Plant Protection 3 : Selected Ornamentals, Fruit and Vegetables

Cineraria
Senecio hybrida
Family Asteraceae (daisy family)
PESTS AND DISEASES
Parasitic
Virus and virus-like diseases
Bacterial diseases
Fungal diseases
Damping off
Fungal leaf spots
Grey mould
Powdery mildew
Root and stem rots, wilts
Rust
White blister rust
Nematode diseases
Insects and allied pests
Aphids
Caterpillars
Cineraria leafminer
Snails and slugs
Non-parasitic
Environment
PESTS AND DISEASES
Parasitic
VIRUS AND VIRUS-LIKE DISEASES
Virus diseases recorded on cineraria include
cucumber mosaic virus and tomato spotted wilt
virus. See Annuals A 4.
BACTERIAL DISEASES
Bacterial wilt (Pseudomonas solanacearum). See
Vegetables M 6, Tomato M 98.
FUNGAL DISEASES
Damping off (Pythium spp.). See Seedlings
N 66.
Fungal leaf spots (Alternaria
Cercospora sp.). See Annuals A 5.
cinerariae,
Grey mould (Botrytis cinerea) may affect
young plants grown under high humidity and low
light intensity. See Greenhouses N 22.
Powdery mildew (Oidium sp.) may attack
leaves, stems and flower buds covering them
with a whitish, powdery growth causing stunting.
See Annuals A 6.
Root and stem rots, wilts
Fusarium (Fusarium spp.)
Sclerotinia rot (Sclerotinia sclerotiorum)
Phytophthora root rot (Phytophthora cryptogea)
Rhizoctonia stem rot (Rhizoctonia solani)
Verticillium wilt (Verticillium dahliae)
See Annuals A 6, Vegetables M 7.
Rust (Puccinia lagenophorae) may attack many
native and exotic Asteraceae including cineraria.
Pale yellow-green spots develop on leaves, stems
and flower stalks during warm humid weather.
See Annuals A 7, Calendula A 15 (Fig. 22).
White blister rust (Albugo tragopogonis)
occurs on cineraria, other Senecio spp. and other
Asteraceae. Light yellow areas develop on leaves;
later dome-like swellings burst to expose white
chalky spores. Foliage may die. See Gerbera A 37.
NEMATODE DISEASES
Root knot nematodes (Meloidogyne spp.) and
root lesion nematode (Pratylenchus sp.) have
occurred on Senecio spp.). See Vegetables M 10.
INSECTS AND ALLIED PESTS
Aphids (Aphididae, Hemiptera)
Cotton, melon aphid (Aphis gossypii)
Green peach aphid (Myzus persicae)
Leafcurl plum aphid (Brachycaudus helichrysi) is
pale to dark green or reddish brown.
Potato aphid (Macrosiphum euphorbiae)
Aphids may feed on new shoots. See Roses J 4.
Caterpillars (Lepidoptera)
Cineraria moth, senecio moth, magpie moth
(Nyctemera amica, Arctiidae) caterpillars feed openly
during the day on cinerarias (Senecio spp.) and
groundsels (Senecio spp.). They are 20-30 mm long,
hairy black with 2 tufts of hair projecting from the
head, with orange or occasionally blue stripes along
its back. They pupate on foliage in thin loosely woven
cocoons incorporating body hairs (Common 1990).
Looper caterpillars (Chrysodeixis spp.) may feed on
foliage of cineraria and many other plants. See
Vegetables M 13.
See Annuals A 8.
Cineraria leafminer
Scientific name: Agromyzidae, Diptera:
Cineraria leafminer (Chromatomyia syngenesiae)
Host range: Asteraceae, ornamentals, eg
chrysanthemum, cineraria, everlastings (Helichrysum),
gazania, nasturtium, vegetables, eg lettuce, weeds,
eg sow or milk thistle, cape weed, prickly lettuce.
Description and damage: Flies are grey, 3 mm
long and walk over leaves of hosts during winter
and spring. Larvae or maggots are creamy-white
and about 4-5 mm long when fully-grown. Pupae
are elongate, about 2.5 mm long and can be seen
through the epidermis on leaf undersurfaces. A
single leaf may contain several pupae. Maggots
tunnel between upper and lower leaf surfaces.
Initially mines appear as pale, narrow, thread-like
lines but as the maggots grow, mines become more
conspicuous and may reach 1.5 mm in diameter
(Fig. 36). In heavily infested cinerarias, growth
may be retarded or plants may die after most of the
leaves are destroyed. Foliage is spoilt.
A 28
ANNUALS AND HERBACEOUS PERENNIALS