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The Lily Beetle
Lilioceris lilii
Scientific content for this presentation from RHS
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Garden 65 / June 2012
3 Description of Adult4 Taxonomy5-7 Description of Eggs, Larvae and Pupae8 -13 Life Cycle
14 Host Plants15 Distribution16 Who Eats Them?17 Defences18 Status as Pests19 So What Can We Do About Them?
Index
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A Lily Beetle in Garden 65
Adult Lily Beetles are 8mm long, with bright red bodies and black head and legs
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Garden 65 / June 2012
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Class Insecta (Insects)
Order Coleoptera (Beetles)
Suborder Polyphaga (Water, Rove, Scarab, Longhorn, Leaf and Snout Beetles)
Superfamily Chrysomeloidea (Long-horned and Leaf Beetles)
Family Chrysomelidae (Leaf Beetles)
Subfamily Criocerinae
Tribe Criocerini
Genus Lilioceris
Species lilii(Lily Leaf Beetle)
Lily Beetles are leaf beetles from theCriocerini tribe
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The eggs look like wild cherry flavoured Tic Tacs
Garden 65 / June 2012
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Larvae picked off the lilies of Garden 65
They are a dirty red colour and 8 10mm long
The larvae are normally covered in their own mucilaginous excreta
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Garden 65 / June 2012
The pupa is orange-red and glabrous with a denselymicrospiculate abdominal cuticle
Glabrous = smooth
Microspiculate = small spicules (spikey things)
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Life Cycle
Adults overwinter in plant debris
Emerge in spring
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Life Cycle
Mating continues until September
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Life Cycle
Eggs are laid under the leaves
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Life Cycle
Larvae eat leaves
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Life Cycle
And they continue upwards
Even eating the flowers and seeds
The buggers.
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Life Cycle
After 10 24 days they enter the soiland make cocoons
They develop into adults after 20 days at22C
Since Lily Beetles are becoming an increasingproblem in Britain is this necessary period of
20 days at 22C evidence of global warming?
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Larvae eat Lilies, Fritillaries, and Chinese Alpine Lilies
The adults will eat many other plants. This would explain theearlier chomping of the Fritillaries in Garden 65.
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Distribution
Lily Beetles are non-native.
A few were noticed at the endof the 19th century, but majorpopulations were only seen inthe mid- 20th century.
In the 1970s they wereconfined to the South East. By2000 they were in Cheshire and
Lincolnshire.
Today they are in most Englishcounties
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So Who Eats Them?
Shield Bug and Lacewing nymphs might.
Otherwise its a matter of a handful ofparasitoids infecting lily beetle larvae.And tellingly all of them are also alienspecies to the UK.
Garden 65 / June 2012
Perhaps this ichneumon fly spotted on the lilies of Garden 65 was one of them.
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Defences
Garden 65 / June 2012
The red colour, sequestered from host plants, is a warning
They can stridulate like grasshoppers at 200 chirps/min.This might be a defensive noise. Have you heard them?
They play dead, and are clever enough to land on their backs toincrease the effect. Drama queens.
The excrement cover of the larvae will put off generalist predators
(and me) but not the specialist flies
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Status as Pests
Garden 65 / June 2012
The RHS used to receive 4 enquires a year, now it is 101.
Lily Beetles are a nuisance to gardeners, but think of the impact oncommercial growers, and native plants.
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So What Can We Do About Them?
Pick them off
And that is all we can do
Some pesticides are available but theyare the notorious neonicotinoidsthat are harmful to bees.
The USA is testing biological controls
using those little flies, but thistakes time and money toinvestigate.
Garden 65 / June 2012
The only other long term solution is GM flowers