Scarlet Lily Beetle
Scarlet Lily beetle - lilioceris lilii is a pest that as the name suggests, affects lilies by defoliating them.
The damage is caused both by the beetle and its larvae.
The beetles are 6-8 mm (¼”)long, bright red in colour, and have distinctive black legs and antennae, this makes them quite easy to spot on affected plants.
Scarlet Liy Beetle
Holes in leaves, stems and flowers, left by their small slimy black larvae, are often the first signs of infestation.
It is also said that the adults, when disturbed, emit a high pitch squeak which is assumed to be a warning to other beetles.
They emerge in spring, mate, and lay groups of orange eggs, 1.5mm (1/16”) long on the underside of leaves
Adults will continue to mate and feed from spring until autumn.
The eggs take a week to hatch and are produced continually until the end of August.
Lily Beetle Eggs
The grubs are dirty orange and often covered with their black slimy excreta.
They have black heads and three pairs of legs on their upper body.and reach 8-12mm (¼”-½”) in length.
They feed for two weeks on the underside of leaves working from the tip of the leave, and working back to the stem, once fully fed they drop into the soil to pupate.
Adults overwinter in sheltered places adjacent to host plants and emerge in late-March to early April.
Lily Beetle Grub
Organic control: can be difficult,and prevention is often the best cure.
Plants should be inspected regularly and any beetles / larvae should be removed by hand.
To do this, encourage insect-eating birds into the area by providing bird feeders and nesting boxes.
Re-pot susceptible plants in fresh compost in early spring before the overwintering adult beetles emerge from the soil.
Chemical control: use a suitable pesticide based on natural fatty acids.