Overview

in the spring and early summer, both aphid species infest young trees, water sprouts, and vigorous terminals on apple, pear, and quince. Unlike rosy apple aphids, which spend part of their life cycle on plantain, both green apple aphid and spirea aphid remain on apple year-round.

Aphid nymphs and adults suck sap from apple leaves, favoring rapidly growing terminal and water sprout foliage. Leaf curling indicates aphid presence, but causes little or no damage. Aphids excrete large amounts of honeydew which may collect on fruit and foliage. Black sooty-mold fungus can develop on honeydew, discoloring fruit.

Biology

• Apple aphid and spirea aphid overwinter as black, shiny eggs on the rough areas (leaf and pruning scars, terminals, and spurs) of the bark of the previous season's growth. Eggs hatch in spring and nymphs (all of which are females, called "stem mothers") mature while feeding on developing foliage.
• Aphid adults are a uniform yellowish-green to green color with black cornicles at the end of the abdomen.
• The "stem mothers" feed, mature, and produce another generation of live nymphs, all of which are females. This type of reproduction without mating is called parthenogenesis. Eventually, winged aphids ("alates") appear, and for the duration of the summer, the population consists of both winged and wingless parthenogenetic females that continue to produce live nymphs.
• In late summer, the winged aphids disperse to different apple trees or other host plants and produce nymphs that develop into true sexual forms. After mating with males, females lay overwintering eggs that hatch the following spring. the cycle then repeats itself.
• Apple aphids and spirea aphids are similar in appearance, but spirea aphids may remain active on apple trees later into the summer.
• A different aphid, the apple grain aphid, can become very abundant on buds in early spring, but it causes no damage to apples and soon migrates to grain and grasses for the summer. Apple grain aphids are green with a dark stripe on its back.

Monitoring

• Aphid monitoring should begin in June by checking at least 10 terminals and water sprouts per tree and 10 trees per block. Treatment threshold is 50% of vegetative terminals infested AND less than 20% of infested terminals with biocontrol agents present OR 10% of fruit with honeydew or aphids.

Management

• Limit nitrogen fertilization to the level necessary for optimum tree growth.
• Summer prune to remove water sprouts.
• Two predators offer excellent potential for biological control and can often be found among aphid colonies. Syrphid fly larvae are small, legless, tan-green mottled maggots and Cecidomyiid fly larvae are small, orange maggots. Both are voracious feeders, capable of consuming dozens of aphids before completing development
• If finding aphid populations above threshold, consider waiting one week and then check again for biocontrol agents. If treatment threshold is still exceeded, apply an insecticide.

Overview

Rosy apple aphid feeding results in stunting of new growth and may cause sooty mold to develop on fruit and leave. As they feed, rosy apple aphids inject a toxin with their saliva that causes the leaf to curl and the fruit to be distorted. Of the aphid species that can be found on apple trees, the rosy apple aphid causes the most severe damage and is the most difficult aphid species to control.

Biology

The aphid overwinters on apple trees as eggs laid on twigs, bud axils, or in bark crevices. The black eggs are 1/2 mm long and football-shaped. The overwintering eggs give rise to only female aphids which give birth to live young. Shortly after silver tip the eggs hatch. The nymphs' color changes from dark green to slightly purplish or dull pink with variable amounts of greyish-white wax bloom. The aphids continue to reproduce on apples until summer, then winged forms are produced which migrate to other hosts such as dock and narrow-leaved plantain to spend the summer. Recent evidence, however, shows that the biology of this pest has changed and populations in orchards may no longer need to go to the alternate host plantain but can breed continuously on apple. In the late fall, winged forms migrate back to apples and lay eggs in bark crevices and on twigs.

A cool, wet spring favors aphid development because it provides conditions unfavorable for parasites and predators of aphids.

Damage

These aphids cause a decrease in tree vigor because of foliage loss and damage to the fruit through dwarfing, misshaping, and staining. The rosy apple aphid injects a toxin with its saliva that causes the leaf to curl and the fruit to be distorted. A single stem mother located on the underside of a leaf near the midrib will cause the leaf to fold almost as tightly as the outer wrappings of a cigar. The presence of only a few stem mothers can cause severe curling of all leaves surrounding an opening flower bud; within such curls, ideal protection is afforded to the rapidly developing aphids.

‘Cortland', 'Ida Red', and 'Golden Delicious' are the varieties most frequently showing fruit injury. Fruit adjacent to rosy apple aphid colonies is stunted, puckered at the calyx end, and ridged like a pumpkin.

Monitoring

Monitoring for rosy apple aphid is possible after egg hatch begins since the eggs of apple grain aphid and apple aphid are identical to rosy apple aphid eggs. Starting at early pink, select 5 to 10 trees per block. Sensitive varieties such as ‘Cortland', 'Ida Red', and 'Golden Delicious' should be selected if present. For 3 minutes, on each tree, count the number of fruit spurs showing curled leaves. The presence of more than one aphid-infested cluster per tree justifies an insecticide treatment to prevent fruit injury. Samples should be taken from the upper parts of the canopy on the inside of the tree where rosy apple aphid colonies are most common.

Management

The green apple aphid, apple-grain aphid, and rosy apple aphid overwinter as eggs on twigs and bark crevices of apple trees. A delayed dormant oil application between green-tip and half-inch green controls newly hatched aphids.

Before leaf curling, an organophosphate insecticide or a 1 to 2 % application of insecticidal soap or summer horticultural oil can provide effective control of these aphids. Thorough coverage is essential. After petal fall, because the curled leaves protect the aphids, then the best control will be achieved with a systemic insecticide. Some insecticide options include Admire Pro and Movento (active ingredient: spirotetramat*, at a rate of 6 to 9 fl. Oz). 

