• Tobacco aphid

  the leaves is reduced, affecting production. They are usually found in closely packed colonies, although they are also capable of dispersing through the [...] nymphs. They immediately start to feed on plant sap and grow rapidly. Aphids moult four times before reaching adulthood. With each moult they shed white [...] tobacco aphids ( Myzus persicae subsp. nicotianae ) are always pink or red. They appear matt, never glossy. Winged individuals have a brown-black head and

• Click beetles

  exoskeleton, with the head deeply retracted into the thorax. When disturbed they lie on their back feigning death and then suddenly propel themselves into [...] yellowish brown to black. The eggs are laid in May or June in groups in the soil. They hatch about one month later and the larvae start to feed on roots. The larvae [...] larvae (‘wireworms’) are long, thin, cylindrical and though skinned. They are up to 25 mm long and usually shiny yellowish brown or light brown with a darker

• Powdery mildew

  are all biotrophic fungi, meaning they feed on living plant cells and barely survive in the absence of a living crop. They survive as ascospores or perithecia [...] found yet for all powdery mildew fungi and especially in greenhouse crops they don’t play a role in the epidemics. Fungal spores germinate on the leaf surface [...] also protrude from the stomata. Conidia are the main means of dispersal. They are dispersed by wind, as are the ascospores. In general, powdery mildew

• Two-spotted spider mite

  damage to the host plant by feeding on plant sap. They mainly occur on the underside of leaves where they pierce the cells and suck out the contents. The [...] ) is a pest of many crops throughout the world. Despite their small size, they are capable of very rapidly doing severe damage, due to their great reproductive [...] can be distinguished. Eggs are usually found on the underside of leaves. They have an oval body that is rounded at the rear end. Their colour can vary

• Cotton bollworm

  instar larvae feed on soft leaves, creating small holes. When they reach the second instar, they can penetrate fruit through a small hole, often bored near [...] buds, flowers, fruits or on leaves. They are almost spherical with a flattened base and a diameter of about 0.5 mm. They are at first a shiny yellowish white

• Parasitic wasps

  insects that play a crucial role in natural pest control. They are called "parasitic" because they lay their eggs inside or on harmful pest insects. These [...] are highly specialized, with different species targeting specific pests. They are effective in reducing the population of harmful insects, making them [...] The choice of host depends on the specific species of parasitic wasp, as they often exhibit host specificity. The female parasitic wasp carefully inserts

• Cutworms

  with a dark head capsule and prothoracic shield, later they become earth-brown to dingy grey. They are about 1.5 mm long just after emergence and can reach [...] to grey-brown forewings with a faint kidney-shaped marking and a red spot. They have broad hindwings, evenly light or dark grey or orange-yellow with a broad [...] with close-lying hairs. The eggs are white at first but rapidly turn darker. They are laid separately or in batches on the ground, or on the plant close to

• Downy mildew of Cucurbits

  pathogens infect mostly the leaves but occasionally also stems and fruits. They cause lesions on the upper leaf surface, bordered by the veins, which are [...] mildew are not fungi but Oomycetes and related to Pythium and Phytophthora. They survive as oospores. From these oospores or surviving mycelium sporangia

• Bacterial wilt, brown rot

  collapse of plants happens rapidly. Leaves remain green after wilting, until they are completely desiccated. Infected stems show long, dark brown streaks. [...] Clavibacter -infected plants. In tomato, the youngest leaves are affected first. They show signs of wilting during the day which may disappear in the early stages [...] Disinfect cutting knives and tools Control root rot nematodes as the wounds they make on roots help the bacteria to infect the crop Do not use cut potatoes

• Crane flies

  called leatherjackets, live in the soil and feed on roots and shoots (which they pull into the ground of mainly grasses and cereal crops. The adults do not [...] Adult crane flies are large flies with females reaching 45-50 mm across. They have long, spindly legs and one pair of narrow, clear wings with clearly [...] soil, usually in the third instar stage. and start feeding again in spring. They become active again and feed voraciously when the soil begins to warm up