pests and diseases

Integrated Pests and Diseases

ManagementBotanical Garden

MAICh

Presentation by

Nicolas Valanides

2016

SUMMURY

I. Roses

II. Citrus

III. Grape Vines

IV. Carob Trees

V. Palm Trees

VI. Fig Trees

VII.Olive Trees

VIII.Ornamentals

I. Roses : Rosa spp.• A. Fungi

1. Powdery Mildew- Podosphaera pannosa

2. Rose Rust-Phragmidium tuberculatum

3. Downy mildew of roses-Peronospora sparsa

4. Black spot -Diplocarpon rosae

5. Botrytis – Botrytis cinerea

6. Canker- Coniothyrium spp.

Vs

A1. Powdery Mildew disease• Pathogen: Podosphaera pannosa (also in Prunus spp.)

• Found everywhere- soil, air, plant debris-different forms(spores, rusting spores, mycelia)

• Spring/new vegetative growth: Warm days +cool nights + 50-70 % RH (unlinke other fungi)

• Symptoms: White powder on leaves & stems => already invaded the plant tissues causing serious damage

American Rose Society

Diagnosis of Powdery Mildew

1.Beginning of symptoms- the powder is actually the mycelia of the fungi2.It spreads progressively in both sides of the leaves (depending on the species)3. Eventually the leaves will end up curled, white to yellow and destroyed.4. Difference between health and infected leaves

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4American Rose Society

Controlling of Powdery Mildew

• Cultural practices: 1. Excellent air circulation provided by pruning (the center

should be as open as possible), striping dead or diseases leaves, spacious distance between plants.

2. Take away or destroy debris

3. Keep away from other susceptible plants, such as weeds.

4. Apply thick layer of mulch-compost to prevent spores from sprouting- also works good for thrips

5. Water should be mitigated in order to be available as free water and not as RH, humidity in the air or in the soil=prevents spore germination. Thus, watering should be in the morning hours, preferably high-pressured.

6. Spraying in a dormant stage, wipes out last years spores


Controlling of Powdery Mildew• Cure is succeeded only with prevention, against rapid

growth

– Create a protective coat between fungi-plant tissues

– Application MUST START BEFORE spore germination

– Spray every 7-10 days, according to the cover period

– Fungicides as prescribed by the agronomists

– Baking soda - Safer® Sunspray- not to be applied in the heat, nor rain or in high concentrations

– Anti-Transpirants prevent moisture loss from the leaves- not yet licensed


A2.Rose Rust Disease• Pathogen: Phragmidium tuberculatum

• Symptoms: Spring-Summer– Stem: Spring occurrence leads to distorted young

green stems, with large pustules of bright orange dusty spores

– On leaves: Yellow spots-upper surfaces=> pustules of dusty orange spores on the lower surface. Late summer, the orange pustules turn black. Infected leaves may fall early.

Royal Horticultural Society

Controlling Rose Rust• Prune out spring infections, to prevent the spread of spring

spores

• Collect and destroy fallen leaves in autumn or apply soil mulching=> reduce the number of overwintering resting spores

• Change to a resistant cultivar

• Fungicides as prescribed by the agronomists


A3. Downy Mildew Disease

• Pathogen: Peronospora sparsa

• Reoccurs in the right conditions in spring (RH>85%, 26 °C), mainly as an epidemic disease.

• Spores may survive and be viable, on fallen leaves for as long as a month, but temperatures of over 26 °C for a 24-hour period will kill all active spores.

• Once it takes hold, it will defoliate a plant very rapidly

• It is extremely contagious pathogen (epidemic disease)

• The symptoms of downy mildew are frequently confused with those of blackspot


A3.Downy Mildew Symptoms1. Leaves have flat, angular, reddish-black spots, formed between the leaf veins.2. Plants are rapidly defoliated3. Appearance of symptoms, despite early and regular use of a blackspot-effective fungicide.4. Appears during periods of moderate temperatures and high humidity.


A3. Downy Mildew Treatment• Fungicides

– Dithane T/O(turf & ornamental) , Protect T/O, when applied to both sides of the leaves.

– Aliette (fosetyl aluminun), Subdue 2E or Subdue Maxx (copper metalaxyl), Stature DM (dimethomorph )

• Severely prune back those bushes that were heavily infected and defoliated, soon after the chemical treatment.