*Spirotetramat is an insecticide derived from tetramic acid, a systemic material, for the control of sucking insects in their juvenile, immature stages, including aphids, scale insects, and whitefly. It produces growth inhibition of younger insects, reduces the ability of insects to reproduce, resulting in mortality. Spirotetramat is harmless to slightly harmful to beneficials such as hoverfly larvae, spiders, predatory bugs, wasp parasites, lady beetles and lacewings.

Overview

WAA is a reddish brown aphid covered with a white wax mass produced by specialized dermal glands. This wax mass gives the insect its characteristic woolly appearance. WAA have a complex life cycle that can involve overwintering either on apple or elm. Once on apple they move to feeding sites on roots or above ground. Root feeding produces knotty galls, and extensive feeding severly taxes the root system. Unfortunately, the above-ground WAA population is not a reliable indication of the root-feeding population. Above ground, crawlers settle in bark crevices, pruning cuts, wounds, leaf axils, and occasionally the stem or calyx of fruit. Black sooty mold fungus can develop on WAA honeydew.

Biology

• WAA overwinter as eggs on elm trees. In early spring, wingless females remain feeding on elm for 2 generations. Winged females are then produced and migrate to apple trees late in June.
• Once on apple, 'crawlers' are produced that spread throughout the tree. Several generations are produced on apples each summer. Large nymphs have a purplish body, concealed by tufts of "wool", which are actually fine wax strands.
• In the fall, winged forms are again produced that migrate back to elm and deposit overwintering eggs.
• Colonies can persist on apple roots throughout the year.

Monitoring

• Monitor for WAA in mid-late summer when, if present, colonies of nymphs or adults become most visible.
• Because of poor coorelation of above and below ground populations, there is only a tentative treatment threshold of 50% of pruning wounds.  Sample 10 possible infestation sites per tree on at least 10 trees per block.
• Should WAA infestations appear on substantial numbers of leaf axils of terminals or fruiting spurs, treatment may be warranted to reduce possible injury to developing buds.

Management

• WAA are resistant to many commonly used insecticides. Apply an effective insecticide in summer if warranted.
• Best control is obtained when insecticide is applied in July when small WAA colonies appear on periphery of canopy, but this is before colonies are easily visible.
• Some insecticides can be applied to soil to manage WAA infesting roots.

Overview

Female AM deposit single eggs under the skin of apples and, once hatched, larvae tunnel through apple flesh leaving brown trails. Egg-laying punctures are difficult to find unless the fruit is heavily attacked, as are most apples in an abandoned orchard.

Biology

• Adult AM is slightly smaller than the common house fly, with a bright white spot at the center of the dorsum (back), 4 black wing bands (3 of which look like letter F), and 3 or 4 white stripes on the abdomen. Mature larvae are 3/8 inch long, legless, white, peg-shaped, legless larvae.
• Apple maggot flies overwinter in the soil as pupae, and emerge as adult flies in June - July. They migrate to apple trees from unsprayed or abandoned trees and are known to migrate for at least half a mile. Once adults emerge from the pupae in the soil, they feed and mate. About 10-14 days after adult emergence females start depositing their eggs. Larvae feed for 3-4 weeks before leaving fruit and entering the soil.
• Activity usually ceases in late August or early September but can extend into October on late cultivars.
• There is one generation per year.

Monitoring

• AM adult flies can be monitored using sticky coated red spheres that mimic ripening apple fruits or with yellow sticky boards which act as a leaf mimic. The addition of an apple odor-based 5-component lure (commercially available at Trece, Inc.) increases AM trap captures.
• Set out traps in late June at the rate of 1 trap per 3-5 acres, but not less than 3 traps per block. Place traps near the block periphery, 1 or 2 rows in from outermost row. Remove any leaves or fruit touching the traps.
• Apple varieties most susceptible to maggot attack are Wealthy, Cortland, Gravenstein, Red and Golden Delicious, and early sweet or subacid varieties. However, AM will attack any variety.

Management

• Recommended treatment threshold is an average of 2 AM per unbaited trap or 5 AM per baited trap.
• Trap captures for a week following insecticide treatment are ignored. Subsequent sprays can be applied once the threshold is reached again.

Overview

Several species of borers attack apple trees in New England, especially young trees. Dogwood borers are probably most damaging, but roundheaded apple tree borers, apple bark borers, flat-headed apple tree borers, and leopard moths can also be found. Black stem borers, a tiny bark beetle, has recently been attacking stressed apple trees in New England.

Biology

• Dogwood borers and apple bark borers are small wasp-like moths that lay eggs in bark crevices, primarily in burr knots and callus tissue around graft unions. Caterpillars grow up to 3/4 inch long, with an orange tinge. Caterpillars bore in bark, not wood, producing reddish frass on bark surface. Adults fly from mid-June through late August with peak flight in July. Trees with many burr knots (such as M9) are most heavily infested.
• Roundheaded apple tree borers are striped long-horn beetles about 5/8" long that emerge during the month following Petal Fall. Most egglaying occurs from late June to early August, and usually within a couple of hundred yards of where the female emerged. Larvae tunnel through trunks until completing the 2-3 year life cycle.
• Flat-headed apple tree borer is a dark/brown beetle belonging to the family Buprestidae. Adults are about 1/2" long with a metallic luster. They are primarily active in June and July on the sunny sides of trees. Eggs are deposited in bark crevices. Sinuous trails in the bark are visible without cutting into the tree. Eventually, the grubs bore into the wood, leaving tunnels that are oval in cross-section. Grubs are legless with a broad, flattened head end and a cylindrical body. Weakened, stressed or strongly leaning young trees are most frequently attacked.
• Leopard moth (Zeuzera pyrina), lay eggs in bark crevices in July and early August. Larvae bore into the bark and quickly move into the wood. They are usually first noticed because of the moist, fibrous droppings that are pushed out of tunnels. Caterpillars are white or pink with a dark head, and up to 2" long. The life cycle spans 2-3 years.
• Black stem borer is a very small – about 2 millimeters – ambrosia beetle (Xylosandrus germanus) that attacks stressed and apparently healthy trees, and in particular young trees, with trunk diameters of less than 2.5 inches. The insect is rarely seen outside of its galleries and only females emerge from the galleries they create to infest new trees. Signs of infestation include round entrance holes that are approximately 1 millimeter in diameter, toothpick-like strings of compacted boring dust and frass emerging from the holes, and sometimes weeping or oozing of plant sap from the holes.

