Pests and Diseases From Gall Wasps To Ivy Leaf Spot


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G
Common Name:- Gall Wasps
P_oakglwsp Gall Wasps is the name given to more than 1200 insects of many genus and species of the suborder Apocrita, family Cynipidae. These wasps usually have the typical thin waist between the thorax and abdomen. When the larvae of these wasps bite and ca...
Caused by:- Insects species of the Suborder: Apocrita Family:
Control:- Remove all infected stems by cutting back to well behind the galls ...

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Common Name:- Galls
P_galls Plant galls are abnormal growths of plant tissues and can be caused by a large variety of parasites, fungi, bacteria, insects, mites and damage to the plant. They are often highly organised structures from which the cause of the gall can often be ...
Caused by:- Many parasites, fungi, bacteria, insects, mites an
Control:- The exact cause of the galls must be determined before specific tre...

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Common Name:- Ganoderma Fungi
P_ganodermafungi There are several species of bracket fungi of the genus Ganoderma which causes of decay in the heartwood of a very wide range of tree and palm species all over the world. The rot is usually in the lower 4-5 feet of the trunk where the bracket frui...
Caused by:- Various species of Fungi from the genus Ganoderma
Control:- Apart from removing the bracket fruiting bodies to prevent the spre...

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Common Name:- Geranium Sawfly
P_geraniumsawfly1 A Greenish-grey, caterpillar-like larvae with black heads that live on the underside of Geranium leaves where they make rounded holes in leaves, but not in Pelargonium leaves, which are usually called Geraniums. Damage occurs during May to Septemb...
Caused by:- Protoemphytus carpini
Control:- Spray with a systemic insecticide, but usually the damage is only c...

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Common Name:- Geum Sawflies
P_geumsawfly At least three sawflies attack the leaves of Geums. One the Common Sawfly (Metallus lanceolatus) is a leaf miner that eats the leaves from inside. The tracks eventually merge together then dies leaving large brown patches on the leaves. The larvae...
Caused by:- A few Genus of insects from the Family Tenthredini
Control:- For the leaf-mining sawfly a systemic insecticide is probably the o...

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Common Name:- Gladiolus Corm Rots
P_gladioluscormrot It is a wonder that Gladiolus manage to grow and survive as the corms are affected by several fungi, bacteria and viruses which have deleterious effects on the corms:-

Dry Rot:-
Corms infected with the fungus Fusarium oxysporum f.s...
Caused by:- Various fungi and Bacteria
Control:- Control Management includes starting with healthy stock, removal of...

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Common Name:- Gladiolus Rust
P_gladrust Gladiolus Rust is caused by the fungus Uromyces transversalis and is an obligate parasite that only grows and reproduces on members of the family Iridaceae, including Gladiolus, Tritonia, Crocosmia and Watsonia spp. It primarily attacks hybrid cul...
Caused by:- The Fungus Uromyces transversalis
Control:- In the European Community the products permitted under organic regi...

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Common Name:- Gladiolus Thrips
P_gladiolusthrips Pear thrips, Taeniothrips inconsequens (Uzel, 1895) Picture by Pennsylvania Department of Conservation and Natural Resources - Forestry Archive, Bugwood.org.
Plants severely infested with gladiolus thrips looks spotted and bleached with sil...
Caused by:- The Insect Taeniothrips simplex
Control:- During winter the corms should be stored in cold temperatures which...

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Common Name:- Gleditsia Pod Gall Midge
P_gledpgallmidge Gleditsia Pod Gall Midge causes reddish galls to occur at the tips of the branches of the Honey Locust tree(Gleditsia triacanthos). Leaflets become pod-like where they have been damaged by the midge inside this pod the larvae continue feeding and ...
Caused by:- The Insect Dasineura gleditchiae
Control:- The severity of the attack depends to a certain extent on the varie...