A4.Black Spot Disease

• Pathogen: Diplocarpon rosae• Infects the leaves and greatly reduces plant

vigour.• The black spot lesions are spores, on the upper

leaf surface and can be spread with water.• The fungus spends the winter in resting

structures on fallen leaves, in dormant infections, on young stems and buds.

• In spring it produces spores to infect young foliage. It can be very persistent, as long as the leaves remain on the plant during wet conditions.


A4.Black Spot Symptoms

1. Leaves have black and yellow “rounded” spots. The spore can cross between leaf veins.2. Plants are slowly defoliated.3. Early and regular fungicidal use results in an absence of symptoms.4. Appears anytime, endemic, not epidemic.

5. Small, black, scabby lesions may also appear on young stems


A4.Black Spot Treatment

Non-chemical control• Collect and destroy fallen leaves in the autumn, or bury

under a layer of mulch. • Prune out all stem lesions in spring before leaves

appear. • Resistant varieties.Chemical control• The fungicides tebuconazole (Bayer Fungus Fighter

Concentrate), tebuconazole with trifloxystrobin (Bayer Fungus Fighter Plus), and triticonazole (Scotts Fungus Clear Ultra and Scotts Fungus Clear Ultra Gun) are labelled for the control of rose black spot.


A5. Gray mold or Botrytis Blight Disease• Pathogen: Botrytis spp.

• Mainly attacks tender tissues, such as flower petals, buds or seedlings; weakened or injured tissues (such as pruning cuts) or aging and dead tissues. Actively growing tissue is seldom affected, except of flower petals.

• Outdoors the fungus overwinters on decaying plant material and in infested soil. Sclerotia are the main structures for surviving outdoors at 4-31οC.

• Anything that moves soil or plant debris can spread the overwintering stages. Sclerotia germinate they give rise to conidia (gray-brown powdery spores) or an infection hyphae. The conidia are then dispersed in large numbers by air currents or splashing water to new plants. Then conidia penetrates/infest the plant tissue.

• The optimal temperature for germination of the conidia is 22- 25 oCwith free water or with RH=90-100%.


Biological cycle of Botrytis spp.

Symptoms of Botrytis Blight

Ghost spots

Grey mycelium growing on flowers & stems

Leaf spots

Petal deformation

Controlling Botrytis Blight

• Strict sanitation with removal infected plant material, which should be placed in the trash or burned and never placed in a compost pile.

• Water in the morning, avoiding splashing water on foliage

• Space plants to provide for maximum air circulation.

• Avoid over-fertilization and unnecessary wounding of plants.

• Fungicide should not be used more than two consecutive times without rotating to another effective chemical. These chemicals should be from different classes.

• Some of the most effective chemicals are from the following four different classes: Chloronitrile class – chlorothalonil (DaconilUltrex); Dicarboximide class – iprodione (Chipco 26019) and vinclozolin (Curalan); Hydroxyanilide class- fenhexamid (Decree) and Phenylpyrol class – fludioxinil (Medallion)

• Should be applied prior to the development of disease.American Rose Society

A6.Stem Canker Disease• Pathogen: Coniothyrium spp.

• Can eventually kill your rose plant

• Show up after pruning, especially when the pruners have not been cleaned/sanitised between the prunings of different rose bushes.

• Canker is most active during cold times , when rose bushes are less active.

• Symptoms: Black splotches on the canes of rose bushes.

Gardening Know How, http://www.gardeningknowhow.com/ornamental/flowers/roses/rose-canker-fungus.htm

http://www.gardeningknowhow.com/ornamental/flowers/roses/rose-canker-fungus.htm

Stem Canker Prevention & Cure

• Removal of the infected canes, down to healthy cane tissue below the canker, followed by the spraying of a good fungicide =>getting rid/ reducing the canker problem.

• Wipe off the pruners with the disinfectant wipes or dip them in the Clorox/chloride solution after each pruning of a diseased cane!

• Promote vigorous growth, as a healthy thriving rose bush fights off the canker attacks well.

• Using a good preventative fungicidal spraying program for elimination

• A rotation of fungicidal sprays is recommended to help keep the different funguses from becoming resistant to the fungicides effects

Gardening Know How, http://www.gardeningknowhow.com/ornamental/flowers/roses/rose-canker-fungus.htm

http://www.gardeningknowhow.com/ornamental/flowers/roses/rose-canker-fungus.htm

Rosa spp.