Monitoring

• Look for signs of black stem borer infestation within 1 meter of the ground and use a simple trap to capture females. Cut two to four windows in the body of a plastic 1- or 2-liter bottle that has a cap. Hang it in the orchard upside down at a height of 1.5 to 3 feet, near wooded areas or in low areas where trees are prone to cold injury and where there are trees with signs of infestation.

  Bait the trap with ethanol using one of the following three methods:
  1. Squirt about a quarter cup of ethanol-based hand sanitizer (unscented) into the cap end (bottom) of your trap.
  2. With the bottle capped, pour in a cup of cheap vodka through one of the holes made in the side of the trap.
  3. Purchase a ready-made ethanol lure to hang inside the trap and fill the bottom of the trap with soapy water.
  If using hand sanitizer, traps must be checked daily because the sanitizer will form a crust on the surface after 24 hours. If using vodka or a purchased lure, traps should be checked at least once per week. Beetles are very tiny and require the use of a microscope and training to identify them correctly to species.

• Leopard moth adults can be monitored with pheromone traps.

Management

• Refer to the spray table for Summer Sprays.  One course spray of Assail to trunk between pink and mid-June. If fresh borer activity found in early July, spray Assail before early August.
• Dogwood borer management can be aided with mating disruption dispensers.
• For black stem borer management, apply insecticide when adult beetles are first caught in traps. Once beetles are inside trees, insecticides are ineffective because larvae do not feed on plant material.

Overview

BMSB is an invasive stink bug that feeds on a wide variety of host plants, including a variety of fruits (e.g., apples, stone fruits including peaches and apricots, figs, mulberries, citrus fruits and persimmons), vegetables (e.g., beans, corn, tomatoes and soybeans) and many ornamental plants and weeds. BMSB is currently distributed in 43 US states and 4 Canadian provinces.

BMSB is considered to be a landscape-level threat. This means that adults frequently switch between cropped land (agronomic crops, fruits, vegetables, ornamentals) and wooded habitats. BMSB nymphs and adults feed by inserting their piercing-sucking mouthparts into fruit, nuts, seed pods, buds, leaves, and stems and appear to prefer plants bearing reproductive structures. Their mouthparts can penetrate very hard and thick tissue, such as the hazelnut hull.

Biology

During the winter months, BMSB enters a type of hibernation called diapause. During this time adults do not feed and do not reproduce. Overwintering takes place in forested areas as well as inside houses and other buildings. In the spring, BMSB adults emerge from overwintering sites (houses, barns, storage buildings, and dead trees) and become active on nearby crops during warm sunny days. In the spring and throughout the summer, adults feed, mate, and lay eggs.

Monitoring

Commercially available traps and pheromone lures for BMSB monitoring provide valuable information on the presence/absence of BMSB and also help to decide if insecticide treatments are needed to manage this pest. Ag-Bio, Inc. (http://www.agbio-inc.com), Great Lakes IPM (http://www.greatlakesipm.com), Trece, Inc. (http://www.trece.com) and Sterling International are some of the companies that sell monitoring systems for BMSB. Monitoring for BMSB can start in late-May and needs to continue until early- or mid-October.

Monitoring devices.

• Black pyramid traps. Stink bugs, including BMSB, are visually attracted to tree silhouettes. The trap recommended for monitoring is a black pyramidal trap, which represents trunk mimic, coupled with a capturing device.
• Double-sided clear sticky cards. Researchers have found that double-sided clear sticky cards (6 x 12 inches), attached to a wooden pole, can be used for monitoring purposes. Cards are easier (and cheaper) to deploy than black pyramid traps.

Pheromone lures: Various companies are now marketing the male-produced aggregation pheromone of BMSB. Some pheromone lures incorporate the pheromone of multiple stink bug species, including BMSB. Therefore, efforts need to be made to correctly distinguish BMSB from other similarly-looking stink bugs.

Thresholds. Insecticide applications to apple orchards are recommended when a cumulative threshold of 10 BMSB/trap is reached. After the spray, the threshold is reset and subsequent trap accumulations reaching 10 adults per trap will trigger successive management sprays as the season progresses. This threshold is likely to work in peach orchards as well.

Management

Insecticide sprays is the most effective control method for BMSB. It is important to select effective insecticides given that adult BMSB are hard to kill. Whenever possible, target the nymph stage, as nymphs are more sensitive to insecticides than adults. Multiple applications may be needed with re-infestation.

The overwintering generation of BMSB tends to be more susceptible to insecticides than the summer generation. Therefore, products with the best effectiveness against this pest should be used later in the season.

Insecticides should be rotated among products in different classes with different modes of action to delay the onset of resistance to pesticides.

Overview

Larvae cause two types of fruit damage: deep entry, where larvae burrow down into the core of fruit, pushing frass out as they go; and shallow entry where feeding occurs, but no tunneling is present. Both forms of damage render fruit unmarketable. Second generation larvae cause the most damage. 