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Common Name:- Gloeospporium Fruit Rot
P_gloeosporiumfrot Glomerella, or bitter rot, is a fungal disease which occurs on many fruit throughout the world. It is often referred to as a ‘summer rot’. It is caused by the Glomerella cingulata fungus which is the sexual stage of this fungus while the asexu...
Caused by:- The Fungus Glomerella cingulata
Control:- Warm, wet, humid conditions are ideal for the Glomerella fungus. Pr...

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Common Name:- Goosbeberry Sawfly
P_bsbrysawfly The common gooseberry sawfly larvae(Nematus ribesii) is one of at least three sawflies larvae that can strip the leaves from Gooseberry bushes in as little time as three weeks. Two others are the pale gooseberry sawfly (Pristiphora pallipes) and t...
Caused by:- The larvae of several Sawflies.
Control:- Continued vigilance is necessary as the sawflies are difficult to c...

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Common Name:- Gooseberry Dieback
P_gsberrydieback Gooseberry Dieback can be caused by at least two fungi Botrytis cinerea(Botryotinia fuckeliana) and Eutypa lata which usually attack grapevines. With Botrytis there is a greyish mould covering a branch or fruits eventually the branch dies back. Th...
Caused by:- Various Fungi
Control:- Pruning out infected branches and burn the cuttings. Spraying with ...

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Common Name:- Gooseberry Mildew
P_gseberrymldew There are two mildew that affects gooseberries and related plants as well as Botritis fungi. One is the American(Sphaerotheca mors-uvae) and the other is the European(Microsphaera grossulariae). American Gooseberry Mildew is a much more vigorous f...
Caused by:- Varius fungi
Control:- This fungus is encouraged by stagnant air around the branches and b...

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Common Name:- Gooseberry Rust
P_goosebyrust Gall produced by Nettle Clustercup Rust fungus Puccinia caricina DC. on common nettle Urtica dioica L.
The Genus Puccinia causes rust in many plants. In Gooseberry the species is P.Caricina which is a parasitic fungi that grow on gooseberry...
Caused by:- The Fungus Puccinia caricina
Control:- In the European Community the products permitted under organic regi...

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Common Name:- Gorse Seed Weevil
P_gorsesdwvil The Gorse Seed weevil Exapion ulicis (formerly Apion ulicis) is a species of straight-snouted weevil native to Europe. It was one of the first biological pest control against the spread gorse (Ulex europaeus) in New Zealand in the 1950s. The preda...
Caused by:- The Weevil Exapion ulicis
Control:- These pests do not cause enough damage to warrant spraying as the G...

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Common Name:- Grapevine Dieback
P_gpvinedieback Grapevine dieback usually does not happens until the vine has been growing for some years. In the spring when shoots from infected wood become stunted with small, chlorotic, distorted leaves. The leaves become more tattered as the season progresse...
Caused by:- The Fungus Eutypa lata
Control:- The disease is introduced into the vines during wet weather when sp...

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Common Name:- Green Spruce Aphids
P_greenspruceaphis Green spruce aphid Elatobium abietinum is a sap-sucking insect that infests spruce trees(Picea species). They are up to 2mm long and is dull green with dark red eyes and is most likely to be seen on spruce trees during Autumn to Spring. Eggs are p...
Caused by:- The Aphid species Elatobium abietinum
Control:- If the tree is not too large spray with insecticide, both knock dow...

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Common Name:- Greenfly
P_greenfly Greenfly is one of many species of aphids which suck the sap from leaves and stems and secrete honeydew which makes the leaves below sticky with honeydew which is the sugary sap of the plant. They attract ants and honeybees which feeds on the hone...
Caused by:- Several species of Aphids
Control:- Spray with insecticide, both knock down or systemic or wash plants ...

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Common Name:- Greenhouse Whiteflies
P_ghsewhiteflies The glasshouse whitefly is a common sap-feeding pest of houseplants and greenhouse plants like:- cucumber, melon, tomato, peppers, Chrysanthemum, Pelargonium, and Verbena. but there are several other whiteflies that tend to specifically attack oth...
Caused by:- The Insect Trialeurodes vaporariorum
Control:- Due to this pest's rapid reproductive rate there are widespread occ...

