Insects - Pests of Ornamental Trees, Shrubs and Flowers - page 232

562

Prays fraxinella (Bjerkander) ( 562-563 )
syn. P. curtisella (Donovan)
Ash bud moth
A generally common pest of ash ( Fraxinus excelsior );
damage to young trees is sometimes extensive. Present
throughout much of Europe.

DESCRIPTION
Adult: 15 mm wingspan; fore wings white, with
brownish-grey cilia and irregular blackish markings,
including a distinct triangular patch; head white;
antennae black; melanic forms, largely suffused with
black, also occur. Larva: up to 12 mm long; dirty
reddish green, with paler sides, more or less marked
with grey; head, prothoracic and anal plates black.

562 Ash bud moth ( Prays fraxinella ).

LIFE HISTORY
Adults occur in June and July, and deposit eggs on the
shoots of ash. Larvae commence feeding in the autumn.
They mine within the buds or leaves before
overwintering beneath the bark close to a terminal bud.
In the following spring they attack the terminal shoots,
boring into the pith. In May, growth from infested
shoots wilts, and affected tissue soon turns black. If
examined, a distinct hole may be seen at the base of
each wilted shoots and a larva found feeding inside.
Larvae complete their development by the end of May;
they then pupate, and adults emerge a few weeks later.
There is just one generation annually in northern
Europe, but two are completed in southern Europe.

563

DAMAGE
Growth from affected buds is aborted, and shoot
development then becomes forked as paired laterals
become dominant.

563 Ash bud moth ( Prays fraxinella ) damage to shoot of
Fraxinus .