Cactus mealybug

mealybug usually infests stems but can occasionally be found on crowns, roots. and flowers. Depending on the host plant species, infestations with cactus mealybug [...] was first described in England but its origin is not clear. It is now found on many greenhouse-grown succulents around the world as it was probably distributed [...] They are actively mobile and known as ‘crawlers’. From the second instar on, they are covered with white waxy exudate and become more sedentary and only

Diamond back moth

damaged plants appear stunted and will, in most cases, die. On rapeseed, larvae also feed on flower buds, flowers and young seed pods, causing loss of pods [...] small groups of two or ten eggs on both the upper and lower surface of leaves, preferentially in depressions, and rarely on stems or petioles. There are four [...] surface feeder. They feed from the lower leaf surface, leaving the wax layer on the upper surface intact, thereby creating translucent windows. In cases of

Olive scale

causing build-up of sticky deposits on nearby surfaces. The honeydew may attract attendant ants and sooty moulds grow on the sugary deposits. Removal of large [...] two transverse crests and one median ridge that together form the letter H. On citrus, early stages might be yellow but they become darker later. First-instar [...] until they hatch. The emerging crawlers settle mostly along the main veins on the lower sides of mature leaves. Many young females migrate to twigs and

Damping-off

fall off. The side roots rot and very little of the root system survives. On the border between air and soil or substrate the plant turns brown. A typical [...] where the side roots are formed or through other similarly damaged spots. On the infected plant, new sporangia with zoospores are formed, that allow the [...] not harm plants. How to prevent Damping-off Use resistant cultivars or graft on tolerant cultivars Use clean planting material Ensure regular growth Avoid

Cutworms

first but rapidly turn darker. They are laid separately or in batches on the ground, or on the plant close to ground level. The larvae are yellowish when hatching [...] and the turnip moth Agrotis segetum . The larvae of these moths usually feed on roots and plant parts close to the ground, thereby often cutting the stems [...] symptoms Early instar cutworm larvae can create 'shotholes' while feeding on tender leaves of seedlings. Third to seventh instars become negatively phototaxic

Silver-Y moth

symptoms The larvae feed on leaves, causing typical caterpillar damage. Feeding damage includes feeding on the leaf epidermis and on the petiole, skeletonized [...] brassicas, from August onward. The silver-Y moth ( Autographa gamma ) feeds on plants of 14 families and is sometimes also encountered in greenhouse crops [...] their wings folded roof-like above the body. The female lays up to 2,000 eggs on the underside of the leaves of their host plant, usually separately but sometimes

Hemp russet mite

freely (vagrant) on hemp/cannabis plants. Aculops cannabicola is host specific to hemp/cannabis ( Cannabis sativa ). It cannot survive on other plants. Damage [...] mite develops on the stems and petioles of the hemp plant and can cause stunting. When populations are large, the mites can also be found on the underside

Oleander aphid

the families Apocynaceae and Asclepiadaceae. It is commonly found feeding on oleander and milkweeds ( Asclepias sp.). The oleander aphid is cosmopolitan [...] oleander. Damage symptoms The colonies of bright yellow aphids can easily be seen on the shoots of the host plants. The damage caused by the aphid colonies is [...] of sticky honeydew produced and the resulting black sooty mould that grows on the honeydew. Growing tips can be deformed. Repeated heavy infestation throughout

Southern European marshland pyralid

decaying organic material on the ground or substrate. They feed on detritus as well as life materials. Young larvae feed on the leaves and flowers before [...] eggs, overlapping in a tile-like fashion on both the upper and lower surface of leaves close to the veins, or low on the stem or stalk close to the ground [...] European pepper moth (Duponchelia fovealis) is a polyphagous species feeding on a wide range of hosts from 38 plant families. They include ornamental crop

Bacterial soft rot, bacterial stem rot

Above or below the hollow stem the vascular tissue keeps its normal colour. On the fruits, lesions first are small and sunken, water-soaked and light to [...] reach epidemic population densities. It can survive as epiphytic bacteria on various plants or in the soil in low densities. It has also been found in