• Pea leaf miner

  oval and hard to distinguish from feeding spots. The larvae of Liriomyza huidobrensis are transparent dirty white. When the larva hatches from the egg, it [...] ly damaging to leaf vegetables and causes problems especially in lettuce grown on open ground. Damage symptoms Leaf miners cause damage to plants both [...] directly and indirectly. The most direct damage is caused by the larvae mining the leaf tissue, leading to desiccation, premature leaf-fall and cosmetic damage

• Apple scab

  ascospores mature from bud break onwards. During wet weather, mature ascospores are released from the pseudothecia and carried by wind to newly emerging leaves [...] support. Management should aim to limit primary (ascospore) infections in spring and reduce overwintering inoculum to prevent severe epidemics. Cultural [...] of high apple scab infection risk by combining leaf wetness duration, temperature, and rainfall. This enables growers to optimise treatment timing, reduce

• Pea blight, leaf and pod spot

  more elongated. The lesions are light brown, sunken and surrounded by a dark brown to red-brown border. The first infection is often on the primary leaves [...] the lesions, pycnidia are formed from which orange-red masses of two-celled conidia are exuded. Secondary infection is by splash dispersal of these conidia [...] at temperatures below 20 °C and the spores require water for dispersal. How to prevent Pea blight, leaf and pod spot Grow peas in arid regions Use clean

• Mealybugs and scales

  leads to sooty mould. Infestations reduce plant vigor, fruit quality and overall yield. Effective control of mealybugs and scales is essential to maintain [...] the sap of plants and are mostly host plant specific. Apart from the damage they cause by sucking plant sap, mealybugs and soft scales also produce honeydew [...] females extract the sap from the plant, stunting growth and causing deformation and/or yellowing of leaves, sometimes followed by defoliation. The overall

• Bugs

  bugs Bugs can cause extensive damage to greenhouse and field crops by feeding on plant tissues and fruits, leading to deformation, discoloration, and yield [...] s bugs damage plants by puncturing leaves and growing points with their piercing-sucking mouthparts and extracting nutrients from them, resulting in d [...] yield loss. Effective bug control is key to maintaining healthy, high-quality crops. Biological control of bugs combines targeted monitoring and natural

• Loose smut of barley

  Infection mostly occurs before pollination and within one to two days after pollination. How to prevent Loose smut of barley Use clean seed: Apply systemic [...] infected seed and prevent the use of seeds from infected fields for further cropping Prevent plant diseases by optimizing plant potential and crop resilience [...] also known as barley smut, or loose smut of barley. Damage symptoms Infection by Ustilago nuda f. sp. hordei r emains invisible until head emergence. The first

• Black bean aphid

  wide range of other crops. Damage symptoms Economic damage by black bean aphid is mainly due to direct feeding damage. Indirect damage is caused through [...] extract nutrients from the plant and disturb the balance of growth hormones. As a result, the plant’s growth is retarded giving rise to deformed leaves or [...] sugars, but has a low protein content. Aphids therefore need to extract large quantities of sap to get sufficient protein. The excess sugar is secreted in the

• Two-spotted spider mite

  urticae ) is by far the most important species in greenhouses and many outdoor crops. Spider mite damage Larvae, nymphs and adults cause damage to the host [...] that is rounded at the rear end. Their colour can vary from orange, light yellow or light green, to dark green, red, brown, or almost black. Males are smaller [...] narrower and more pointed at the rear. Colour is very variable: from light yellow or orange to dark yellow or brown.The colour of the adults often depends

• Tomato leafminer

  die off completely. Mining by the caterpillar causes malformations. Damage to fruit allows fungal diseases to enter, leading to rotting fruit before or after [...] leaf miner ( Tuta absoluta ) are cylindrical. Their colour varies from creamy white to bright yellow, darkening in the embryonic phase and becoming almost [...] first-instar larvae are whitish to yellowish after emerging. They mine inside the leaf, stem or fruit. In the second to fourth instars they become greenish

• Southern European marshland pyralid

  infection by the fungus Botrytis cinerea . In gerbera, the flower buds may also be eaten. It has even been known for the caterpillars to inflict damage to the [...] considerably according to the crop: in begonia and kalanchoë a relatively small population can cause severe damage, whereas roses appear to tolerate larger numbers [...] formed by the head and forewings. Moths mainly fly at night, but can sometimes be seen in the daytime. Eggs are laid singly or in groups of 5 to 10 eggs