the lily beetle

7/31/2019 The Lily Beetle

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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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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



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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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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.


Perhaps this ichneumon fly spotted on the lilies of Garden 65 was one of them.


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Defences


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


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.


The only other long term solution is GM flowers

the lily beetle

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