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Common Name:- Grey Mould
P_mildew1 Grey mould(also called Botrytis) is a disease usually caused by the fungus Botrytis cinerea(Botryotinia fuckeliana). This fungus has a diverse genetic variability(polyploidy) and some strains are specific to one type of plant. It normally affects ...
Caused by:- The Fungus Botrytis cinerea(Botryotinia fuckeliana)
Control:- Controlling this fungus is often difficult as it is so widespread s...

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Common Name:- Grifola frondosa
P_grifolafrondosa Grifola frondosa is usually, but not exclusively, a parasitic edible bracket fungi of the oak tree and gets its nutrients from the roots of its host. It is also known by many common names like Hen of the Woods, Ram's Head, Sheep's Head and Maitake...
Caused by:- The fungus Grifola frondosa
Control:- Apart from removing the fruiting bodies to prevent its spread. Ther...

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Common Name:- Ground Beetles
P_grndbeetles Ground Beetles also known as Carabid Beetles are mainly carnivorous and feed on other garden pests like aphids, caterpillars, slugs, snails, crane flies (leatherjackets), fruit flies, gall midges, many other garden pests. Therefore they should be ...
Caused by:- Various Carabid Beetles
Control:- As a general rule nothing needs to be done about ground beetles, bu...

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Common Name:- Gummosis
P_gummosis Gummosis is the abnormal production of a sticky gum or liquid in certain trees and fruits, esp stone fruit trees like plum, cherry and peaches. It has many causes and can be the result of wounding, infection by bacteria or pruning. Gummosis is mo...
Caused by:- Several Causes
Control:- To control this problem there must be several methods employed. Goo...

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Common Name:- Gypsy Moth
P_gypsymoth The gypsy moth caterpillars feed on almost any hardwood trees, with the exception of ash. when there is a large infestation they can cause immense defoliation of trees and conifers in an area leading to reduced growth and vigour and death of the a...
Caused by:- The Larvae of the moth Lymantria dispar
Control:- Phermone traps may be used to trap the males, Spraying with insecti...

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Common Name:- Hawthorn Button Top Gall Midge
P_hawthornbtgmidge Hawthorn Button Top Gall Midge is a common gall midge which lays its eggs in the shoots of Hawthorn in June. The developing larva produces a hormone which causes the developing shoots to develop into a rosette of small leaves instead of the normal...
Caused by:- The Gall Midge Dasineura crataegi
Control:- Spraying with an insecticide at the larval stage in order to preven...

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Common Name:- Hebe Downy Mildew
P_hebedwnmildew Hebe Downy Mildew is caused by the fungus Pseudoperonospora griesea and is not a true fungi but is more closely related to algae. Downy mildew will not usually kill the Hebe as it needs a living host to survive and reproduce. The growth is felt li...
Caused by:- The Fungus Peronospora grisea
Control:- The best method of control is prevention therefore good hygiene and...

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Common Name:- Hellebore Black Death
P_hellblkdth Hellebore Black Death is a relatively new disease, in the past 20 years, affecting Hybrid Hellebores. It is believed to be caused by a virus of the Carlavirus family given the name Hellebore Net Necrosis Virus (HeNNV).
The symptoms appear f...
Caused by:- The Virus Hellebore Net Necrosis Virus (HeNNV)
Control:- As with any plant virus infections there are no chemical controls.<...

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Common Name:- Helleborus Leaf Blotch
P_heleborelblotch Very few diseases affect Hellebores( Christmas Rose or Lenten Rose), but leaf blotch is an unsightly brown or black areas or blotches which appear on the leaves and stems of this plant. These blotches may merge leaving larger dead parts of the lea...
Caused by:- The Fungus Coniothyrium hellebori
Control:- It is often difficult to cure this fungus with fungicide therefore ...

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Common Name:- Hemerocallis Gall Midge
P_hmcallisgalmidge Very few things affect the Day lilies(Hemerocallis), but a major pest which seems to effect mainly the early-flowering Daylily buds is the Hemerocallis Gall Midge.
They are small flies which lays hundreds of eggs in the developing Daylily f...
Caused by:- The Larvae of the Insect Contarinia quinquenotata
Control:- Because they are inside the galled buds, larvae are protected from ...

