Sir, – May I bring to the attention of gardeners who grow lilies in their gardens the damage caused by a relatively new insect pest – the red lily beetle or lily beetle (Lilioceris lilii). Lilium species and hybrids, giant lilies (Cardiocrinum species) and fritillaries (Fritillaria species) can be extensively defoliated by the beetles and their larvae. The beetles are most active between March and October.
While this pest was widespread in Britain for three decades or more, to the best of my knowledge it was never a problem in our Irish gardens.
However, the beetles are thriving in our gardens now, having found their way here via imported consignments of bulbs and plants.
While some pesticides may help – beware not to spray the plants while insect pollinators are active – it is a good idea to check the undersides of the foliage of lilies on a regular basis for masses of grubs and adult beetles and remove the leaves.
Do not compost the leaves.
Having grown lilies for many years with no problem, it is such a shame these lily beetles are dreadful pests now. Vigilant gardening is called for. – Yours, etc,
MARY TOOMEY,
Blackrock,
Co Dublin.