Biology Reference
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407
408
407
Larva of willow rosette-gall midge (
Rabdophaga rosaria
).
408
Gall of willow rosette-gall midge (
Rabdophaga rosaria
).
409
410
409
Section through gall of willow rosette-gall midge
(
Rabdophaga rosaria
).
410
Old gall of willow rosette-gall midge (
Rabdophaga
rosaria
).
Rabdophaga rosaria
(Loew, H.) (
407-410
)
syn.
Rhabdophaga cinerearum
(Hardy)
Willow rosette-gall midge
A generally common pest of willow (
Salix
), especially
crack willow (
S. fragilis
), pussy willow (
S. caprea
) and
white willow (
S. alba
). Present throughout Europe.
LIFE HISTORY
Adults occur in late April or early May, depositing eggs in
association with vegetative buds. Infested buds develop
during the summer into leafy, cabbage-like rosette galls,
each containing a single larva (cf.
Rabdophaga
heterobia
). The galls eventually turn brown and remain
on the shoots throughout the winter. They are particularly
obvious in the early spring, just before the emerging new
green growth forces them to drop off; at this stage they
are sometimes referred to as 'camellia galls'. Larvae
overwinter within the galls. They then pupate in the
spring, shortly before adults emerge.
DESCRIPTION
Adult female:
2.2 mm long; head black; thorax
blackish to reddish; abdomen red; wings clear, 2.8 mm
long.
Larva:
up to 4 mm long; whitish to pinkish-
orange.
DAMAGE
The galls disfigure host plants and cause the death of
leading shoots, but tend to be of significance only on
small bushes.
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