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Common Name:- Hemispherical Scale Insect
P_hemisphscale Hemispherical scale insects is mainly a tropical pest, but it is also a pest in warm greenhouses and homes. It is a sap sucking insect that feed on plant juices and cause a loss of vigor and leaf deformations. Depending on the many host plant and ...
Caused by:- The scale Insect Saissetia coffeae
Control:- Small infestations can be rubbed off with the fingers. They are rel...

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Common Name:- High Temperature Damage to Plants
P_heatdamage Sun and Heat damage to plants can cause more subtle effects than those of extreme cold, which will kill a plant very quickly. Exposure to too much sun can generate very high temperatures in plant tissues, leading to dehydration and death of tissue...
Caused by:- Too much Sun
Control:- Once the damage is done there is little that can be done apart from...

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Common Name:- Holly Leaf Miner
P_hollylminer This pic shows the leaves of Ilex aquifolium with Phytomyza ilicis. There are several Phytomyza leaf miners some of which are particular to certain countries and specific Hollies. Phytomyza ilicis, is a European species and most hollies have some ...
Caused by:- The Larva of Phytomyza ilicis
Control:- Although the mines are unsightly, this pest can be tolerated as it ...

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Common Name:- Holly Tortrix Moth
P_hollytormoth This moth is a common species throughout the British Isles, occupying a wide variety of host plants. The adults are quite variable, and fly between June and September. They are active in the evening and later come towards light. It is also known a...
Caused by:- The Larvae of Rhopobota naevana
Control:- Insecticidal winter oil wash spraying should be effective in contro...

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Common Name:- Hollyhock Rust
P_hollyhockrust This rust fungus is a major problem of hollyhocks. It is caused by the fungus Puccinia malvacearum which only attacks Hollyhocks and their relative the common Mallow(Malvs rotundifolia). This infection is one of the major reasons why this wonderfu...
Caused by:- The Fungus Puccinia malvacearum
Control:- It is important to break the disease cycle and remove infected leav...

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Common Name:- Holm Oak Leaf Miner
P_holmoaklminer There are a few leaf miners that attack Holm Oak, but only one(Ectoedemia heringella) is specific to the evergreen Holm Oak. Two others are Phyllonorycter messaniel-la (Oak Leaf-Miner) which is more widespread and Stigmella suberivora (a micro mot...
Caused by:- Several Leaf Miner Moths
Control:- There is usually very little that can be done as insecticidal spray...

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Common Name:- Honey Fungus
P_honeyfungus1 There are many species of the saprophytic and or parasitic Honey Fungus(Armillaria). These fungi are some of the most destructive fungi for trees and other woody herbaceous perennials. One species(A. ostoyae) in the USA state of Oregeon is now est...
Caused by:- Several Species of the Fungus Genus Armillaria
Control:- Following the EU Directive 91/414/EEC on plant protection products ...

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Common Name:- Honeydew
P_honeydew Honeydew is a sugar-rich substance secreted by many sap sucking insects as they feed on a plant or tree. Their mouthpart penetrates the phloem of the leaf or plant and the high-pressure of the sap is forced into the gut of the animal. The insect u...
Caused by:- Various Sap Sucking animals
Control:- Spraying the plant with insecticide at the first sign of the sap su...

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Common Name:- Honeysuckle Aphids
P_honeysuckleaphid There are two species of aphids, a sap sucking insect, from the Genus Hyadaphis that are the most troublesome pests of honeysuckle. These are H. tataricae a white/cream aphid and H. passerinii a grey/green aphid.
The toxins released by the ...
Caused by:- Species of Hyadaphis aphids
Control:- Several things can be done to lessen attacks from this pest. In the...

