Urban Orchards : Common Pests of the Urban Orchards and their Organic Controls

Common Pests of the Urban Orchard (in the Northeast) and Their Organic Controls

Aphids
Affects: All fruit plants, there are many species of aphid, but each is plant specific.
Description:: Adult - 1/8-1/32”, pear-shaped, light green, dark green, or black, wingless. Some show white cottony coating (woolly apple aphids).; Larva - Smaller version of adult.
Damage: Adults/larvae suck sap causing distortions to leaves/buds/flowers/fruit, leaf curl, leaf and flower drop. Aphids secrete honeydew causing sooty mold on leaves and fruit.
Controls:: Eggs overwinter in bark and on twigs. When trees are dormant, destroy eggs by spraying with dormant fruit tree oil.; Spray foliage with soap/water solution at high pressure.; Woolly apple aphids feed on roots and trunk/branch wounds. Cultivate soil around the tree to a depth of 1-3”, and paint trunk/bark wounds with wound dressing.; Release and encourage lady bugs, lacewings, syrphid flies, and/or ant lions.; Use horticultural oil at bud break. This should not be necessary if no general pesticides have been used.

Apple Curculio: Similar to Plum Curculio, but a seperate species. See Plum Curculio.

Apple Maggot (also known as Cherry Fruit Fly)
Affects: Tree fruit, specifically apples, cherries, and plums.
Description:: Adult - Black fruit fly, ¼”, with transparent wings with black crossbands.; Larva - Yellowish white maggot, 1/3”.
Damage: Adults lays eggs under skin of fruit, larvae tunnel throughout flesh, causing fruit to rot and drop prematurely.
Controls:: Pick up and destroy dropped fruit daily, and twice per month after September 1.; Plant late season apples.; Hang maggot traps 4 weeks after petal fall.; Release and encourage ground beetles and rove beetles.

Borers
Affects: Tree fruit peach, apple, plum, cherry in some areas. Small fruit: raspberry, grape

Flatheaded Appletree Borer
Description:: Adult - flat, dark-bronze beetle, ½”.
Larva - white grub, 1¼”, legless, flat wedge-shaped head.
Damage: Adults eat leaves, larvae eat cambium layer, tunnel extensively under bark, and form galleries filled with castings. Damaged bark exudes gummy sap. Infested trees can die.
Controls:: Avoid injury to bark, and remove damaged limbs immediately.; Protect trunks of young trees. Paint lower trunk with white latex paint dilution (equal amounts paint and water), and wrap the lower trunk with paper or burlap.; Destroy borers - cut young borers from tree with knife, removing as little wood as possible, and paint over wound with the latex paint dilution above. For older borers probe their tunnel with hooked wire

Grape Vine Borer (also known as Grape Vine Girdler)
Description:: Adult - black beetle, 1/3".; Larva - small, tawny grub.
Damage: Adult cuts young shoot 10” below tip and lays eggs in shoot 6” below cut (double ring of tiny punctures). Larvae tunnel down cane to eat emerging shoots.
Controls: Upon discovery of severed shoots, cut cane 4-6” below puncture holes and destroy.

Greater Peach Tree Borer
Description:: Adult - blue-black moth, 1¼”, with yellow-orange body bands, and translucent wings. Attracted to injured/diseased wood. Resembles a wasp.; Larva - white caterpillar, 1/8-1”, with a brown head.
Damage: During early June larvae eat the cambium layer, burrow into base of main trunk (often into graft union) and main roots, and girdle the tree, often killing young trees. Entrance holes exude a gummy sap.
Controls:: In late summer/fall, inspect trees for damage from above ground to 3” below ground.; Repel borers by encircling tree with a mound (4-6” wide) of tobacco dust. Destroy pupating larvae. In spring and fall, cultivate soil around base of tree.; Impale tunneling larva by inserting a flexible wire in hole. Release/encourage parasitic wasps, inject nematodes.

Peach Twig Borer
Affects: Peach.
Description:: Adult - gray moth, 3/8” wingspan, black markings.; Larva - brown caterpillar, ½”.
Damage: Damage is cause in a two-generation cycle. First generation of larvae tunnels into twigs, causing them to wilt and exude gummy sap. Second generation tunnels into and eats fruit, usually near stem.
Controls:: Keep trees healthy, as borers prefer weak trees.; Destroy infested prunings. Cut wilted twigs just below entry hole.; Impale larvae in larger branches by inserting flexible wire in hole.