Biology

• Codling moth overwinters as a full-grown larva. Pupation occurs during bloom. First adults emerge at 150 DD, base 50 ℉., when counting from January 1. Warmer spring temperatures can accelerate the growth of codling moth, leading to earlier developmental milestones (like egg-laying and hatching).
• Newly hatched larvae are pale yellow with a black head, twice the width of its body. Mature larvae are pinkish-white with a brown head.
• Adult codling moth is gray-brown with alternating lighter gray and white bands across wings. Wings are marked at the back end by a coppery area that helps distinguish codling moth from other similar moths.
• Females can lay up to 100 eggs. Early season eggs are generally laid on leaves whereas later generations are usually laid on fruit.  There are usually 2 generations in New England.      

Monitoring

• Pheromone traps should be hung by bloom, on the north side of the tree at eye level. Hang traps in orchard areas where moths are most likely to enter from alternate host sites. Check traps twice a week and begin accumulating degree-days (base 50) after sustained catches in pheromone traps (biofix).
• First insecticide applications should be made ~ 250 DD (base 50) after biofix. First insecticide applications for the second generation should be made at about 1,400 DD to 1,600 DD, using the same biofix as previous spray timing.

Management

• Remove abandoned apple and pear trees, where practicable. Trunk banding can be a useful method of reducing codling moth pressure. Cardboard wrapped around trunks before larvae move to cocooning sites will cause them to pupate on the cardboard, which is subsequently removed and destroyed prior to adult emergence. Hot water treatment of storage bins can destroy a number of overwintering larvae.
• Mating disruption, set up before bloom, can be an effective way to reduce codling moth populations. Mating disruption is also needed in July for the second generation. Plan on supplementing mating disruption with insecticides. Using mating disruption in conjunction with insecticides is especially important for orchards with recent history of CM fruit injury or in the first year of a disruption program.
• Many insecticides are effective against codling moth when applied against newly hatching larvae. Resistance to pyrethroids and organophosphates, however, has been found in many areas of the Northeast.

Overview

EAS larvae feed under apple skin producing a heavily russetted, winding scar often seen on mature fruit at harvest.

Biology

• EAS overwinter as mature larvae in the soil. Larvae pupate and adults emerge when apples buds are in Pink stage.
• Adult EAS are clear winged, fly-like insects about 1/3 inch, dark brown above, and orange to yellow below.
• After feeding on apple pollen, EAS females cut slit into calyx end of tiny, developing fruit and insert an egg.
• Newly hatched larvae burrow just under apple skin leaving winding scar. (By harvest this scar is visible as a heavily russetted, winding scar.)
• If not controlled, larvae migrate to a second fruit and tunnel to the core. Frass can usually be seen on the surface of these apples, which drop to the ground by July. Mature larvae are 1/2 inch long, yellowish-white, and posses a pair of legs on each body segment.
• Full-grown larvae enter the soil where they remain until the following spring.

Monitoring

• EAS damage occurs more frequently when bloom time is extended and petal fall insecticide applications are delayed.
• White sticky traps placed before bloom can help determine the need for EAS insecticide at Petal Fall. Traps should be placed near blossoms at head height on the south side of at least one tree per 3 acres. Insecticide application may be warranted if more than an average of 6-9 EAS per trap are captured by Petal Fall in a block that received prebloom insecticide (or 4-5 in a block that did not receive prebloom insecticide).

Management

• Generally insecticides applied at Petal Fall adequately control EAS. Insecticide application is directed at early, superficially-burrowing larvae. Since apple varieties enter Petal Fall at different times, separate Petal Fall treatments may be needed.
• Prebloom insecticide for EAS is not needed except possibly for blocks where Petal Fall insecticide has historically not given satisfactory control.

Overview

Green pug moths have been found in New England since the 1990s. The yellow-green larvae are inchworms that bore into flower buds at bud break and feed, causes blossoms to abort. One larva can damage several flowers and, where numerous, can significantly reduce fruit set.

Biology

• GPM overwinter as eggs on apple trees, hatch at bud break, and enter buds to feed. Young larvae are olive green with black heads and look like winter moth young larvae.
• Larger GPM larvae are green and develop a dark red-brown stripe along the back.
• Most larvae finish feeding by Petal Fall, pupate in folded leaves, and emerge as adult moths in June and July.

Monitoring

• Examine flower buds for caterpillars at Tight Cluster to early Pink. Tentative treatment threshold is 6 or more GPM larvae per 100 fruit clusters.

Management

• Apply insecticide at early Pink if exceed threshold.

Overview

White apple leafhoppers (WALH) and rose leafhoppers (RLH) feed on the underside of leaves producing small, whitish spots on the upper leaf surface. This "stippling" may cover the entire leaves and appear silvery. Leafhopper feeding can reduce tree vigor, but of more concern is the accumulation of LH excrement on apple surface. The LH leave dark, "tar spots" and is difficult to remove.

Potato leafhoppers (PLH) do not overwinter in here, but migrate north with summer storms, usually reaching New England in mid June. PLH nymphs and adults feed primarily on immature leaves and actively growing shoots in the outer part of the canopy. Leaves injured by PLH feeding turn yellow on edges, cup upward, and later turn brown or scorched. On mature trees, PLH damage may not be significant, but feeding on young trees stunts shoot growth.

