Insects - Pests of Ornamental Trees, Shrubs and Flowers - page 220

Parectopa robiniella (Clemens) ( 527 )
This North American leaf miner is associated with false
acacia ( Robinia pseudoacacia ). In Europe, infestations
were first reported in 1970 in Italy. Since then the pest
has spread to various other parts of central and southern
Europe, including Austria, Croatia, the Czech Republic,
France, Germany, Hungary, Romania, Switzerland and
the former Yugoslavia, where it is now firmly
established. Moths appear in May or June, eggs being
deposited singly on the underside of the leaves of host
trees. The larvae form large, irregular blotch mines on
the upper side of leaves (cf. Phyllonorycter robiniella ,
p. 232), which become very obvious and spoil the
appearance of infested trees. Unlike many related leaf
miners, larval frass is ejected through a small hole in the
lower surface of the feeding gallery. The outline of the
blotch mine is also, typically, digitate. Fully grown
larvae are 4.0-4.5 mm long and mainly green. They

pupate in white cocoons spun at the edges of leaves, and
moths emerge shortly afterwards. The adults (8-9 mm
wingspan) are mainly dark brown, the fore wings being
ornamented with several narrow, white, wedge-shaped
marks. In favourable areas there are up to three
generations annually. Fully-grown larvae of the final
brood overwinter within cocoons on fallen leaves.

Phyllonorycter maestingella (Müller) ( 528 )
syn. P. faginella (Zeller)
Generally common on beech ( Fagus sylvatica ), and
sometimes a minor pest of ornamental and nursery
plants. Present throughout central and northern Europe.

DESCRIPTION
Adult: 7.5-9.0 mm wingspan; fore wings dark brown,
with white, wedge-shaped markings; hind wings
greyish brown. Larva: up to 5 mm long; pale greenish
yellow, with a darker green gut; head light brown.
Pupa: 3 mm long; light brown.

LIFE HISTORY
Adults occur in two distinct generations, from May to
early June and in August. Eggs are deposited on the
underside of beech leaves. The larvae then develop in
brownish blotch mines formed on the underside of the
leaves between two lateral veins. The mines extend
from the midrib to, or almost to, the leaf edge, their
elongate form distinguishing them from those formed
on beech leaves by Phyllonorycter messaniella . Larvae
may be found in July and again from September to
October. Pupation takes place in the mine within a
white, silken cocoon; pupae occur in July and August,
and from November to May.

527

527 Mines of Parectopa robiniella on Robinia , viewed from
above.

DAMAGE
Mines cause slight distortion of the leaves but
infestations, unless heavy, have little effect on the
general appearance of hosts; they do not affect plant
growth.

528

Phyllonorycter messaniella (Zeller) ( 529 )
Zeller's midget moth
Generally common on holm oak ( Quercus ilex ) and
occasionally an important pest; deciduous oak ( Quercus )
trees, as well as beech ( Fagus sylvatica ), hornbeam
( Carpinus betulus ) and sweet chestnut ( Castanea
sativa ), are also attacked. Widespread throughout much
of Europe, except in more northerly areas; an introduced
pest of ornamentals in Australia and New Zealand.

528 Mine of Phyllonorycter maestingella in leaf of Fagus .