Raspberry Cane Borer
Description:: Adult - black beetle, ½", yellow-orange thorax.; Larva - small, tawny grub.
Damage: Adult lays eggs in canes (double ring of tiny puncture holes) 6” below tip, cane tip withers.
Controls: Destroy larvae. Upon discovery of withered shoot, cut cane 4" below puncture holes and destroy.

Raspberry Crown Borer
Description:: Adult - clear-winged moth, 1”, resembles yellow jacket.; Larva - tawny grub, 1/2”. 2-year larval stage.
Damage: Larvae cause entire plants to wither and die. Year 1 - feeds on buds and new canes at base of plant. Year 2 - feeds on crown of plant.
Controls: Remove damaged canes, locate and destroy grubs.

Roundheaded Appletree Borer
Description:: Adult - yellow or reddish brown beetle, ¾”, with white stripes.; Larva - creamy white grub, 1½”, dark head.
Damage: Larvae bore into trunk at ground level (often into graft union), girdling the tree or penetrating into heartwood.
Controls:: Impale tunneling larva by inserting flexible wire into the hole.; Inject parasitic nematodes into the hole.; Remove nearby wild host trees.

Shothole Borer
Description:: Adult - brown-black beetle, 1/10”, red-tipped wing covers.; Larva - white grub, ½”, reddish-brown head.
Damage: Adults/larvae tunnel extensively under bark (form galleries), and eat/destroy cambium layer. Adults bore multiple bullet-like holes in bark upon emergence, and again when they lay eggs. Damaged bark exudes a gummy sap.
Controls:: Protect trees by painting the lower trunk with white latex paint dilution (equal amounts paint and water).; Larvae overwinter in wood, so destroy infested branches during winter.; Impale tunneling larva by inserting flexible wire into the hole.

Codling Moth
Affects: TApple, pear, occasionally cherry.
Description:: Adult - grayish brown moth, 1/2", wings mottled gray with copper tips.; Larva - whitish pink worm, 1", brown head.
Damage: Most destructive pest of apple trees. Larvae feed around core of fruit, causing "wormy" apple; fruit drops prematurely; light-brown castings (frass) surrounds exit hole at calyx (blossom end).
Controls:: Larvae overwinter in cocoons under loose bark, in crevices - remove debris (including mulch) from around base of tree; during fall/winter, scrap off dead bark, being careful not to injure living wood (best done during damp weather when rough bark comes off more easily).; Trap larvae by creating a false shelter by banding tree trunks and branches with 6” strips of burlap or cardboard. In fall, check strips for larvae and destroy.; Hang pheromone traps.; Release/encourage predatory wasps (trichogramma). Encourage birds that feed on hibernating larvae (downy woodpecker, nuthatch, chicadee).

Cutworm
Affects: All small fruit, especially grapes.
Description:: Adult - brown-gray moth, 1”.; Larva - gray-dull brown caterpillar, 1-2”, shiny head, nocturnal feeder, active mid-May through June.
Controls:: Protect plants by placing collars (metal/cardboard/plastic) around base of young plants, to 3" below soil line.; Cultivate soil around plants and crush larvae, mid-May through June.; Release parasitic nematodes.

Fruit Worms
Affects: All tee fruit except peach.
Description:: Adult - bluish gray moth.; Larva - green or brown caterpillar (like a climbing cutworm), 1¼”, white/yellow stripe on each side. Active until May-mid June, then pupate/hibernate 1-3” underground until September/spring
Damage: Larvae eat leaves and chew large holes in fruit.
Controls: Hand pick larvae and crush, destroy pupating larvae by cultivating soil around tree to depth of 1-4”.

Fruit tree Leafroller
Affects:: Tree fruit: apple, pear, peach, plum, apricot, and cherry.; Small fruit: bush fruit, brambles.
Description:: Adult - golden brown moth, 1/2”, light markings on wings.; Larva - green caterpillar, 1”, brown head, usually found in web encasing curled leaf tip.
Damage: Larvae curl and encase leaves in webbing; eat leaves, buds, and immature fruit.
Controls:: Crush caterpillars in webbing on leaves.; Release/encourage parasitic wasps (trichogramma). Encourage birds and toads, which eat caterpillars.

