Biology Reference
In-Depth Information
Cacopsylla fulguralis (Kuwayama) ( 38 )
Elaeagnus sucker
In 1999, this eastern Asian species was found in
northwestern France on ornamental Elaeagnus
Psylla alni (Linnaeus) ( 40-42 )
Alder sucker
A common pest of alder ( Alnus ). Present throughout
northern Europe; also found in North America.
×
ebbingei plants. Since then, the pest has spread very
rapidly and has appeared in various other parts of
Europe, including the Channel Islands, England, Italy,
the Netherlands and Switzerland. Infestations appear to
be restricted to ornamental species of Elaeagnus ; they
have not been found on cherry elaeagnus ( E. multiflora )
or Russian olive ( E. angustifolia) .
DESCRIPTION
Adult: fore wings 3.8-4.8 mm long, clear but with dark
veins; body bright green, later developing brown or red
markings. Nymph: green, marked with black; antennae,
legs and wing pads pale yellowish brown to blackish.
LIFE HISTORY
Eggs are laid in bark crevices during the autumn and
hatch at bud-burst in the following spring. Nymphs then
feed on the young shoots, each developing within a
sticky mass of white waxy 'wool' amongst which beads
of honeydew accumulate. The nymphs are very active if
disturbed; they then scurry over the leaves or along the
shoots and might even drop to the ground. Development
is completed in the summer, adults occurring from June
or July to October. There is just one generation annually.
DESCRIPTION
Adult: fore wings 2.5-3.0 mm long, mainly hyaline,
clouded with grey; body pale greenish yellow, with
brown or greyish-brown markings; eyes reddish.
Nymph: pale greenish yellow or creamy yellow to
brownish, with greyish-brown markings; white waxen
plates often protrude from the hind end of the body.
LIFE HISTORY
Adults and nymphs feed on the underside of leaves.
They are very active, and move away rapidly if
disturbed. Little is known of the biology of this pest, but
several generations are completed annually.
DAMAGE
The presence of flocculent masses of 'wool' on plants is
unsightly, and infestations may reduce the vigour of
new shoots; damage, however, is rarely of significance.
DAMAGE
Infested plants are heavily contaminated with honeydew
and sooty moulds, which limits photosynthetic activity.
The pest also reduces plant vigour, and causes chlorosis,
dieback and premature leaf fall. Severe damage to
seedlings and established plants is reported.
Cacopsylla melanoneura (Förster) ( 39 )
syn. Psylla melanoneura Förster
Hawthorn sucker
Infestations of this widely distributed and generally
abundant psyllid are noted occasionally on cultivated
hawthorn ( Crataegus ). The greenish (orange- to
blackish-marked) nymphs feed on the young shoots
during May. Although sometimes present in large
numbers, they cause little or no direct damage; however,
by producing considerable quantities of honeydew and
white waxen threads, the pest often attracts attention on
nursery stock, hedges and specimen trees, particularly
in dry conditions. Adults are reddish to brown or
blackish (with characteristic whitish longitudinal
lines on the thorax). They are very active, and occur
throughout most of the year. Pine ( Pinus ) trees, upon
which they overwinter but do not feed or breed, are also
inhabited, as are various other non-host trees and
shrubs.
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