Insects - Pests of Ornamental Trees, Shrubs and Flowers - page 261

655

Enarmonia formosana (Scopoli) ( 657 )
syn. Laspeyresia woeberiana (Denis &
Schiffermüller)
Cherry bark tortrix moth
A locally common pest of flowering cherry ( Prunus );
sometimes also damaging to crab-apple ( Malus ),
ornamental pear ( Pyrus calleryana 'Chanticleer') and
Sorbus . Widely distributed in Europe.

DESCRIPTION
Adult: 15-18 mm wingspan; fore wings more or less
brown, with a purplish sheen, and with irregular,
yellowish-orange markings and silvery-white costal
striae; hind wings dark brown. Egg: 0.7 0.6 mm; flat

and oval, whitish to reddish. Larva: up to 11 mm long;
brownish to salmon-pink, with brownish pinacula; head
light brown; prothoracic and anal plates light greyish
brown. Pupa: 7-9 mm long; light brown; tip blunt.

× 655 Male of Ditula angustiorana .

656

LIFE HISTORY
Adults appear from May or early June to September, the
extended emergence period giving the impression of
two generations. The moths are active in sunshine, and
often make repeated short flights to and from the
branches or trunks of infested trees. Eggs are laid singly
or in groups of two or three, usually on previously
infested or otherwise injured parts of trees, such as
frost-damaged or mechanically damaged bark, or
adjacent to pruning wounds. They hatch in two or three
weeks and the larvae then feed beneath the surface,
excavating irregular, often deep galleries in the bark; the
underlying cambium may also be damaged but tunnels
do not extend into the wood. Larvae are usually fully
grown by the following spring or early summer, passing
through five instars. Each then pupates in a silken
cocoon formed in the larval feeding gallery. Pupae
remain protruding from the bark after the adult moths
have emerged.

656 Larva of Ditula angustiorana .

657

DAMAGE
A considerable quantity of gum exudes from infested
parts of host trees and this, along with accumulations
of light-brown frass and silken webbing forced out of
cracks in the bark, may be one of the first indications of
an attack. Cherry trees are often invaded near the base
of the trunks, infestations producing cracks, swellings
and cankers; severely damaged trees may be killed.

657 Cherry bark tortrix moth ( Enarmonia formosana ).