Biology Reference
In-Depth Information
North America. Host plants include
Hydrangea
, lime
(
Tilia
), maple (
Acer
), plane (
Platanus
),
Viburnum
and
various rosaceous trees and shrubs. The brownish
female scales occur on the shoots, branches and trunks,
and their white ovisacs develop during the summer.
Following egg hatch, first-instar nymphs migrate over
the trees before settling down to feed and develop.
LIFE HISTORY
This species breeds parthenogenetically, with typically
two generations annually. Dense colonies occur on the
underside of the foliage of infested plants, the scales
tending to cluster along the midrib. Copious quantities
of honeydew are excreted.
DAMAGE
Infested host plants become extensively blackened by
sooty moulds that develop on the excreted honeydew,
and this has an adverse effect on photosynthesis and
growth.
Pulvinaria regalis
Canard (
221-222
)
Horse chestnut scale
An invasive Asian species, unknown in Europe before
the 1960s. Now widely distributed in central Europe and
elsewhere (including Denmark, England, France,
Germany, the Netherlands and Switzerland).
Polyphagous on various trees and shrubs, including bay
laurel (
Laurus nobilis
), dogwood (
Cornus
), elm
(
Ulmus
), horse chestnut (
Aesculus hippocastanum
),
lime (
Tilia
),
Magnolia
, maple (
Acer
),
Skimmia japonica
and sycamore (
Acer pseudoplatanus
).
Pulvinaria hydrangeae
Steinweden (
220
)
syn.
Eupulvinaria hydrangeae
(Steinweden)
Hydrangea scale
An invasive pest of ornamental trees and shrubs in
various parts of Europe, including Belgium, France,
Germany, Hungary, Italy, the Netherlands and
Switzerland. Also present in Australasia, Japan and
220
221
220
Hydrangea scale (
Pulvinaria hydrangeae
).
221
Horse chestnut scale (
Pulvinaria regalis
).
222
223
222
Colony of horse chestnut scale (
Pulvinaria regalis
).
223
Woolly currant scale (
Pulvinaria vitis
).
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