Biology

• WALH overwinter as eggs beneath tree bark. Hatching begins just before Bloom and is completed in 10-14 days. Nymphs migrate to leaf underside and feed, advancing into adults by mid-late June. These adults deposit eggs on leaves in July which hatch in early August, producing adults in August and September.
• RLH overwinter on rose species such as cultivated and multiflora rose. First-generation RLH adults migrate into orchards from nearby multiflora rose in early-mid June. Second-generation adults, present in July and August, deposit eggs mostly in orchards. In September, 3rd generation adults can cause extensive excrement spotting of fruit and be a nuisance to pickers before emigrating to rose bushes to deposit overwintering eggs.
• WALH and RLH adults look similar, but large nymphs of the two species can be distinguished with a hand lens. RLH nymphs have rows of small dark spots on their backs. Timing can also be used to distinguish the 2 species. LH found during Petal Fall are most likely WALH.
• PLH nymphs and adults are pale green. When disturbed, nymphs move rapidly in a sideways fashion.

Monitoring

• To monitor WALH and RLH, check 10 interior fruit cluster leaves per tree on 10 trees per block. The tentative treatment threshold is 3 WALH or RLH nymphs per leaf in June. However, growers who have had troublesome LH populations at harvest may want to use a lower threshold of 25 nymphs per 100 leaves in June.
• For PLH, sample the youngest shoot leaves in the outer canopy. Tentative threshold of one PLH per leaf.

Management

• LH have developed resistance to several insecticides. Insecticides are most effective against young nymphs. Older nymphs and adults are usually less easily controlled.

Overview

Apple blotch leafminer and spotted tentiform leafminer hosts include apple, pear, cherry, plum and quince, favoring apple leaves.The first 3 larval instars feed on tissue between the two epidermal layers of the leaf causing a translucent, 'sap feeding' mine that is visible only from the underside of leaf surface. The last 2 instars feed more extensively on leaf tissues and their 'tissue feeding' mines are visible from both the top and underside of leaves. 'Tissue feeding' mine on upper leaf surface contains numerous white dots.

Biology

• LM overwinter as pupae within mines on fallen leaves.
• Adults emerge in late April to early May and deposit eggs singly on leaf underside. Adults are 3/16 inch long, light brown moths that appear shiny in flight, with white spots that look like transverse bands when wings are folded. ABLM is nearly indistinguishable from STLM, but has forewings that are usually smaller and less heavily marked with white scales than STLM.
• Eggs hatch in 5-16 days and feed just below the lower leaf epidermis as 'sap feeders'. By late May larvae begin feeding just below the upper leaf epidermis, producing densely spotted mines visible on the upper leaf surface.
• There are 3 generations per year.

Monitoring

• Insecticide applications against 2nd generation mines normally not necessary unless mines exceed 1mine per fruit cluster leaf during 1st generation (by early June).
• Spur and leaf sampling for 2nd generation sap feeding mines allows effective timing of spray applications. Best time for insecticide application is when earliest 2nd generation mines are visible from the upper leaf surface (less than 10% have advanced to tissue feeding stage).
• Two parasitic wasps commonly attack LM larvae and can be found inside tissue feeding mines. Level of parasitism required for adequate LM biological control LM is unknown. Being aware of parasitoid development and behavior in orchards may aid in LM management.

Management

• If needed, spray insecticide when 2nd generation mines begin to advance to the tissue feeding stage. Selective insecticides allow parasitoids to substantially reduce larval populations.
• Second insecticide application may be needed.

Overview

European red mites (ERM) and Twospotted spider mites (TSM) are the two most common mite pests in New England orchards. Spider mites suck leaf fluids and chlorophyll, resulting in "bronzed" foliage. Slightly damaged leaves cause little or no adverse effect to crop. Extensive leaf bronzing results in decreased photosymthesis, often causing reduced fruit size, premature drop and reduction in fruit set the following year.

Biology

• ERM overwinter as eggs on smaller branches, twigs, and roughened bark of apple trees. Egg hatch begins at Tight Cluster, is about half complete by Pink, and is complete by Petal Fall.
• TSM overwinter as adult females primarily in orchard ground cover, where they feed on weeds and grasses. In mid-late summer, TSM migrate into fruit trees and feed on leaf undersides. There may be 10 generations per season.

Monitoring

• Mite injury during the weeks following Petal Fall can damage fruit crop. Monitor mite populations by examining underside of fruit cluster leaves through May and June. Action threshold is 1-2 motile (not eggs) mites per leaf or 30% of leaves with one or more mites.
• Starting in July, examine middle aged leaves for motile mites. Threshold for July is 5 mites per leaf. August 1-15 threshold is 7.5 mites per leaf.
• Mites tend to build up during periods of hot, dry weather. Mite populations tend to build up in "hot spots" rather than uniformly throughout a block. Hot spots tend to form on trees adjacent to dusty, dirt roads and in certain cultivars such as Red Delicious and Empire.

Management

• Oil is recommended at the 2-3 gal rate during the dormant period. Use 2 gal rate until Tight Cluster and reduce to 1 gal rate from Tight Cluster to Pink. Good coverage is essential (300 gal/A recommended).
• Many beneficial insect and mite species prey on pest mites and provide some level of biological control. Minimizing the use of pesticides harmful to mite predators is critical for conserving natural enemies and enhancing biological control of mites. A predator/prey ratio of 1:10 may provide adequate biological control.
• Several miticides are limited to 1 application per season to delay pesticide resistance developing.

Overview

OBLR attacks mainly apple and occasionally pear, peach, and cherry. Larvae feed on fruit skin, often close to the apple stem or where two apples are in contact. OBLR roll up leaves and hide in these shelters. Injuries occurring early in the season cause pronounced deformations of the fruit and are impossible to differentiate from the damage of green fruitworms. Late season fruit feeding causes small pits in the fruit surface that may go undetected until after long-term storage.