• B. Pest

1. Aphids- Macrosiphum rosae

2. Scales

a. Cottony cushion- Icerya purchasi

b. Red scale- Aonidiella aurantii

c. Rose scale- Aulocaspis rosae

3. Thrips

4. Caterpillars-Lepidoptera’s worms

5. Mites- Tetranychus urticae

B1.Aphids • Pest: Macrosiphum

rosae

• Hosts: Rosa spp., Rubus spp., Pyrus spp. Malus spp., Epilobiumspp.

• Characteristics: Large, Black head, green or pink

• They hatch from eggs => March-August cycle, includes asexual reproduction (wingless females)

www.plantwise.org

Aphid Symptoms & Cotrol• Control:

– Common Synthetic & Natural Insecticides– Decreased RH, N-fertilizers– Biological Control with other insects/predators/natural enemies

such as lady bugs.• Symptoms:

– Growing point/inflorescnence: distortion, dwarfing, honeydew, wilt, Black sooty moulds

– Leaves/stems: abnormal forms wilting, Black sooty mould– Virus vector=> no symptoms on roses

www.plantwise.org

B2. Scales: a) Cottony cushion• Pest: Icerya purchasi

• Hosts: Citrus, Roses and many weeds

• Cottony egg sac & honeydew production

• 1st & 2nd stage instars infest leaves and stems

• 3rd & 4th stage instars infest branches and trunk=>suck juice

• CONTROL

– Rodolia cardinalis (natural enemy)

– Oils (summer)

– ChloropyrifosUC Pest Management Guidelines

B2.b) California Red Scale• Pest: Aonidiella aurantii

• Hosts: Citrus, roses

• Feeds of from juices by sucking

• Shield: almost rounded shaped/protecting instars

• Female body: yellow-orange

UC Pest Management Guidelines

Controlling of Red Scale• Natural enemies: Aphytis melinus, A. lingnanensis (coastal

areas) and Comperiella bifasciata releases

– Consideration: avoid wide spectrum pesticides such as acetamiprid-Assail, Danitol-fenpropathrin, or beta-cyfluthrin-Baythroid

• Insect growth regulators

• Oil treatments

UC Pest Management Guidelines

B2.c) Rose scale

• Pest: Aulacaspis rosae

• Control:

– Prune & irrigate sufficiently

– Also see B2.b) Red Scale

UC Pest Management Guidelines,http://ipm.ucanr.edu/PMG/PESTNOTES/pn7408.html

B3. Thrips: Thysanoptera• Pests: A)Frankliniella occidentalis, B)Scirtothrips dorsalis• Hosts: Strawberries, Tomatoes, Peppers, Roses & other

ornamentals, Citrus• 2nd , 3rd instar and adults cause damage sucking juice and

scratching the surface• 4th and 5th instars mature in the soil

Control of Thrips

• Weed elimination after removal

• Balanced fertilization

• Mulching of the soil

• Yellow sticky tapes on the bottom of the plant

B4.Caterpillars: Lepidoptera

Control of Caterpillars• Regular Symptoms check ups

• Resistant cultivars

• Removal of caterpillars by hand, on spring

• Destruction of residues/weeds/infested plants(when is too much)

• Tracking with pheromone traps

• Pesticides: pyrethrum (biological), deltamethrin etc.

B5. Spider Mites: Tetranychidae• Pest: Tetranychus urticae

• Hosts: Solanaceae, Cucurbitaceae, Citrus, Ornamentals etc

• Diapause in the winter (cold &short days), starting from September

• Very active infesting and multiplying in the summer, starting from spring

• Best Conditions: 12-40°C (hot & dry)

Control of Two-spotted mite• Balance fertilizers, watering

• Keep dust and water in low levels

• Right pruning can keep RH with appropriate exposure to sun

• Natural enemy release: Phytoseiulus persimilis, Neoseiulus californicus

ΙΙ.Citrus

• A. Fungi

1. Phoma tracheiphila

2. Septoria citri

• Β. Bacteria

1. Pseudomonas syringae pv syringae

• C. Viruses

1. Citrus Tristeza Virus (CTV)

A.Fungi1. Phoma tracheiphilla

• Host: Citrus aurantii, C.limon, C.medica, C.sinensis etc.