Grape Berry Moth
Affects: Grapes.
Description:: Adult - gray moth, dark mid-band.; Larvae - two larval stages per season, both are small brown caterpillars.
Damage: Larval stage 1 - feeds on fruit stems. Larval stage 2 - feeds on berries, ruining an entire cluster.
Controls:: Destroy pupating stage l larvae by cultivating the soil around the base of the vine in late fall and early spring.; Disrupt mating with pheromones.

Japanese Beetle
Affects: Raspberry, grape.
Description:: Adult - chunky, metallic blue-green beetle, ½”, bronze wing covers.; Larva - off-white grub, ¾”, brown head, found in soil.
Damage: Adults eat flowers and skeletonize leaves, completely defoliating plant. Larvae eat roots.
Controls:: Destroy adults by hand picking or shaking from the plant onto a dropcloth. Crush or drown in soapy water.; Crush larvae when found in soil.

Mites (note that these 8-legged animals are not technically insects)
Affects: Many species, each of which is plant specific.

Rust Mite
Description:: Adult - pinpoint size, 1/125”, pale yellow, spider-like.; Larva - smaller version of adult. Active with onset of growing season, many generations per season.
Damage: Adults/larvae burrow into undersides of leaves and suck fluids, causing brown-red blisters (1/8” wide) on leaves and skin of fruit. The mites overwinter in bud scales causing weak flowers and emaciated fruit.
: Destroy overwintering adults/eggs - spray dormant oil with lime-sulfur on dormant trees, especially buds.; Spray foliage with soap-water solution under high pressure.; Spray foliage with sulfur fungicide.

Spider Mite
Description:: Adult - 1/50”, reddish, pale green, or yellow, spider-like.
Larva - smaller version of adult. Active with onset of growing season, many generations per season.
Damage: Adults/larvae suck fluids from undersides of leaves. Early damage is seen in yellow-specked areas on leaves. Later damage is seen in yellowed-bronzed leaves, possibly covered in webbing growing tips, possible leaf drop and stunted fruit.
Controls:: Adults/eggs overwinter in bark crevices and garden debris - when tree is dormant spray dormant fruit tree oil; keep area around tree clear of debris (including mulch).; Wash foliage with soap-water solution, sprayed under high pressure.; Release and encourage lady bugs, predatory mites (Metaseiulous occidentalis), and predatory thrips.

Oriental Fruit Moth
Affects: Peach, occasionally cherry and plum.
Description:: Adult - dark gray moth, ½”, mottled wings.; Larva - pinkish-gray worm, ½”, brown head.
Damage: Several generations of larvae per season. Spring generation bores into twig tips, causing them to wilt and die. Mid-summer generation bores into immature fruit leaving gummy mess on fruit. Late-summer generation enters stem-end of maturing fruit and bore into pit.
Controls:: Plant early season peaches and apricots.; Destroy overwintering larvae - cultivate soil around trees to depth of l-4”, l-3 weeks before blooming.; Release/encourage parasitic wasps and flies.; Disrupt mating with pheromone patches.

Pear Psylla
Affects: Pear, quince.
Description:: Adult - reddish brown “jumping louse”, 1/8”, long transparent wings sloping over back.; Larva - yellowish, flattened, wingless, covered with honeydew. Becomes greenish or brownish black as it grows.
Damage: Larvae suck sap, weakening tree; fruit skin becomes scarred, blackened with sooty mold that grows on honeydew; leaves yellow from toxic saliva. Spreads pear decline virus.
Controls:: Adults overwinter in leaves, mulch, and dead ark on trunk and large branches - keep area around tree clear of debris (including mulch). During fall/winter, scrape off dead bark, and be careful not to injure living wood (best done during damp weather when rough bark comes off more easily), burn scrapings when psyllids are abundant.; Destroy newly hatched nymphs by spraying dormant fruit tree oil in early spring when buds begin to swell.; Release and encourage natural predators.

Plum Curculio
Affects: Plum, apple, peach, apricot, cherry, occasionally pear.
Description:: Adult - hard-shelled, snout-nosed beetle, 1/5”, grayish brown or mottled black, 4 humps on back.; Larva - whitish-yellow, plump grub, 1/3”, brown head.
Damage: Adults feed on fruit in spring, and make crescent-shaped cuts where they lay eggs. Larvae tunnel in fruit.
Controls:: Destroy adults by tapping branches to knock beetles onto a cloth and destroying them (during the week after petal drop).; Pick up and destroy dropped fruit.; Destroy larvae/pupae by cultivating soil around trees during late spring/early summer.; Adults overwinter in leaves and mulch, so remove debris (including mulch) from around base of tree.; Adults do damage in deep shade, so prune your trees to admit sun.; High winter mortality. Encourage birds, predatory insects (a wasp attacks the larvae in fruit, and parasites attack eggs), and fungal diseases (attack adults and larva).

