Biology Reference
In-Depth Information
1030
1031
1030
Adult female of
Pristiphora testacea
.
1031
Larva of
Pristiphora testacea
.
1032
1033
1032
Adult female of
Pristiphora punctifrons
.
1033
Larva of
Pristiphora punctifrons
.
Pristiphora abietina
(Christ)
syn.
P. pini
(Retzius)
Gregarious spruce sawfly
Widely distributed and locally common on fir (
Abies
)
and spruce (
Picea
). Although regarded mainly as a
forest pest, damage also occurs on Norway spruces
(
P. abies
) intended for the Christmas tree market,
particularly when these are being raised near established
spruce plantations. The larvae (up to 15 mm long) are
green with a yellowish or brownish head. They occur in
May and June, and feed gregariously on the needles of
the new shoots. Infestations occur mainly at the top of
plants, sometimes causing distortion and shoot death,
and thereby reducing the quality of nursery trees.
onwards, and sometimes cause noticeable defoliation.
Fully grown larvae (15-18 mm long) are mainly yellow,
marked with black. There are up to two generations
annually. Adults (6.5-7.5 mm long) are mainly black;
they occur in May and June, and in July and August.
Pristiphora punctifrons
(Thomson) (
1032-1033
)
syn.
P. viridana
Konow
Minor infestations of this widespread species occur
occasionally on cultivated rose (
Rosa
), causing slight
damage to the foliage. The mainly black to dull greyish-
yellow adults (4-5 mm long) occur from April to May
or June. The larvae (up to 11 mm long) are green and
shiny, with a few small blackish plates dorsally on the
thoracic segments, pale yellowish thoracic legs and a
dirty-yellow, blackish-marked head; they feed on the
edges of the leaves in May and June, typically resting
with the tip of the abdomen curled downwards. Fully
fed individuals enter the soil, where they eventually
pupate. New adults appear in the spring.
Pristiphora geniculata
(Hartig)
Associated with rowan (
Sorbus aucuparia
) and locally
important as a pest of forest and ornamental trees;
widespread in mainland Europe, from Italy northwards,
but uncommon in the British Isles. Also present in North
America. The larvae feed gregariously from June
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