Plant Info Office explaining his 'Victoria' Plum has a wonderful crop of fruit (its the trees second year from planting), however most of the fruit is infested with small maggots. The question is what can he do about this problem for next year?

Chris replies:

A serious pest of the Plums is Plum Moth and the tell tale signs are a tiny hole in the Plum which is surrounded by a sticky glucose substance and inside the Plum is a creamy white grub which is the grub of the Plum Moth, and I am sure that this is the grub you are having problems with. What you will have to do next year is to spray your Plum Trees approximately 7-10 days after petal fall - using a contact insecticide such as deltamethrin (Bayer Sprayday Greenfly Killer) and hopefully the insecticide will kill the emerging grubs of the Moth before they have chance to enter the young plums.

We would also recommend placing a pheromone plum moth trap in place next April through to July and this may capture enough male Plum Moths to result in some females remaining unmated and unable to lay viable eggs. However, for this year it is important that you collect any infected plums and dispose of them.

Photo credit: RHS