Victoria plums in a Langstone, Hampshire garden have been affected by plum fruit moth larvae, despite a summer described as challenging for other fruit trees due to intense heat and lack of rain. While dessert and cooking apples yielded stunted fruit and quince trees were bare, the Victoria plum tree was heavily laden with fruit.
Upon inspection, the plums were found to contain small, vivid pink caterpillars, identified as the larvae of the plum fruit moth (Grapholita funebrana). These larvae burrow into the fruit, feeding on the flesh around the stone, and their presence can lead to a bitter taste and gritty texture, along with insect excrement.
The plum fruit moth is a drab, greyish-brown species common in southern England. Females lay eggs on developing fruit in mid-summer. Affected plums may appear slightly misshapen and can exude clear, sticky sap, a defence mechanism known as gummosis, from the entry hole.
To prevent the caterpillars from continuing their life cycle, advice suggests removing all dropped and damaged plums and disposing of them away from the tree.