gardening: Little red devils.
LILIES are one of my favourite summer-flowering bulbs, but this year my pots of beautiful Lilium regale have horrible scarlet visitors, the notorious lily beetle.
They are bright red - you can't miss them - with black heads, legs and undersides, and will eat the leaves and the flowers of your prize lilies from spring to autumn if you don't take action immediately.
The larvae are reddish blown with black heads, and covered in black excrement, and can sometimes be mistaken for bird droppings. With adequate food, they reach 8-10mm in length.
Scarlet lily beetle (Lilioceris lilii) has become a serious problem for those who grow lilies and fritillaries in this country.
It originated in the Mediterranean, also occurring in China and northern India, but was sighted on our shores at the end of the 19th century, becoming established in the 1940s in a private garden in Surrey and from there spreading throughout the country.
In recent years, it has also reached Scotland.
It is believed that the warmer weather we have experienced in recent years has enabled it to move farther afield, as it seems more likely to fly on hot, sunny days.
Both the bright red adult and the somewhat slug-like larvae can cause severe damage to foliage and flowers.
The Royal Horticultural Society continues to monitor the spread of the beetle and to investigate its lifestyle with the aim of determining the best control measures.
Adults emerge from the soil in April and May.
They feed and lay their eggs on the underside of leaves of host plants from late April until early September.
The eggs hatch after seven days.
The beetle larvae feed on the foliage between May and the end of September.
After two weeks, when the larvae are fully grown, they are able to pupate in the soil.
Two to three weeks later, the adults emerge and complete the life cycle.
Only one generation is produced in a season.
Once lily beetles have a hold on your lilies, they are difficult to control because of their long egg-laying and emergence period, which runs from mid-spring to mid-summer.
If you only grow a few lilies, the beetles can be picked off by hand.
If you grow a lot, you may have to use a spray based on imidacloprid.
If your lilies are in flower and you need to spray, do it at dusk to avoid harming bees. The beetle grubs are more susceptible than the adults, which are protected by their hard coats.
A red Lily Beetle which will eat the leaves and flowers of lilies, if immediate action is not taken