• Produces toxic metabolites=> drying in 1-2 years

• Conditions: from open wounds, grows better at 20-25 oC, from October to February

• Slowly progress in the plants wood

Symptoms

• Drying & decline

• Brown wood

• Green parts turn to brown

Control

• Removal of unhealthy/dead parts• Removal of dead plants• Pruning after the raining season• Spray with copper in Octeber and

after raining of hail• Resistant varieties/rootstocks

A2. Septoria citri

• Epiphytic stage-lives on plants

• Penetrates from open gates

• Control: see A1

B1. Pseudomonas syringae pv syringaeCitrus Blast & blackpit

• Infects mostly every plant

• Lives and feeds on plants-saprophytic stage

• Infests plants-disease

• Penetrates from open gates/wounds in winter/spring, 12-20

• Develops good at 24-26

Control & Symptoms• Fence against the wind

• Pruning on time

• Spraying copper

• Precision on time fertilizing

C1.Citrus Tristeza Virus• Host: most of Citrus, Passiflora, Poncirus spp.

• Vector: Aphis gossypii, Toxoptera citricidus

• 4 strains

• Causes instead defoliation due to rootstock infections and death of the vascular bundles.

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Control

• Healthy & certified reproduction material

• Exclusion of the vector/virus, declaring protected zones

• Eradication & suppression of the virus

• Cross protection

• Resistant rootstocks

D. Citrus Pests• Hemiptera

• White flies-Aleurothrixus floccosus

• Aphids (Aphis craccivora , A.Fabae, A. gossypii, Aulacorthumsolani, Brachycaudushelichrysi, Macrosiphum euphorbiae, Myzus persicae, Toxoptera aurantii

• Diaspididae:Aonidiella aurantii, Aspidiotus nerii, Chrysomphalus aonidum, Lepidosaphes beckii, Parlatoriaoleae, P. zizyphi,

• Coccidae: Ceroplastes rusci, C. floridensis, Coccus hesperidum,Saissetia oleae

• Pseudococcidae: Planococcus citri

• Margarodidae: Icerya purchasi

• Leafhoppers: Empoasca sp

D. Citrus Pests

• Thrips: Frankliniella occidentalis -Heliothrips haemorrhoidalis -Pezothrips kellyanus Thrips tabaci

• Diptera: Fruit Fly - Ceratitis capitata

• Lepidoptera: Ectomyelois ceratoniae, Phyllcnistis citrella, Prays citri

• Acari: Aceria sheldoni, Eutetranychus orientalis, Panonychuscitri, Phyllocoptruta oleivora

D1. Aleurothrixus floccosus• Sucks juices, producing honeydews and black fungi

• Control : Cales noacki (natural enemy), imidacloprid, saponins, oils

D2. Toxoptera aurantii/ Aphis gossypii

• Control: See Roses

D2. Aonidiella aurantii/ Lepidosaphesbeckii

• Control: See roses

• Lepidosaphes beckii: Aphytis lepidosaphes as natural enemy

D3. Planococcus citri - Citrus Mealy Bugs• Hosts: Citrus,Grapes, Tomatoes and Cucurbitaceae

• Damage: Suck juices, producing honeydew

• Control: Leptomastix dactylopii (N.E), pruning, foliage arrangement, oils, chlorpyrifos, cypermethrin

• Vector for virus on grapes

D4. Mediterranean fruit fly: Ceratits capitata• Lays eggs almost in every soft fruit

• Larvaes feed of the flesh of the fruits

• Control

– International Pheromone Plastic McPhail trap (IPMT)

– Destruction of infested fruits

– Massive, Cover & Bait traps with pyrethrins (cypermethrin)

D5. Phyllocnistis citrella• Can survive the whole year

• Mainly infests the fresh leaves spring-autumn from larvaes

• Damage: serious when plants are young

• Control: Ageniaspis citricola, Citrostichus phyllocnistoides(N.E)

– Timing of fertilization(January), regulation of irrigation and vigor growth

– Flufenoxuron (15), imidacloprid (4A), oils when the infestation covers the 20% of foliage

III. Grapes- Vitis vinifera Diseases

• A. Fungi Diseases1. Downy Mildew- Plasmopara viticola2. Powdery Mildew-Uncinula necator3. Phomopsis viticola4. Grey mold- Botrytis cinerea (see Roses)

• Β. Βacteria Diseases1. Xylophilus ampelinus2. Xyllela fastidiosa

• C. Virus Diseases1. Grapevine Fanleaf Virus( GFLV)2. Grapevine Leaf Roll Disease( GLRaV)

A1. Downy Mildew- Plasmopara viticola• Endemic in wet regions after the raining seasons, between 11-

