• Early blight

  differ in specific symptoms. Damage symptoms Alternaria solani causes small green to dark brown spots to occur on leaves. Those spots then turn into dark [...] Conidia and mycelium overwinter in the soil and on crop residues and cause primary infection of the leaves. Survival can be several years, up to eight years [...] blight of potato and early blight of tomato, which presents itself as spots on leaves, petals and stems. These spots can be distinguished by the dark and brown

• Impatiens thrips

  from egg to adult on the plant, specifically on the leaves. Eggs are deposited in the leaf tissue, while subsequent stages are found on the upper- and undersides [...] Pupation occurs on the leaf rather than on the ground. The prepupae and pupae remain immobile on the leaf tissue. Adults are found on both upper- and [...] sweet pepper, cucumber and eggplants. It lives exclusively on the leaves and is often present on weeds in greenhouses. Life cycle and appearance of Impatiens

• Angular leaf spot

  well in dry leaves or leaves in the soil, but not independantly in the soil. Under humid conditions, bacteria ooze from the lesions on the leaves and form [...] spot disease found in strawberry. Damage symptoms Xanthomonas fragariae initially causes small, water-soaked lesions on the underside of the leaf. They enlarge [...] translucent. When conditions are humid, a viscous bacterial exudate forms on the underside of the leaf. This exudate changes to a white film when it dries

• Two-spotted spider mite

  Spider mite damage Larvae, nymphs and adults cause damage to the host plant by feeding on plant sap. They mainly occur on the underside of leaves where they [...] large dark spots on their body. Movement: Spider mites are slow-moving and tend to cluster on the undersides of leaves, where they feed on plant sap. They [...] dead cells become yellow, and in many plants the damage can also be seen on the upper surface of leaves as small yellow dots. The destruction of cells results

• Spider mites and other mites

  colonies on the undersides of leaves, where they feed on the plant's sap. The damage caused by plant mites can result in discolored or speckled leaves, stunted [...] underside of leaves can make them difficult to spot. Spider mite damage Some common signs of spider mite damage include yellowing or browning of leaves, stippling [...] stippling or mottling of leaves (small white or yellow spots), and webbing on leaves and stems. The leaves may also become distorted or curled, and the plant

• Tomato leafminer

  prefer leaves and stems, but they may also occur underneath the crown of the fruit and even inside the fruit itself. On leaves, the larvae only feed on mesophyll [...] nigrum. Damage symptoms The most distinctive symptoms of damage done by the tomato leaf miner ( Tuta absoluta) are the blotch-shaped mines in the leaves. C [...] Gelechiidae . It is oligophagous, feeding mainly on Solanaceae species . The main host is tomato but it also feeds on other solanaceous crop plants including potato

• Thrips

  often found on the undersides of leaves, where they feed on plant sap. Damage: Thrips can cause damage to leaves, flowers, and fruits by feeding on plant tissue [...] specks on the surface of leaves or flowers and can sometimes be mistaken for fungal spores or other types of debris. Thrips damage Thrips cause damage to the [...] With a serious infestation the leaves themselves can shrivel, and there can be varying levels of fruit damage depending on the species of thrips and their

• Greenhouse whitefly

  whitefly. It occurs on many crops, including aubergine, beans, cucumber, sweet pepper, tomato, roses, gerbera and poinsettia. Damage symptoms The larvae [...] expelling large quantities. The damage that whiteflies cause to a crop is the result of sucking out the sap from the plant leaves and secreting honeydew. This [...] very large, feeding on plant sap can affect the physiology of the plant, as a result of which growth is retarded. In full sunlight, leaves can wilt and fall

• Western flower thrips

  currently the most damaging thrips species in many greenhouse crops. The western flower thrips (Frankliniella occidentalis) can be found on a wide variety [...] occidentalis) usually pupate in the ground, although pupae can also be found on leaves, in flowers or in other sheltered places. The prepupal and pupal instars [...] disturbed. In the adults both pairs of wings are fully developed. Damage symptoms Thrips cause damage to plants by piercing the cells of the surface tissues and

• Horse-chestnut leaf miner

  miner damage leaves by feeding between the upper and lower parenchyma. The mine starts to turn yellow and later brown. By this time, the damage is very [...] continued unabated, causing aesthetic damage to horse-chestnut, one of the favourite ornamental trees in European cities. Damage symptoms Larvae of the horse-chestnut [...] leaflets, especially from July on, when the second and third generations develop. Trees with a low number of attacked leaves are not greatly affected, but