July Tips & Advice

July Tips & Advice

Pest of the Month: The red or scarlet lily beetle (Lilioceris lilii) has become the lily growers’ nemesis. Both the adults and larvae can defoliate lilies (Lilium and Cardiocrinum) and fritillaries (Fritillaria). Adults are 8mm long, bright red with a black head and legs. Eggs are 1mm long and orange-red, found in groups on the underside of lily leaves. Larvae have orange bodies with black heads but are normally covered with their own slimy black excrement. The fully grown larvae are 8-10mm long. The pupal stage is in the soil. The beetle became established in Surrey in 1939 and it remained confined to south east England until the late 1980s. By the end of 2009 it has become widespread in England and Wales and is spreading in Scotland and Northern Ireland. Adult lily beetles emerge from the soil from late March to May. They feed and lay eggs on the underside of leaves of host plants from late April until early September. The eggs hatch after approximately a week. Beetle larvae can be found feeding on the foliage between May and the end of September. After about two weeks, when the larvae are fully grown, they pupate in the soil. Two to three weeks later new adults emerge. Despite claims in some literature, this beetle has only one generation a year. The beetles overwinter as adults in sheltered places, often in the soil but not necessarily near lilies or fritillaries. Courtesy of www.rhs.org.uk

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