Asian citrus psyllid

young stems and on leaves of all developmental stages. Nymphs feed on young leaves and stems, continuously secreting copious amounts of honeydew and a thread-like [...] distributed in southern Asia and the disease is responsible for the destruction of several citrus industries in Asia and Africa. In North America, it has [...] huanglongbing (HLB). Nymphs and adults of the psyllid take the bacteria into their bodies by feeding on bacteria-infected plants and then disease is spread

Grape mealy bug

stem, on leaves and berries. Mealy bugs are pinkish and covered with white mealy wax. Female lays 300-500 eggs in loose cottony ovisac and eggs are orange [...] Damage symptoms Adults and nymphs suck the sap from the leaves, shoots, flowers and grape bunches. Malformation of leaves and shoot tips due to infestation [...] honey dew, sooty mould and dead mealy bugs on grape berries. Infected bunches are not suitable for making raisins. Life cycle and appearance Mealy bugs

Tobacco whitefly

high level of resistance to many insecticides and its propensity for the transmission of viruses. Life cycle and appearance of Tobacco whitefly The tobacco [...] egg, first, second, third and fourth larval stage (often referred to as ‘pupa’ although strictly spoken this is not true) and adult. The larvae are found [...] develops into a yellow, almost circular so called pupa, in which the red eyes and white wings of the adult are already clearly visible. These pupae are found on

Crazy roots, hairy roots, crown gall

stems, which are first white and later turn brown. Only Rhizobium radiobacter causes galls and tumours on underground plant parts and on the crown. Furthermore [...] break open, releasing many bacteria. These are dispersed by rain and wind and by humans and tools. Until now, no bacteria have been isolated from crazy roots [...] roots, hairy roots and crown gall. Damage symptoms The four pathogenic Rhizobium species cause different symptoms, like galls, tumours and excessive root growth

Aphids

the crop and its fruit sticky. Black fungal moulds (such as Cladosporium spp. and Capnodium spp.) grow on this honeydew, contaminating fruit and ornamental [...] are among the most harmful pests in greenhouse and field crops, causing plant stress, virus transmission and yield loss. Effective aphid control is essential [...] subsp. persicae ( green peach aphid ) and Myzus persicae subsp. nicotianae ( tobacco aphid ) on various vegetable and ornamental crops. Aphis gossypii ( cotton

American serpentine leaf miner

premature leaf-fall and cosmetic damage. In tropical and subtropical areas this can lead to burning in fruit such as tomato and melon. Loss of leaves [...] stages: egg, three larval instars, a pupal instar and the adult fly. Adult leaf miners are small yellow and black coloured flies , at most only several millimetres [...] highly polyphagous and thus lives on many host plants such as chrysanthemum, gerbera, gypsophila, celery, sweet pepper, pea, bean and potato. In greenhouses

Angular leaf spot

happens both passively and actively. Infection and disease development are favoured by temperatures around 20 °C during the day and cold nights, in combination [...] underside of the leaf. This exudate changes to a white film when it dries. Lesions may merge as they grow and later also become visible on the upper side of [...] fragariae infection. Life cycle and appearance of Angular leaf spot Xanthomonas fragariae overwinters in plants and dead leaves, that become the primary

Grape downy mildew

appearing as white, cottony growth. Shoot tips and central axis of flower clusters become distorted into a curl or corkscrew. Inflorescences and young berries [...] spores. Early infected clusters can turn brown, dry, and fall off; later infections cause discoloration and shriveling without sporulation (brown rot phase) [...] also survive as mycelium in grape buds and canes. In spring, oospores germinate when temperatures reach 10°C and soils are wet, forming macrosporangia that

Broad mite

the surface and are rather large (about 0.07 mm) compared with the subsequent, active stages. They are transparent and speckled with white dots. The larva [...] but is slightly smaller and has only three pairs of legs. The emerging adult mite is roughly 0.2 mm long, oval and broad, and pale yellow or yellow-green [...] peppers, but also aubergine, tomato and cucumber. Additionally, many ornamental crops such as azalea, begonia, gerbera and cyclamen are also affected. Outside

Guava

About Originally from Mexico, Central and South America, this common tropical fruit is cultivated in many tropical and subtropical regions. A vivid yellow [...] family (Myrtaceae) – a smallish tree. The pulp varies from off-white to bright pink, and is between 4 to 12 cm in length. The taste ranges from tart to