Category : Insects
Aphids (Green apple aphid, Woolly apple aphid)
apple aphid (Aphis pomi) overwintering eggs
Woolly aphid damage
Infestation of apple tree with woolly apple aphid (Eriosoma lanigerum)
Green apple aphid colony on crab apple
apple aphid (Aphis pomi) infestation
Woolly aphid infestation
Perennial canker on an apple tree, caused by woolly aphids (Eriosoma lanigerum).
Woolly apple aphid colony
Woolly apple aphid damage
Woolly apple aphid colony
Cankerous tumours on apple shoot caused by colonies of Eriosoma lanigerum.
Woolly apple aphid infestation on crab apple
Small soft bodied insects on underside of leaves and/or stems of plant; usually green or yellow in color, woolly apple aphids are covered in masses of white, wool-like material; green apple aphids are dark green when they forst hatch and change to yellow-green with darker green spots as they mature; if aphid infestation is heavy it may cause leaves to yellow and/or distorted, necrotic spots on leaves and/or stunted shoots; aphids secrete a sticky, sugary substance called honeydew which encourages the growth of sooty mold on the plants.
If aphid population is limited to just a few leaves or shoots then the infestation can be pruned out to provide control; check transplants for aphids before planting; use tolerant varieties if available; reflective mulches such as silver colored plastic can deter aphids from feeding on plants; sturdy plants can be sprayed with a strong jet of water to knock aphids from leaves; insecticides are generally only required to treat aphids if the infestation is very high - plants generally tolerate low and medium level infestation; insecticidal soaps or oils such as neem or canola oil are usually the best method of control; always check the labels of the products for specific usage guidelines prior to use.
apple cut open to show damage by the apple maggot (Rhagoleti pomonella).
External symptoms of injury on apple.
Apple maggot (Rhagoletis pomonella) damage to apple
Apple maggot damage
Adults captured on Pherocon AM trap
External appearance of apples damaged by the apple maggot (Rhagoleti pomonella).
Paradise apple injured by apple maggot (Rhagoletis pomonella).
Female adult insect
Apple tree with a yellow sticky trap for apple maggots (Rhagoleti pomonella).
Symptoms of apple maggot on fruits
Misshapen, pitted and sunken areas on fruit surface; browning and rotting of apple flesh.
Use red spherical sticky traps to trap adults, place one trap for every 100 apple fruits; bag apples by tying or stapling polythene bags around fruit to prevent adults laying eggs - cut corners from bags to ensure air supply to fruit; spray fruit with insecticide prior to eggs being laid.
Tunneling made by exiting codling moth larva
Damage caused to an apple fruit by the codling moth Cydia pomonella in the field.
Moth pupa in apple fruit
Codling Moth Larva in Apple
Damage to apple fruit by moth larvae
Codling moth larva in apple fruit
Holes and burrows in fruit; holes may be blocked with crumbly brown frass (insect excrement); wounds may be shallow or may be deep burrows extending to the fruit’s core; adult insect is a dark brown moth; larvae are pink with a brown head and may be up to 1.3 cm (0.5 in) long.
Proper pruning methods help to open out tree canopy to ensure treatments penetrate interior of the tree and reach larvae; removal of any wild hosts or trees in abandoned orchards helps remove reservoirs of insect; organically acceptable control methods include application of Entrust and kaolin clay; small scale growers and home gardeners can remove infested fruit by hand before larvae leaves fruit to reduce insect population; successful reduction of insect population in large scale orchards is usually achieved by mating disruption by releasing pheromones over successive years.
Leafhoppers (White apple leafhopper, Rose leafhopper)
white apple leafhopper Nymphal skin
Characteristic white stippling on crab apple leaf caused by leafhoppers
White apple leafhopper adult
White apple leafhopper nymph on underside of leaf
White stippling on foliage; may be a reduction in fruit size; black specks of frass on fruit; sticky exudate on fruit and leaves caused by excretion of honeydew by insect.
Control of leafhoppers is becoming problematic as they are developing resistance to organophosphate insecticides; sprays of appropriate insecticides are most effective at controlling the insect before the adults emerge; monitor trees for appearance of nymphs.
Leafrollers (Omnivorous leafroller, Redbanded leafroller, etc)
omnivorous leafroller (Platynota stultana) larva
Redbanded leafroller on apple leaf
Leaves of plant rolled and tied together with silk webbing; feeding damage to rolled leaves; defoliation of plant; silk webbing may also be present on fruits and fruits may have substantial scarring from feeding damage; larvae wriggle vigorously when disturbed and may drop from plant on a silken thread.
Monitor plants regularly for signs of infestation; remove weeds from plant bases as they can act as hosts for leafrollers; Bacillus thuringiensis or Entrust SC may be applied to control insects on organically grown plants; apply sprays carefully to ensure that treatment reaches inside rolled leaves.
Roundheaded apple tree borer
Roundheaded apple tree borer (Saperda candida) adult
Borer holes at base of tree
The presence of bore holes at the base of tree which are covered by pigtail-shaped frass and/or darkened areas in the bark due to sap flow are the proof of insect infestation. The young may kill by one or two larvae infestation. The older trees show drying and break off near the base.
Use of trunk wraps to avoid insect attack. Removing and killing of larvae from the tunnel if possible. Application of suitable insecticide.
Adult red shouldered stink bug
Dark colored pinpricks on fruit; depressed dimples on fruit surface with white, pithy area underneath; stink bugs often carry pathogens in their mouthparts which can cause secondary infections and decay of fruit; adult insect is shield-shaped and brown or green in color; may have pink, red or yellow markings; eggs are drum shaped and laid in clusters on the leaves; larvae resemble the adults but are smaller; insect frass may be visible on the fruit is small, brown teardropped shaped deposits
Remove weeds around crop which may act as overwintering sites for stink bugs and practice good weed management throughout the year; organically accepted control methods include the use of insecticidal soaps, kaolin clay and preservation of natural enemies
Category : Mites
Characteristic stippled leaf caused by spider mites
Leaves stippled with yellow; leaves may appear bronzed; webbing covering leaves; mites may be visible as tiny moving dots on the webs or underside of leaves, best viewed using a hand lens; usually not spotted until there are visible symptoms on the plant; leaves turn yellow and may drop from plant
In the home garden, spraying plants with a strong jet of water can help reduce buildup of spider mite populations; if mites become problematic apply insecticidal soap to plants; certain chemical insecticides may actually increase mite populations by killing off natural enemies and promoting mite reproduction