Biology

• OBLR overwinter as small larvae in trees. Overwintering larvae become active when trees break dormancy, and they complete their development about 3 weeks after Bloom. Larvae are yellowish-green to olive green; head and thoracic shield vary from tan to brown or blackish.
• Adults begin to emerge in late May or early June. Adult wings are beige, tinged with red. Forewings are crossed with oblique brown bands.
• Females can lay up to 900 eggs during a 7- to 8-day oviposition period. Eggs are green and deposited in a mass on upper leaf surfaces.
• Eggs hatch in about 10 to 12 days. Newly hatched first generation (summer) larvae move to and feed on tender growing terminals, watersprouts, or developing fruit. As these larvae reach the third instar, they display an increasing propensity to damage fruit. This generation takes almost two months to complete development.
• Adult flight of the second generation occurs in August, and the subsequent larvae hatch in August and September. The second-generation larvae feed primarily on leaves until they enter diapause, although they may occasionally damage fruit. Young larvae construct hibernation sites on twigs or bark to spend the winter.

Monitoring

• Scout for larval shelters during Bloom to Petal Fall. Examine 10 bud clusters per tree for  OBLR larvae and apply Bt insecticide if find more than 3% infested clusters.
• Monitor OBLR adults with pheromone traps and use a degree-day developmental model to time insecticide sprays against hatching larvae.

Management

• A Petal Fall insecticide spray should control overwintered larvae.
• Using the date of first OBLR capture as a biofix, use degree-day model to determine when OBLR eggs are hatching and most susceptible to insecticide. Apply insecticide starting at 360 DD (base 43F) after 1st adult trap capture. May need 2-3 sprays 10-14 days apart.
• Thinning of fruit and pruning water sprouts in midsummer is helpful in reducing fruit damage.
• OBLR may be difficult to control with insecticides, even with selective insecticides (Bacillus thuringiensis and insect growth regulators). Selective pesticides will preserve important natural enemies. More than one spray may be needed during the summer because of this species' extended flight and egg-laying periods.

Overview

Native to China, OFM is now found throughout much of the world. The adult OFM is approximately 1/4 inch (6.5mm) long and has a faint gray-brown salt-and-pepper pattern on its wings. Pupae are reddish-brown. Fully developed larvae are about 1/2 inch (12.5mm) long, pink to white in color. Eggs are about 1/32 inch (0.7mm) in diameter, yellow-white, and laid singly on leaves or twigs.

Biology

OFM overwinters as a fully-grown larva (caterpillar), on limbs or trunk. First-generation moths appear in May, and females lay their eggs on upper leaf surfaces, frequently on the terminal leaf of a young shoot. When the caterpillar hatches, it bores into the shoot primarily of stone fruits, causing the terminal to wilt or “flag”. Later generations attack the fruit of both stone fruit and apples. In the northeastern United States, the OFM usually has 3 generations (flights) per year, depending on weather conditions. As fruit develop the larvae will often enter near or through the stem end of stone fruit or calyx end of apple and bore directly into the interior of the fruit. OFM larvae do not feed on the seed; in contrast, codling moth larvae do feed on apple seeds.

Monitoring

Pheromone traps are available to monitor OFM activity and effectively time sprays. Traps are placed in the inside of the tree at eye level or higher. Follow manufacturers’ guidelines for proper trap and lure maintenance and replacement. One trap per ten acres is recommended for commercial orchards, with a minimum of two traps.

Place sex pheromone traps in early April and check at least three times a week until biofix (i.e., first sustained capture of two or more moths per trap) is established. Then, calculate and record degree days to determine the percent egg hatch for each generation and timing of insecticide sprays (see ‘management’ below). Continue to monitor traps weekly throughout the season. Pheromone-baited OFM traps will also catch lesser apple worm, so it will be important to know how to distinguish between the two.

The apple lesserworm is native to eastern North America. Adults are gray-brown moths quite similar to OFM but smaller (about 1/3 inch long with 7/16 inch wingspans) and with more brown-orange patches on the wings. When the moth is at rest, a gold band becomes evident across its back

Management

Several management options are available for OMF including insecticide sprays and mating disruption. Regardless of the type of OFM management method chosen, careful monitoring is critical to the success of IPM tools.

Chemical control of the OFM can be improved by using a degree-day model to establish optimum timing of insecticide sprays targeting newly hatched larvae since most insecticides are not effective at controlling adults. The most important spray against OFM on peaches is for the first generation. Keep in mind that there is a lag period for egg hatch after the moths fly. The first insecticide spray for OFM often coincides with petal fall, so sprays targeting plum curculio should also control the 1st generation of OFM.

Control measures for the second-generation egg hatch ought to occur at around 1,100 growing degree-days (base 45°F) after biofix.

With mating disruption, pheromone (sex attractant) dispensers are placed throughout the orchard. As the pheromone is released from the dispensers, male moths that normally use the pheromones to locate females become confused and fail to locate females. This interferes with the mating process. The densities of pheromone dispensers per acre depend on the formulation. Pheromone traps are used to evaluate the effectiveness of the mating disruption. If mating disruption is working, the pheromone traps should catch no moths. Mating disruption is only recommended for an orchard of 5 acres or larger in size.

If codling moth is also a problem in the same block, select a mating disruption material that releases pheromones of both species.

Overview

Plum curculio  (PC) is generally considered the single most destructive insect pest in orchards. The most recognizable type of wound caused by PC is the half-moon scar, produced by ovipositing females. Prior to depositing her egg, the female first uses her mouthparts to cut a small crescent-shaped flap in the fruit skin; then, she turns around to deposit an egg. When eggs hatch, larvae tunnel into fruitlets and begin to feed. Larvae complete four instars inside the fruit in about 16 days. PC-infested fruitlets generally drop to the ground prematurely. When an egg is not viable, or a female cuts into a fruit but does not deposit an egg, the scar remains and can be seen at harvest, often making the fruit unmarketable.