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Common Name:- Horse Chestnut Bleeding Canker
P_hschntblcanker Horse Chestnut Bleeding Canker is a disease of the bark of horse chestnut which is caused by the bacterium Pseudomonas syringae pathovarv aesculi. It causes cankers which bleed a dark or reddish brown sticky fluid that ooze from cracks in the bark...
Caused by:- The Bacteria Pseudomonas syringae pv. aesculi
Control:- It is believe that this disease has been imported from India where ...

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Common Name:- Horse Chestnut Leaf Blotch
P_horsechstlfblotch Horse Chestnut Leaf blotch is a relatively common fungal leaf disease caused by fungus Guignardia aesculi. The initial infections looks like as water-soaked areas, starting at the edges of the leaf then darkens and spreads to the midrib. This area...
Caused by:- The Fungus Guignardia aesculi
Control:- The fungus survives in infected leaf tissues throughout the winter ...

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Common Name:- Horse Chestnut Scale
P_horsechstscale Horse Chestnut Scale(Pulvinaria regalis) is a sap feeding insect that feeds on several species of trees including Sycamore (Acer pseudoplatanus), Lime (Tilia), Magnolia(Magnolia species) and Horse Chestnut (Aesculus). It was first noticed in the U...
Caused by:- The Scale insect Pulvinaria regalis
Control:- As most of the host trees are very large it is often tolerated, but...

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Common Name:- Hosta Virus X
P_hostavirusx This virus is believed to have appeared around 1998 and has spread around the world like an epidemic. Hostas infected with Hosta Virus X usually, but not always. look weak, wilty and/or puckered. This virus affects different hosta cultivars in dif...
Caused by:- A relatively new virus
Control:- There is no cure and you should not compost infected plants as it r...

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Common Name:- Hoverflies
P_hoverflies Hoverflies are not pests, but are one of the gardeners best friends like the ladybirds and the lacewings, because the larva eats aphids and other soft bodied pests. The adults feed on pollen and nectar from flowers and some hoverflies are importan...
Caused by:- Several Genus and species of the family Syrphidae
Control:- Care should be exercised in the use of insecticides during the Spri...

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Common Name:- Hydrangea Leaf Spot
P_hydranglfspot There are many fungal leaf spot diseases of Hydrangeas. One very common one is caused by the fungus Cercospora hydrangeae others by Phyllosticta, and Colletotrichum fungi. All have similar signs and symptoms.. This fungal leaf spot can affect mos...
Caused by:- Several fungi, but mainly Cercospora hydrangeae
Control:- There are many fungal leaf spot diseases of Hydrangeas. One very co...

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Common Name:- Hydrangea Powdery Mildew
P_hydrpowmild Powdery mildews are one of the most widespread plant diseases. They affect virtually all kinds of plants from cereals and grasses, to fruit trees, and broad-leaved shade trees.
The symptoms are usually the same or very similar regardless of...
Caused by:- The Fungus Microsphaera polonica
Control:- The best method of control is good hygiene and growing conditions, ...

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Common Name:- Hydrangea Scale
P_hydrangscle This sap sucking scale insect also attacks other trees such as Prunus and Acer. The scale insects are most noticed in the early spring when the female lays the eggs under the leaves amongst a mass of white cottony waxy fibers. The egg masses are ...
Caused by:- The Scale insect Pulvinaria hydrangeae
Control:- The best way to deal with them is to spray with an insecticide in e...

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Common Name:- Inonotus Fungi
P_inonotusfgi Inonotus genus of fungi contain over 100 species which are parasitic/saprophytic mainly on broadleaf trees around the world. Most produce an annual fruiting body which has a felt-like upper surface starting off yellow/orange eventually turning bro...
Caused by:- Several species of Inonotus Fungi
Control:- The main way of avoiding these fungi is to avoid damaging the bark ...

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Common Name:- Iris Borer Caterpillars
P_irisborer Although these are not as yet in the UK it is only a matter of time before they may invade these shores. Iris borers(Macronoctua onusta) spend the winter as eggs on dead leaves, stalks and plant debris at the base of irises. In spring, they hatch ...
Caused by:- The Moth Macronoctua onusta
Control:- There are several things that can be done about this pest. First of...

