Insects - Pests of Ornamental Trees, Shrubs and Flowers - page 354

Allantus togatus (Panzer) ( 947 )
Widely but locally distributed on oak ( Quercus ); less
frequently found on birch ( Betula ) and broad-leaved
willows such as grey willow ( Salix cinerea ) and pussy
willow ( S. caprea ). Larvae feed on the leaves in the
summer and early autumn; they are sometimes found on
young trees but, owing to their late appearance, do not
cause significant damage. Fully grown individuals
( c. 15 mm long) are dirty greenish to greyish white, with
several small, white verrucae on the back and an
orange-yellow head; when at rest they curl into a ball on
the underside of the leaves, dropping to the ground if
disturbed. Fully fed individuals overwinter as prepupae
in rotting wood. Adults (8-9 mm long) are mainly
black, marked with yellowish white, and possess partly
cloudy wings; they occur from June to August.

fed in about three weeks; individuals then burrow into
decaying wood or the pith of pruned shoots to pupate,
each in a flimsy, semitransparent, greenish cocoon.
Adults emerge a few weeks later. Larvae of a second
generation feed from August to September or October.
They then spin cocoons but do not pupate until the
following spring.

DAMAGE
Although loss of leaf tissue disfigures host plants, and
might cause concern, the extent of damage is usually
insufficient to affect plant growth.

Allantus viennensis (Schrank) ( 948)
This species occurs in mainland Europe but not in the
British Isles, the larvae infesting wild and cultivated
rose ( Rosa ). Eggs are laid in the young shoots, usually
some distance from the tip. The young larvae feed
gregariously on the youngest leaves, forming distinctive
circular holes in the leaf blades. In their final feeding
stage they move downwards (then tending to occur
singly), often invading other branches. They then
typically devour tissue around the leaf margins. Larvae
are fully fed in 2-3 weeks. They then pupate in snags
or broken branches on the host plant. Individuals of the
final generation overwinter. Most adults appear in the
spring, but the emergence of some is delayed until
the summer. The larvae are relatively large (up to
20 mm long), with an orange-yellow head and a green
to bluish-green body, and the first, second and fourth
fold of each segment marked with prominent white
verrucae. Larvae may be found from June onwards
with, in favourable situations, up to three generations
annually.

947

947 Larva of Allantus togatus .

948

Amauronematus leucolaenus (Zaddach)
( 949-950 )
syn. A. saarineni Lindqvist
Locally common on willows, including common sallow
( Salix atrocinerea ), eared willow ( S. aurita ) and grey
willow ( S. cinerea ). Eurasiatic. Widespread in central
and northern Europe.

DESCRIPTION
Adult: 5.5-6.5 mm long; mainly black, with pale legs.
Larva: up to 18 mm long; elongate, green and shiny,
with small black verrucae; tracheae conspicuous.
Prepupa: green to yellowish green, with small, black
verrucae. 948 Larva of Allantus viennensis .