San Jose Scale (Quadraspidiotus perniciosus) of Apple
It is a notorious pest of apple which is named as San Jose Scale because the pest first attracted the attention of growers at San Jose in California during 1873. It damages all parts of the apple plant above the ground level by sucking cell sap. Insects form dense colonies on the plant parts and reddish or pinkish rings appear on the fruits and Twigs. Infested twigs may die within few months.The parasitoids Encarsia perniciosi, Aphiitis sp., Chiloneurus sp. and predators Chilocrus bijugas, Coccinella septumpunctata are used to destroy the San Jose scale colonies. The insect is also controlled by spraying 2-3% mineral oil or 4-5% diesel oil emulsion on dormant trees during winter. Single spray of 0.02% chloropyriphos 20 EC or 0.03% dimethoate 30EC at first crawler emergence stage during May is also recommended to control San Jose Scale.
Woolly aphid (Eriosoma lanigerum) of Apple
It is a serious pest in apple growing areas. The aphid is purplish in colour and covered with white cottony masses. It is active during March to December and multiplies very fast. The nursery plants and young orchards are more prone to damage by woolly aphids. It feeds on sap of branches, twigs and roots of plants. Gall formation takes place at infested sites due to excessive cell division. The affected plants lose their vigour and give poor yield. The infested planting materials should not be used to prevent the aphid. The parasitoids Aphelinus mali and predators Coccinella septumpunctata and Hippodamia variegare may be used to control the woolly aphids. The spraying of 0.03% dimethoate 30EC or monocrotophos 36SL once during March-April and second during June-July protects the aerial parts of the plant. The soil application of 10-30g phorate 10G or 30-50g carbofuran 3G per plant at 5 cm depth is advised to control the insect in the root zone of the plants. The woolly aphid resistance root stock Merton- 793 may be used for propagation.
European Red Mite of Apple
The mite is found in all apple growing areas of India. In addition to apples it also attacks pear, peach, apricot, plum and almond. Mites suck cell sap from tender parts and leaves of the plant resulting in premature leaves fall. It may cause up to 30% economic loss to the apple orchards. The mites’ population may be controlled by predators Typhlodromous sp, Amblyseius sp. Zetzellia sp. and Crysoperla sp. Red mites can also be controlled effectively by spraying 0.05% lindane 20EC with 2% oil at pink bud stage and later on whenever the mite population exceeds 15-20 mites /leaf.
Disease Management in Apple (link)