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Common Name:- Iris Ink Disease
P_irisinkdisease This disease mainly attacks bulbous irises and a few other genus like Lachenalia and Tritonia. On the bulbs blue/black streaks, with raised margins, appear on the outer layers. Badly affected bulbs may rot or dry out. On the leaves initially chlor...
Caused by:- The Fungus Drechslera iridis
Control:- Destroy bulbs in which fleshy scales are affected and remove any i...

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Common Name:- Iris Leaf Spot
P_irislfspot Iris leaf spot is caused by a fungus called Mycosphaerella macrospora (formerly Didymellina macrospora or sometimes Heterosporium iridis) that is spread by wind blown spores or water splashes. It is more common during wet seasons and encouraged by...
Caused by:- Mycosphaerella macrospora
Control:- This fungus survives the winter on infected plant parts, therefore ...

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Common Name:- Iris Mosaics Virus
P_irismosicvir There seems to be many types of Iris Mosiac Virus, but the patogenic virus appear to be similar and also similar to Cucumber Mosiac Virus. Three types of Iris mosiac viruses are classified as affecting bearded virus depending on the severity of th...
Caused by:- Possibly several viruses
Control:- There is no cure or control other than to control the aphids and re...

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Common Name:- Iris Rhizome Rot
P_irisrhzmerot Iris Rhizome soft rot is often caused by the bacterial pathogen Erwinia carotovora. Usually the first sign you see is some of the leaves abruptly turning yellow and falling over. If you pull on the leaves you notice the rhizome at the base of the ...
Caused by:- The Bacteria Erwinia carotovora
Control:- If the infection is caught early enough cutting away the unhealthy ...

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Common Name:- Iris Rust
P_irisrust Iris rust is caused by the puccinia iridis fungus. It causes round to oval rust-colored pustules surrounded by a yellow margin. These spots can be present on leaves and stems, and initially do not kill the plant, but the leaves die prematurely an...
Caused by:- The Fungus Puccinia iridis
Control:- Spraying with a fungicide especially a systemic one should control ...

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Common Name:- Iris Sawfly
P_irissawfly The Iris Sawfly (Rhadinoceraea micans) is a black fly similar in shape to a hoverfly. These saw flies can be seen resting on the irises in late spring to summer. They seem to prefer waterside Irises especially the yellow variety. The larvae or cat...
Caused by:- The Sawfly Rhadinoceraea micans
Control:- Spraying with insecticides is possible where there is no danger fro...

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Common Name:- Iris Scorch
P_irisscorch Scorch is a pathological condition of bearded irises and the cause is unknown, but the bacterium Pseudonwnas that is also found in lilies is suspected to be the cause. The first sign of the disease is that the leaves, mainly at the center of the p...
Caused by:- Unknown cause, but Bacteria suspected
Control:- To avoid Iris Scorch dig up the affected plants and place them in a...

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Common Name:- Iron Deficiency
P_irondeficiency1 Iron deficiency is not a pest as such, but is a symptom that there is something wrong, usually with soil nutrients. It can easily be mistaken for manganese deficiency, but in this case all leaves are usually affected. All plants need iron to grow,...
Caused by:- Usually due to Soil ph being above 7
Control:- Iron deficiency can be avoided by choosing appropriate soil growing...

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Common Name:- Ivy
P_ivy Ivy is not a pest as such, but is considered so by many due to its fast growth and climbing action with self clinging roots. If left unchecked it will grow up trees and eventually block out the light and may even strangle the growth of the tree. I...
Caused by:- Fast Climbing Growth of Ivy
Control:- Annual pruning and removal of dead leaves is needed o keep it in ch...

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Common Name:- Ivy Leaf Spot
P_ivylfspot There are several bacteria and fungi that causes leaf spot on Ivy leaves. Bacteria enters through wound damage or through natural openings. usually it is the older leaves that develop water-soaked spots that turn brown then black. Some bacteria ca...
Caused by:- Various Fungi and Bacteria Xanthomonas spp.
Control:- To prevent leaf spot the most effective, apart from spraying with f...

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