32 °C, from April-June

• Spray: Azoxystrobin-kresoxym-methtyl-trifloxystrobin,pyraclostrobin + boscalid, benalaxyl-metalaxyl,fosetyl-Al, *captan-mancozeb ziram-ferbam– 8-10 cm long shots(no *copper fungicides)

– After 10 days

– Just Before bloom

– After fruit set

A2. Powdery Mildew- Uncinula necator• Rests in the buds and grows on young- green, every year if

untreated

• 21-30 °C, low RH<90, low sugars

• Treatment: Application of sulfur– 18<T<30 oC morning or night

• 3 leaves

• Bloom

• Just after bloom

• Color break

Α3. Exocoriosis - Phomopsis viticola• Rests in wooden vines and grows on spring after cold and wet

weather, only on young parts

• Control:

– Proper pruning with disinfected tools

– Destruction of infected parts

– Fungicides

– Certified propagation material

B1. Xylophilus ampelinus• Chronic vascular infection: slow and mild symptom occurance

• Productivity decreases & brown vascular color change

• Brown Ulcers & hyperplasia & ripped bark

• Control: – Certified &healthy propagation material

– Avoid wounds & disinfect with spraying copper

– Right early pruning

– Removal of unhealthy parts

B2. Pierce Disease - Xyllela fastidiosa• Infects vascular bunds-xylem tissue

• Many strains on different hosts

• Hosts: Peaches, Almonds, Nerium oleander, Avocado, Pecan, Citrus, Spartium, Οlives

• Vectors: Cicadellidae and Cercopidae

• Reports in France an Italy- Potentially a very big thread

• Control:

– Healthy Certified Propagation Material

– Protected Zones

C1. Grapevine Fan Leaf Virus• 2 strains

• Chromogenic• Deforming

• Vectors: Xiphinema index & X.italiae• Control: Immuno-Certified Plant Material for

propagation

C2. Grapevine Leaf Roll associated Virus

• Strains: -1,-2,-3

• Vectors: Planococcus ficus, Planoccocus citri, Pseudococcus longispinus

• Control: Immuno-Certified Plant Material for propagation

III. Grapes – D.Pests

D. Lobesia botrana: Lepidoptera

• 3-4 generations grow between 10-30 °C, from April-Sepember

• 1st generation eats the flowers

• 2nd -3rd generation eats the fruits

• Damage: Decrease of production, bad wine

European grapevine moth: Lobesia botrana• Conjugation prevention

• Pheromone traps & degree days : check 100 grapes for each generation

– Indoxacarb , alpha cypermethrin, fenoxycarb , flufenoxuron, azadirachtin, pyrethrum , Bt

D2.Planococcus ficus/Planococcus citri

• Hosts: Figs, Apples, Citrus, Ornamentals, weeds

• Feed of the roots, produces honeydews

• Vectors of GLRV

IV. Carob Trees: Ceratonia siliqua

• Powdery Mildew: Oidium cerationiae

• Control: see roses

V. Palm trees: Phoenix theophrasti• Pest: Rhynchophorus ferrugineus

• Adults: Lays 200-300 eggs making holes on the tree bark, with their beak

• Larves dig holes and feed of tips & leave base, then make cocoon with the tree fibers

• Up to 21 generations when temperature and habitat are ideal

• Prefers P.canariensis

V. Control of Red Beetle

• Attractive pheromones & food on trees= capture with water

• Proper pruning without dead residues(Dec-Jan)

• Avoid wounds

• Destruction of unhealthy plants

• Pesticides: systemic from roots & or protective all over the tree( chlorpyrifos, dimethoate, diazinon,cypermethrin, imidacloprid & thiamethoxam )

• Natural enemy : Apple Steinernema carpocapse (nematode), every 40 days

Healthy Vs Unhealthy

VI. Fig Trees

• Α. Pests

1. Hemiptera: Ceroplastes rusci

2. Diptera: Silba adipata

3. Diptera: Zaprionus tuberculatus

4. Acari: Aceria ficus

• B. Diseases

1. Fig Mosaic Virus

A1. Ceroplastes rusci• Other hosts: Myrtus communis, Citrus, N.oleander, Morus

spp., Vitis vinifera

• 1000-1500 eggs/female/generation

• Suck juices & produces honeydews

• Control:

– Natural enemy: Eublemma scitula, Scutellista cyanea

– Oils

A2.Silba adipata

• Lay eggs on closed flowers causing problems to pollinators/pollination = rotting/unripe/dropping figs

• Control:

– McPhail traps

– Bait traps

– Removal of rotten figs

A3. Zaprionus tuberculatus

• Found in Myrtos, Crete on 2014

• Same damage as A2

• Many generations

• No licensed or scientific research on controlling, yet.

