Dr. Phyto

apple

Malus domestica

Diseases & pests on this plant

• apple scabVenturia inaequalis

  Olive-green to black velvety spots on leaves, similar dark sunken scab on fruit causing cracks, premature leaf and fruit drop, weakened tree over years.

• codling mothCydia pomonella

  Small entry hole on the fruit skin (often near the calyx) with reddish frass, brown tunnels through the flesh to the seed cavity, premature fruit drop, larvae visible inside cut fruit.

• Brown marmorated stink bugHalyomorpha halys

  Shield-shaped brown bug ~17 mm with alternating light and dark bands on the antennae and abdomen edge; feeding causes corky, dimpled, cat-faced distortion on tree fruit, cloudy or necrotic spots on peppers and tomatoes, and shrivelled pods on soybean. Adults gather on and enter buildings to overwinter.

• apple powdery mildewPodosphaera leucotricha

  White powdery coating on new shoots + young leaves, distorted curled young foliage, infected shoots whitened from tip, russeting + scarring of young fruit.

• green apple aphidAphis pomi

  Dense clusters of green aphids on shoot tips and leaf undersides, curling and yellowing of new leaves, sticky honeydew, sooty mould, slow shoot growth.

• apple maggotRhagoletis pomonellaEU-notifiable quarantine organism

  The female punctures the apple skin to lay eggs, leaving tiny dimples; the maggots tunnel winding brown trails through the flesh, which becomes pitted, distorted and "bumpy", and rots; the fly has a dark F- or zigzag-banded wing pattern. Infested apples drop early. Not present in the EU.

• Light brown apple mothEpiphyas postvittana

  Leafroller caterpillars web leaves together and to fruit with silk, feeding within the shelter; surface chewing and shallow 'scribble' scarring on fruit near the calyx or where leaves touch. Small light-brown moths rest with a bell-shaped wing profile.

• Queensland fruit flyBactrocera tryoni

  Small 'sting' punctures on ripening fruit, often with a weeping or dimpled spot; maggots (cream-coloured larvae) tunnel the flesh causing internal rot and premature fruit drop. Adults are wasp-like, reddish-brown flies with clear wings seen resting on foliage and fruit.

• Japanese beetlePopillia japonicaEU-notifiable quarantine organism

  Adults are bright metallic green with coppery wing-cases and small white tufts of hair along the sides of the abdomen; they feed in groups in sunshine, skeletonising leaves between the veins (a lacy look) and chewing flowers and fruit of a huge range of plants (rose, grape, lime, fruit, soft fruit); the white C-shaped grubs eat grass roots, causing brown patches of lawn that lift like a carpet.

• woolly apple aphidEriosoma lanigerum

  Cottony-white waxy colonies on woody branches + trunk wounds, distinctive purplish-red galls around colony sites, secondary swellings on rootstock.

• apple blotchMarssonina coronaria

  Dark-brown angular leaf spots merging into large blotches, intense yellowing + premature leaf drop from June onward, completely defoliated trees by August in epidemic years.

• honey fungus (Armillaria root rot)Armillaria mellea

  Plants decline, leaf out poorly, then whole branches or the whole shrub/tree dies — often suddenly in summer; under the bark at the base and on the roots there is a sheet of white fungal growth that smells strongly of mushroom; flat black "bootlace" rhizomorphs run through the soil; honey-coloured toadstools may appear in clusters at the base in autumn.

• fire blightErwinia amylovoraEU-notifiable quarantine organism

  Sudden blossom wilt with blackened shoots curling into a shepherd's crook, amber bacterial ooze on bark in warm weather, scorched-looking dead leaves still clinging, rapid spread in spring.

• European pear-juniper rustGymnosporangium tremelloides

  Bright orange spots on upper apple/pear leaves with orange tube-like aecia on undersides, gelatinous orange galls on juniper branches in spring, leaf drop in heavy attacks.