Biology Reference
In-Depth Information
531
Phyllonorycter comparella
(Duponchel)
(
531-532
)
A local, southerly distributed and usually uncommon
species, associated with
Populus
, including aspen
(
P. tremula
). Not of importance as a pest but sometimes
noted on young amenity trees, particularly in mainland
Europe. The larvae mine the underside of the leaves,
forming relatively small blotches that cause noticeable
discoloration of the upper surface. Occupied mines
occur in mid-summer and in the autumn. Unlike most
species of
Phyllonorycter
the adults are mainly white
and grey, and the insect overwinters in the adult stage.
Phyllonorycter corylifoliella
(Hübner) (
533
)
Widely distributed and often common on rosaceous
trees, including crab-apple (
Malus
), hawthorn
(
Crataegus
), rowan (
Sorbus aucuparia
) and other kinds
of
Sorbus
; less frequently, birch (
Betula
) is also
attacked. The larvae feed throughout July and again in
September and October, each forming a large, silvery-
white, russet-flecked blotch on the upper side of leaves;
the mines commonly overlap the midrib or a major vein
and eventually cause infested leaves to crinkle. Fully
grown larvae are 5-6 mm long, with a brown head and
the body dirty whitish to pale yellowish but appearing
greenish inter-segmentally. Adults occur in May and
June, and in August. They are relatively large (8-9 mm
wingspan); the fore wings are chestnut-brown, suffused
with blackish scales and marked with two or three
narrow, whitish striae and a long, white basal streak.
531
Mine of
Phyllonorycter comparella
in leaf of
Populus
tremula
.
532
Phyllonorycter issikii
(Kumata)
This invasive Asiatic species has recently become
established in Europe, having spread rapidly westwards
into various countries, including Austria, Bulgaria, the
Czech Republic, Germany, Hungary, Italy, Poland and
Romania. The pest is associated with lime (
Tilia
), upon
which the larvae develop in small blotch mines formed
on the underside of leaves. The mines are relatively
small but clearly visible from above. There are two
generations annually; adults of the summer generation
are paler in appearance than those of the overwintering
(autumn) form, which have the fore wings heavily
marked with black.
532
Adult of
Phyllonorycter comparella
.
533
533
Mine of
Phyllonorycter corylifoliella
in leaf of
Sorbus
aucuparia
.
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