Biology

• Plum curculio (PC) is a snout-nosed beetle, aka a weevil. The adult is small, about 1/4 inch, mottled black, grey and brown. When handled it will often drop and “play dead”.
• The larva is a whitish, legless grub, and its feeding in fruitlets causes premature drop. Larvae then crawl out of fallen fruitlets into the soil and pupate. Adults emerge from the soil after ~16 days and feed within and outside of orchards until cold weather drives them into hibernating spots.
• Generally, commercial orchards do not have overwintering populations within their borders. Some studies, however, have shown that PCs can overwinter inside orchard blocks that are weedy in the fall.  Wild hosts (abandoned orchards, crab apples, etc.) near orchards provide habitat which allows adult PC to migrate into orchards before and after bloom.

Monitoring

• Fruitlets should be monitored beginning at about 5 mm diameter along orchard borders to determine if new injury is occuring. If fresh oviposition scars are observed, a first cover spray should be made to the entire block. Cool, wet weather will prolong PC activity. Continue to monitor for fresh scars. If more are found, a second cover spray targeting perimeter-row trees may be needed.
• Because PC immigration and oviposition period is affected by weather patterns after Petal Fall, insecticide coverage should be maintained until 308 DD (base 50F) from Petal Fall.
• A monitoring system that makes use of attractive lures, termed the ‘trap tree’ approach, has been developed. It involves baiting the branches of one perimeter-row tree with a synergistic two-component lure comprised of benzaldehyde, one synthetic component of flowers and developing fruit, in association with grandisoic acid, the synthetic PC pheromone. By examining the fruit solely on the odor-baited tree for signs of fresh PC injury this monitoring technique has proven effective at determining, on a timely manner, whether perimeter-row insecticide sprays are required against PC after the whole-block petal fall spray. Lures are commercially available and last for the entire PC oviposition period. For more information about the ‘trap-tree’ approach to PC monitoring, contact Jaime Pinero at jpinero@umass.edu.

Management

• Management of PC relies heavily on petal fall, first and second cover insecticide applications. The first insecticide application should be made to the whole orchard in order to control PC that have migrated into the inner part of the orchard.
• Additional insecticide applications may be necessary and can be limited to the outer two rows of trees.

• Kaolin clay (Surround WP) is an OMRI-listed material that can also be complementary to conventional management strategies. Applied in suspension in water, kaolin clay produces a dry white film layer of interlocking microscopic particles on the surface of leaves, stems, and fruit after evaporation of the water. Kaolin acts as a physical barrier preventing insects from reaching vulnerable plant tissue. It acts as a repellent by creating an unsuitable surface for feeding or egg-laying.

  Surround applications begin at Petal Fall and get reapplied weekly to maintain coverage and deter egg-laying.  

• Do not apply insecticides until bloom is completely finished to reduce unwanted pollinator exposure to insecticides.  For information on rainfast characteristics of some insecticides, see the following article in Fruit Gower’s News: http://fruitgrowersnews.com/news/rainfast-characteristics-insecticides-f...

Overview

SJS infested bark has a grey, roughened appearance due to scale insects on limbs and trunk. Infested fruit develop a reddish-purple ring surrounding each spot where a scale settles.

Biology

• Adult scales are round (females) or oval (males), about 1/16 inch in diameter, and greyish with a raised yellow nipple in the center. Immature SJS overwinter on twigs and branches under scale covering. Around Bloom, winged males emerge, seek out female scales, and mate.
• Tiny, bright yellow nymphs or "crawlers" emerge in mid-late June. Each female produces several hundred living young which disperse over the tree in search of suitable feeding sites.
• As crawlers mature they produce a whitish secretion that blackens with time and hardens into a waxy protective covering.
• Second generation male flight and mating usually begin by mid-July, producing crawlers by mid-August.

Monitoring

• Crawler emergence can be monitored using a band of black electricians' tape wrapped around an infested limb and coated with a thin layer of petroleum jelly. Tape should be inspected daily with a hand lens until active crawlers are found.
• The decision to treat is usually based on finding infested fruit at previous year's harvest. Examine 50 fruits per tree on 2 trees per acre and treat if you find more than 0.1% fruit with SJS injury.

Management

• Thorough, yearly pruning helps manage SJS.
• Established, heavy SJS populations are difficult to manage and may require both semidormant oil application and insecticide application targeting crawlers.
• For best results, apply 60-70 sec oil (3 gal/100 gal for heavy infestation, 2 gal/100 for others) around Half Inch Green.
• Apply insecticide when crawlers become visible. Some insect growth regulator insecticides have been very effective at controlling crawlers.

Overview

Spongy moth caterpillars damage fruit trees by feeding on leaves, flowers, and fruit. Generally spongy moths do not require management, but periodically, populations build up to very damaging levels.

Biology

• Spongy moths overwinter as egg masses in woods surrounding orchards and hatch in late April to early May and feed on leaves through June. Spongy moths are seen every year, but usually do not cause problems in apple orchards unless spongy moth populations are very large.
• Small caterpillars can blow into orchards from surrounding woods.
• Large caterpillars can walk into orchards from surrounding woods.
• Caterpillars pupate in early July and adult moths emerge mid - late July. Female moths deposit one egg mass containing 500-1000 eggs.

Monitoring

• Before eggs hatch, scout surrounding woods for spongy moth egg masses.
• From Tight Cluster through Bloom, scout leaves and buds for small, black spongy moth caterpillars. Young trees, in particular, should be monitored.
• Through the end of June, scout apple trees next to spongy moth infested woods for caterpillars walking into orchard.

Management

• Apply a Bt insecticide such as DiPel when caterpillars are 2nd instars, probably during Bloom.
• If large caterpillars migrate into orchards, apply insecticide effective against mature caterpillars such as Delegate or Altacor.