Rose Chafer
Affects: Tree fruit - apple, pear, peach, plum, apricot, and cherry. Small fruit - many, esp. grape.
Description:: Adult - reddish brown beetle, 1/2", black underbody, long hairy legs.; Larva - small white grub, found in soil.
Damage: Adults skeletonize leaves and eat buds/flowers/fruit.
Controls:: Destroy adults by hand picking and crushing them, or drown them in soapy water.; Destroy larvae/pupae by cultivating soil mound plants, from May to early June.

Scales
Affects: Different species are specific to different fruit, but there are species that affect most fruit types.

Armored Scale* (Oystershell, San Jose, Lecanium)
Description:: Adult - immobile, light tan to gray, circular/oval, 1/10”, secretes waxy covering in oystershell/circular patten.; Larva - crawler, moves to new feeding sites (May), settles, and molts to adult form.
Damage: Adults/larvae suck sap from twigs, leaves, and fruit, and inject toxic saliva. Scales also secrete honeydew causing sooty mold on leaves and fruit.
Controls:: Larvae/eggs overwinter in bark when tree is dormant. Destroy the eggs by spraying dormant fruit tree oil, and destroy larvae and eggs by spraying superior oil.; Scrape adults from bark/twigs and crush.; Release and encourage ladybugs (Chilocorus nigritus), and predatory wasps and mites.
*Waxy covering makes pesticides ineffective

Soft Scale
Description:: Adult - same as Armored Scale but no waxy covering. Minute, yellow-winged, fly-like.; Larva - mobile, crawler resembling tiny mealybugs.
Damage: Adults/larvae suck sap from twigs and leaves, and secrete honeydew causing sooty mold on leaves and fruit. The leaves eventually drop, and the plant dies.
Controls:: Larvae/eggs overwinter in bark when tree is dormant. Destroy eggs by spraying dormant fruit tree oil, and destroy larvae/eggs by spraying superior oil.; Prune and destroy infested twigs.; Scrape adults from twigs with a fingernail. Wash from leaves with soft cloth and soapy water (rinse plant well).; Release/encourage lady bugs (Chilocorus nigritus), soldier beetles (Cantharus fusca), parasitic wasps (Metaphycus helvolus for soft brown scale), and predatory mites.

Tarnished Plant Bug
Affects: Tree fruit - peach, plum, cherry, apple and pear. Small fruit - strawberry, raspberry, grape.
Description:: Adult - light green to brown shield-shaped bug, 1/4”, with black spots or reddish stripes, mottled wings. Lay eggs in stems of weeds and herbaceous plants; Larva - similar to adults, except smaller and wingless.
Damage: Adults/larvae suck sap, and inject toxins into buds, shoots, and fruits, causing shoot and fruit distortion (sunken areas on fruit called “catfacing”), bud drop, and shoot wilting, stunting, or dieback.
Controls:: Keep area around base of tree clear of weeds and herbaceous plants.; Destroy fruit that has been infested, prune away damaged shoots.; Release and encourage bigeyed bugs (plant subterranean clover and berseem), damsel bugs, and pirate bugs.

Tent Caterpillar (also known as Webworm)
Affects: Apple, (wild) cherry.
Description:: Adult - yellowish tan to brown moth, 1”, with 2 diagonal wing stripes.; Larva - hairy caterpillar, 1-2”, with black and white stripes or dots on back, brown/blue/red marks along sides; web tents in crotches of trees.; Eggs - brown/black mass, hard, shiny, encircling twig.
Damage: Larvae eat leaves, and can completely defoliate plant.
Controls:: Remove and destroy egg masses.; Remove tents by winding onto barbed stick and destroying them.; Hand pick and crush caterpillars (do not destroy caterpillars with white eggs/cocoons on them - they are being parasitized) prune and burn badly infested branches.; Release and encourage spined soldier bugs, parasitic flies and wasps.

For more information on obtaining insect traps, see our list of resources and references.