Biology Reference
In-Depth Information
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43
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Ash leaf gall sucker (
Psyllopsis fraxini
).
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Nymphs of ash leaf gall sucker (
Psyllopsis fraxini
).
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Psyllopsis fraxini
(Linnaeus) (
43-45
)
Ash leaf gall sucker
A common but minor pest of ash (
Fraxinus excelsior
).
Eurasiatic. Widely distributed in Europe; introduced
into North America.
DESCRIPTION
Adult:
fore wings 2.3-3.3 mm long, clear but with
brown veins and a blackish apical pattern; body pale
bluish green to pale yellow, marked with black.
Nymph:
pale bluish green; eyes red and prominent.
LIFE HISTORY
The winter is passed in the egg stage on dormant shoots.
The eggs hatch in the early spring, at about bud-burst.
Nymphs then feed on the young expanding leaves,
clustered together within rolled leaf edges (galls). They
secrete flocculent masses of white, waxy 'wool' and
also produce globules of honeydew. The galled tissue
turns yellow, changing through red and purplish to
brown, and such galls are most conspicuous from
summer until leaf fall. Adults appear from June or July
onwards, and often shelter within the galls along with
any later-developing nymphs. In common with other
psyllids, there are five nymphal instars; there is a single
generation annually.
45
Gall of ash leaf gall sucker (
Psyllopsis fraxini
) on
Fraxinus
.
Psyllopsis fraxinicola
(Förster)
Ash leaf sucker
This widespread and often common species is
associated with ash (
Fraxinus excelsior
), but does not
produce leaf galls. Adults are greenish or yellowish
green, with clear, unpatterned wings; the nymphs are
green (cf.
Psyllopsis fraxini
).
DAMAGE
The prominent leaf galls disfigure infested plants. They
potentially reduce the value of nursery stock but are
otherwise harmless.
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