Overview

Several species of stink bugs feed on apples in New England, but the brown stink bug (Euschistus servus) may be the most common. Brown stink bugs look very similar to the invasive species, brown marmorated stink bug (BMSB). BMSB is already causing problems in some locations in New England. For more information on this pest, see the BMSB section of this guide. For updates, see https://www.stopbmsb.org.

Stink bugs' long piercing-sucking mouthparts make deep punctures that create corky flesh under the surface. The puncture is difficult to see, even with a hand lens. Each puncture may be surrounded by a small greenish area that is slightly sunken. This injury should not be confused with cork spot, which usually occurs around the calyx end

Biology

• In New England, stink bugs spend the winter as adults, hiding under stones, boards, ground cover, and weeds. In springtime, the adults become active. As the adults come out of their overwintering sites, they feed on the plants that are available.
• Stink bug nymphs and adults can begin feeding on apple flowers and continue through harvest. Native stink bugs tend to be late summer pests, but can be found throughout the fruiting season.
• Adult feeding during bloom can cause the fruit to abort, and feeding later in the summer can cause a deep cat-facing injury such as that caused by TPB, or depressed, dimpled, corky, or water-soaked areas on fruit skin.

Monitoring

• Examine developing fruit for stink bug damage and live insects.
• BMSB can be monitored with baited, black pyramid traps.

Management

• Eliminating broadleaf weeds, especially legumes, will contribute to managing stink bugs.
• Do not allow ground covers to grow under tree canopies.
• Many insecticides are ineffective at controlling stink bug populations. Apply effective insecticide at first signs of infestation. BMSB is a very mobile pest and may reinfest treated areas quickly. If repeat applications are necessary, rotate active ingredients to avoid promoting resistance in local populations.

Overview

TPB feeding up to tight cluster usually results in aborted fruit. Buds fed on from Tight Cluster through Bloom may be scarred. As apple develops, damage appears as deep, sunken areas, conical in shape, with associated light corky russetting. Damage is often confined to fruit calyx.

Biology

• TPB adults are 1/4 inch long, somewhat flattened and brown in color, with black, white, or yellow markings, including a clear-yellowish triangle on each wing tip.
• Adults overwinter in protected areas within and around orchards. They are first active on warm early spring days and become abundant from green tip through petal fall. Adults feed by inserting their mouthparts into developing fruit buds. Orchards with an abundance of legumes or flowering plants in the ground cover often have high TPB populations.
• TPB feeding up to Tight Cluster usually results in undeveloped buds that fail to set fruit. Buds damaged by feeding after tight cluster may survive but will be scarred. As the apple develops, damage often appears as deep, sunken areas, conical in shape, with associated light corky russetting, often confined to fruit calyx.

Monitoring

• TPB adults can be monitored using a visual, white sticky trap set at silver tip. Traps should be stapled to stakes or hung on low branches no higher than knee height near orchard perimeter. Use at least one trap per 3 acres and at least 3 traps per monitored block. Action threshold is cumulative average of 5 TPB per trap by Tight Cluster or 8 TPB by Pink.
• Examine 10 terminals per block for bleeding buds. Action threshold is 2-3 bleeding sites per 10-terminal sample.
• TPB activity is highly dependent on temperature, so that 2 or 3 days of warm (50-60 degrees), sunny weather triggers increased foraging and feeding behavior.

Management

• If needed, apply insecticide Tight Cluster to Pink bud stage. Use of synthetic pyrethroids may lead to outbreak of European red mites since these insecticides are harmful to beneficial mites.
• Control may be enhanced by spraying insecticide on a warm, sunny, calm day when TPB are most active.
• Destroying broad leaf weed hosts in and around the orchard in the fall may decrease overwintering TPB.
• Avoid mowing or using herbicide between Pink and Petal Fall because disturbance of alternate hosts in the groundcover may cause TPB to move into apple trees.

Overview

Winter moth caterpillars damage apple fruit by entering flower buds at Green Tip and then feeding on developing flower buds, destroying the flowers. Caterpillars continue feeding on opened flower clusters and leaves until late May.

Biology

• Winter moth are currently a problem to apple and pear growers in eastern Connecticut and Massachusetts, Rhode Island, and coastal Maine.
• Caterpillars hatch from overwintering eggs around McIntosh Green Tip. Caterpillars wriggle into buds without feeding.
• Once inside buds caterpillars feed, destroying flower parts. 100% of apple crop can be destroyed by these inch worms.
• Mature caterpillars (1 inch long) drop to the ground on silken threads in late May.
• Caterpillars pupate in the soil and remain there until late November when moths emerge. Male moths are light brown and attracted to lights; female moths are flightless and not easily seen.

Monitoring

• Set up tree wraps before moths emerge in November. Tree wraps encourage females to deposit eggs on tree trunks below the wrap.
• Check winter moth eggs for color change from orange to blue, indicating eggs will hatch in 1-3 days. Apply pesticide when eggs first begin to hatch. A Bt insecticide such as DiPel will not control hatching winter moth caterpillars.
• Scout flower buds at tight cluster and pink bud stages and apply inseciticide if many caterpillars are found.
• Winter moth caterpillars look identical to green pug moth caterpillars until caterpillars are half grown, then green pug moth caterpillars develop a burgundy-colored stripe. Green pug moths do not tend to build up to damaging levels.

Management

• In orchards with high populations of winter moths, apply insecticide when eggs begin to hatch, usually around McIntosh Green Tip. Bt insecticides, such as DiPel, not effective against newly hatched caterpillars.
• If egg hatch is delayed by cold weather, additional spray may be needed.
• Apply insecticide if finding many green inchworm caterpillars Tight Cluster - Pink.