Biology Reference
In-Depth Information
Gonioctena viminalis
(Linnaeus) (
283
)
syn.
Phyllodecta viminalis
(Linnaeus)
Minor infestations of this beetle sometimes occur
on common sallow (
Salix atrocinerea
), grey willow
(
S. cinerea
) and other broad-leaved willows, damage
caused by the adults and larvae being similar to that
described for related pests such as
Phratora
spp.
(p. 144). The adults are 5.0-7.5 mm long and mainly
yellowish red, with a black head, black markings on the
thorax and 3-5 black spots on each elytron.
DESCRIPTION
Adult:
6-8 mm long; thorax and elytra red; head,
antennae, legs and underside of body black; thorax
relatively narrow, with a characteristic lateral
constriction.
Egg:
1 mm long; subspherical, red when
newly laid but soon turning brown.
Larva:
up to 10 mm
long; head black; body orange-red, with small black
plates on each abdominal segment; coated with black
slime.
LIFE HISTORY
Adults emerge from hibernation in the early spring and
may be found in association with host plants from
late March or April onwards. Eggs are laid shortly
afterwards. They hatch in 7-10 days and the larvae,
whose bodies often become coated with slimy black
faeces, develop rapidly, feeding ravenously for about
two weeks; they then enter the soil to pupate, each in a
silken cocoon. Young adult beetles emerge about three
weeks later. In favourable conditions, there are two
generations annually.
Lilioceris lilii
(Scopoli) (
284-286
)
Lily beetle
A destructive and invasive pest of Madonna lily (
Lilium
candidum
) and many other Liliaceae, including fritillary
(
Fritillaria
) and
Nomocharis saluenensis
. Solomon's
seal (
Polygonatum multiflorum
) is also attacked. Of
Asian origin and now present in much of Europe.
Widely distributed in Britain, and locally abundant.
Also present in northern Africa and North America.
283
284
283
Adult of
Gonioctena viminalis
.
284
Lily beetle (
Lilioceris lilii
).
285
286
285
Egg of lily beetle (
Lilioceris lilii
).
286
Larva of lily beetle (
Lilioceris lilii
).
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