• Parasitic wasps

  inside or on a host pest. Here's how it works: Egg laying: A female parasitic wasp seeks out a suitable host pest. The choice of host depends on the specific [...] of organic cultivation Biological control of aphids - Aphelinus abdominalis Biological control of aphids - Aphidius colemani [...] control. They are called "parasitic" because they lay their eggs inside or on harmful pest insects. These parasitic wasp larvae then develop inside the

• Two-spotted spider mite

  crops. Damage symptoms Larvae, nymphs and adults cause damage to the host plant by feeding on plant sap. They mainly occur on the underside of leaves where [...] 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 [...] photosynthesis, increased transpiration and reduced plant growth. As damage increases, whole leaves turn yellow, and as more cell sap is removed, the leaf, and

• Apple scab

  scab disease Damage symptoms Venturia inaequalis causes apple scab disease, which at first presents itself as lesions on blossoms, leaves, petioles and [...] infected fallen leaves or in lesions on twigs. These unripe fruiting bodies, or pseudothecia ripen in winter and form ascospores. Depending on the temperature [...] so the lesions remain smaller. Based on the research that has been done on the influence of climatic conditions on release of ascospores and risk of infection

• Aphipar

  Pests Especially for cotton aphid ( Aphis gossypii) ; tobacco aphid ( Myzus persicae var. nicotianae ); peach-potato aphid ( Myzus persicae var. persicae [...] mummies and females lay their eggs into aphids . The next generation of parasitic wasps develops inside the aphid, which converts into a leathery mummy. [...] site for at least a few days Dosage The dosage of Aphipar depends on climate, crop and aphid density and should always be adjusted to the particular situation

• Pierce's disease of grapevine

  denser and the leaves are a darker green than usual. Also, young infected trees show dwarfing. Leaves and flowers appear early and remain on the plant longer [...] limited to certain branches. When the leaves mature, slightly raised gummy lesions occur on the underside of the leaves. These lesions start out in a light-brown [...] desiccation of twigs and small branches occur on infected leaves. This usually starts in the upper part of the canopy on a few branches and then extends to the

• Bacterial canker of tomato

  leaves and fruits. Leaves and shoots wilt. On the lower leaves, blister-like white lesions occur, which later turn brown and may merge. The leaves wilt [...] years. On other fields on the same farm, no seed potatoes can be grown for one year after infection. Damage symptoms Clavibacter causes spots on stems, [...] brown but don’t fall off. On stems and shoots light stripes form, which then tear, allowing cankers to form. On tomato leaves, water-soaked lesions occur

• Pea blight, leaf and pod spot

  Ascochyta pisi causes spots on leaves, stems and pods of peas. The spots on leaves and pods are round, on the stems they are more elongated. The lesions are light [...] A scochyta blight on pea (leaf blight or pea blight) and lesions of stems, leaves, and pods (pea leaf spot and pea pod spot). Damage symptoms Ascochyta [...] by a dark brown to red-brown border. The first infection is often on the primary leaves. The fungus is seed borne and thus also causes post- and pre-emergence

• Bacterial spot

  bacterial leaf spot on peppers and tomatoes. Damage symptoms Xanthomonas vesicatoria in tomato causes small, water-soaked spots on leaves which are first round [...] spots may merge with lesions on the petioles and stems and form long dark streaks. On fruits, first small black specks are seen on green fruits. The specks [...] In pepper, the spots on the leaves are also round and small to start with and slightly raised from the leaf surface. They occur on the abaxial (underside

• Powdery mildew

  stomata on the underside of the leaf. On the upper side, yellow spots are noticeable. In case of a severe epidemic, the fluffy colonies also appear on the [...] side of the leaves. Many sweet pepper cultivars react to powdery mildew infection by dropping leaves that are not infected yet. It depends on the cultivar [...] first and foremost on the upper side of the leaves. In most crops, the white colonies later turn brown or grey. Severely affected leaves may turn yellow,

• Onion thrips

  throughout the world. It is found outdoors on many plants and particularly damaging on onions, leek, and in greenhouses on cucurbits, tomato, sweet pepper, eggplant [...] adult depends on the food source. Onion thrips (Thrips tabaci) usually pupate in the ground, although pupae can also be found on leaves, in flowers or [...] and pupal instars do not feed and only move if disturbed. Damage symptoms Thrips cause damage to plants by piercing the cells of the surface tissues and