| Pathogen/Pest |
|
Species |
|
Affected plant material |
|
Symptoms |
|
| Scale
Insects |
|
Chloropulvinaria floccifera
Coccus hesperidium
Ceroplastes
sinensis
Planococcus citri
Aspidiotus camelliae
Hemiberlesia
rapax |
|
Leaves, young shoots and branches |
|
Several development stages (shields), most of them females, are found
on affected plant organs. Presence of sooty mold on the honeydew secreted by
the insect. Plant weakening. |
|
| Aphids |
|
Aphis gossypii
Toxoptera aurantii |
|
Young shoots, leaves. |
|
The
aphid colony can be observed mainly on growing shoots. Ants and sooty mold are
also present. Leaf curling is produced, mainly by T. aurantii. When colonies
are abundant, leaf chlorosis and plant weakening also takes place. |
|
| Thrips |
|
Heliothrips haemorrhoidalis |
|
Young shoots, leaves. |
|
SOn
affected plant tissue leaves become discoloured and present a silver dark
colour, the foliar apex may also distort. Small droplets of a black fluid can
be seen on leaves. |
|
| Weevils |
|
Otiorrhynchus sulcatus
Cneorrhinus dispar |
|
Leaves (adults), roots (larvae) |
|
Adults are active at night initially on tender and young shoots,
which present notch- shaped injuries along the margin. This damage subsequently
extends to more developed leaves. Larvae feed on roots. causing leaf weakening.
Plant seedlings growing at nurseries may die due to root system
damage. |
|
| Camellia
bud mite |
|
Cosetacus camelliae |
|
Flowers |
|
The
mite damages the bud and the flower causing a browning of the bud scales which
subsequently affects the whole bud. If the attack is important the flower bud
may fall. |
|
| Camellia leaf
mite |
|
Calacarus carinatus (Purple mite)
Acaphylla
steinwedeni (Orange mite)
Tetranychus urticae (Yellow
spider)
Panonychus ulmi (Red spider) |
|
Leaves |
|
Bronzed leaves. When a high population density of the mite attacks the plant,
leaves show mite exuviae that gives them a dusty aspect.
Bronzed leaves. When a high population density of the
mite attacks the plant, leaves show mite exuviae that gives them a dusty
aspect. Sometimes leaves show deformed margins and leaf curling to the
apex. |
|
| Camellia flower
blight |
|
Ciborinia camelliae |
|
Flowers |
|
First
symptoms show brownish spots on petals, which subsequently develop, affecting
the totality of the petal area, which presents a moist appearance. Affected
flowers usually fall to the ground (showing a ring of grey mycelia when sepals
are removed) although they may remain attached to the plant.
From May to
June, fruiting bodies can be observed growing under the organic material in the
soil. |
|
| Suden
oak death |
|
Phytophthora ramorum |
|
Leaves, shoots, stalks and buds |
|
Leaves show dark spots with diffused margins, generally presenting
concentring rings very apparent. Lesions can converge and affect the leaf
completely. Plant defoliation may take place. |
|
| Leaf
spots |
|
Pestalotia güepinii |
|
Leaves, twigs, and flower peduncles |
|
On
leaves, mainly on the apex and limb margins, large and brown spots which turn
into silver appear. On these spots, small black dots, which are the fungal
fruitful bodies can be seen. These spots can also appear on twigs, peduncles,
and flower calyxes. |
|
| Camellia
sooty mold |
|
Meliola cemelliae |
|
Leaves, shoots |
|
It
Develops on the honeydew secreted by scale insects and aphids and covers the
plant organs with a black layer. The plant experiences a general
weakening. |
|
| Anthracnose |
|
Colletotrichum gloeosporioides |
|
Leaves, twigs |
|
Twig
tips endure a progressive decay. On the leaf light brown spots appear. They
extend from the margin and darken. Fungus fruiting bodies appear, generally
forming orange concentric rings. |
|
| Root
diseases |
|
Phytophthora cinnamomi
Armillaria mellea
Rosellinia
necatrix |
|
Root system |
|
Roots do not present characteristic symptoms. The first signs of the disease
are chlorotic leaves. In a later stage defoliation may take place. A general
plant weakening is produced.
P. cinnamomi can produce striations and
necrosis on both root and collar. A white mycelia beneath the bark is observed
when A. mellea and R. necatrix attack the plant. |
|
| Camellia leaf
gall |
|
Exobasidium camelliae |
|
Leaves, flowers |
|
In
early spring, leaf limb thickens and folds. In a later stage the deformation is
more important and presents a creamy green colouration. The flowers show an
abnormal development and a light green colour with red areas. Subsequently they
present a thick and fleshy appearance. |
|
| Virus |
|
|
|
Leaves, flowers |
|
Irregular white yellowish patterns can be seen on leaf margin and limb.
Irregular white blotches appear on infected coloured flowers. Sometimes the
virus produces plant weakening. |
