Biology Reference
In-Depth Information
494
Family LYONETIIDAE
Small moths with narrow wings fringed by long cilia.
The larvae have a complete circle of crotchets on each
abdominal proleg.
Bucculatrix thoracella (Thunberg) ( 494-496 )
syn. B. hippocastanella (Duponchel)
Locally common on lime ( Tilia ), and of increasing
importance as a pest of amenity or shade trees in towns
and cities, particularly in Germany and the Netherlands.
Widely distributed in Europe.
DESCRIPTION
Adult: 8 mm wingspan; fore wings pale ochreous yellow,
with blackish markings; hind wings grey. Larva: up to
7 mm long; pale creamy white, with an orange tinge.
494 Larva of Bucculatrix thoracella .
495
LIFE HISTORY
Adults of the first generation occur in May, depositing
eggs on the leaves of lime. At first the larvae mine
within the leaves. Later they feed externally on the
undersurface, the change between instars occurring
beneath opaque, silken webs. When fully grown the
larvae descend on silken threads to pupate in ribbed
cocoons ( c . 5 mm long) formed on the trunks of trees or
on fallen leaves or amongst other debris on the ground.
A second flight of adults occurs in about July. Larvae of
this second generation complete their development in
late August or September. Pupal cocoons persist on the
trunks of infested trees for several seasons, some with a
split through which the pupa has burst on emergence of
the adult moth, and others with a rounded hole through
which a parasitoid wasp would have emerged.
495 Larval cocoon of Bucculatrix thoracella on underside of
leaf of Tilia .
496
DAMAGE
Infested leaves are extensively disfigured by whitish or
brownish patches, visible from above and from below.
In public places the larvae descending on their silken
threads are a nuisance, particularly on trees growing
close to market stalls and open-fronted food shops.
496 Pupal cocoon of Bucculatrix thoracella .
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