A4. Fig Bud mite- Aceria fici• Lives between the buds causing Bud blasting, impedance of

new growth, bud distortion and leaf chlorosis by sucking& scratching the leaves.

• Severe infestation may result in defoliation of branches or whole trees.

• Vector of Fig Mosaic Virus

Β1. Fig Mosaic Virus• Control of the vector

• Natural enemies: predacious mites-1) Pronematus ubiquitus, 2) Amblyseius swirskii and 3) Agistemus exsertus

• See also: Control of mites/roses

VII. Olives-Olea europaea

• A.Fungi

– Spiloceae oleagina

– Verticillium dahlia

• B.Bacteria

– Pseudomonas savastanoi pv. savastanoi

A1. Spilocea oleagina• Causes defoliation, fruit drop and tree decline in the summer

• Cold & wet weather

• Control:

– Copper Sprays

– Bordeaux mixtures

A2. Verticillium dahiae

• Hosts: Broad spectrum

• Hot conditions

• Infects from wounds, mainly from the roots

• Lives and grows in the wood

• Stops the flow of water in the xylem, causing drying and the quick or slow decline

• Control: – Healthy soil use

– Destruction of weeds

– solarization

Β1. Pseudomonas sevastanoi pv. sevastanoi• Damage: Loss of tree vitality, Drying of branches

• Enters through wounds in wet and windy weather

• Control: – Removal & destruction of infected parts

– Disinfect pruners and tools

– Healthy propagation material

– Copper spray for heavy infections

VII. Olives-Olea europaea

• Pests• Diaspididae: Aspidiotus nerii, Aonidiella aurantii,

Lepidosaphes ulmi, Leucaspis riccae, Parlatoria oleae, • Coccidae: Lichtensia viburni, Saissetia oleae, • Asterolecanidae: Pollinia pollini, Euphyllura olivina• Thrips: Liothrips oleae• Diptera: Bactrocera oleae, Dasyneura oleae, Prolasioptera

berlesiana, Resseliella oleisuga• Lepidoptera: Cossus cossus, Palpita• unionalis, Prays oleae, Zeuzera pyrina• Coleoptera: Phloeotribus scarabaeoides, Rhynchites

cribripennis

Aspidiotus nerii• Many hosts

• Sucks juices from every part, at wet and cold climate

• Control:

– Natural enemies: Chilocorus bipustulatus, Rhyzobiuslophanthae, Aphytis spp.

– See other Diaspididae

Parlatoria oleae

• Many hosts

• Red haloes on olives & less oil

• Control : see other Diaspididae

Saissetia oleae• Active from spring-autumn

• Feeds of small young parts of the olives, causing decline and defoliation

• Control: See other Coccidae

• Natural enemies: Chilocorus bipustulatus, Metaphycusbartletti, M. helvolus

Bactrocera oleae

• Only hosts: Olives

• Lays eggs on Juny-July in olilves

• The holes help other diseases to grow

• Control: See Ceratitis capitata

Phloetribus scarabaeoides

• Enters through open wounds as larva and feeds of the wood until it matures

• Control: – Destroy weak branches &Pruning

– Vigorous growth

– Chemichal : dimethoate

VIII.Ornamentals: Pistacia- Aphid gall• Baizongia pistaciae - aphid

• Spring: Sexual generation is layed as eggs and then winged Females Infest buds or small leaves and cause them to bend =>hypertrophy (increase incell size) and/or hyperplasia (increase in cell number)

• There they feed and reproduce asexually until autumn when they disperse as wingless aphids in the roots of grass

• Control: – Spray on Spring- Bud Break

– Removal of the galls

VIII. Carolina diaz Vs Stephanitis pyri

• Hosts: Apples, Pears, Roses

• Groups can cause serious damage

• Causes yellow lesions & black honeydew

• Control: cypermethrin (pyrethrum)

Symptoms on apples

VIII. Platanus orientallis Vs Downy Mildew

• Oidium platanii

• Control: See other Mildews

General tips

• Pests– Great unfriendly environment for pests

– Use traps and natural enemies

– Right pruning

• Diseases– Destroy/remove debris/alternate hosts/infected

areas

– Aeriation and sunlight, low RH, no wounds

– Right pruning for each plant

pests and diseases

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