Apple Direct Pests

L. A. Hull, D. G. Pfeiffer & D. J. Biddinger

Codling Moth, Cydia pomonella (Linnaeus) I. Introduction: The (CM), a native pest of Eurasia introduced into the United States over 200 years ago, now occurs throughout North America as well as most of the world, wherever apples are grown. Presently, the CM is maintained at population levels which do not seriously impact upon apple production in commercial orchards. This is because pesticides sprayed to control other pests also kill CM. However, CM is always present and has been known to infest 95% of the apples in an orchard when control measures were not taken against it. Problems with insecticide resistance are beginning to surface in the western U. S. where the CM has developed resistance to the organophosphate insecticides, primarily azinphosmethyl. II. Hosts: The CM attack the fruit directly on a wide range of plants including: apple, , quince, hawthorn, and crab apple.

III. Description: The adult female CM is approximately 3/8 inch (10 mm) long and grayish in color. The male is similar (slightly smaller) but with a pencil (a grouping) of hairs located near the wing base. The wing is generally a darker shade of gray near the base, with a dark patch containing coppery scales near the inside wing tip (Plate 1). The adults hold their wings tent-shaped over the body when at rest. The has a cream to pinkish body and brown head with dark speckles on the prothoracic shield (collar behind the head) (Plate 2). When fully grown, larvae are from 1/2 - 5/8 inch (12.5-16 mm) in overall length. Oriental fruit moth larvae, which can also be found feeding internally in apples, are smaller, lack spots on the prothoracic shield, and have a comb-like structure on the posterior end (This is described more fully in the peach section). The eggs, laid singly on the fruit or foliage, appear as flat discs slightly ovoid in shape. They are at first translucent. Later, they become reddish, and finally the dark head capsule (commonly called the black head stage), can be seen. IV. Biology: The CM overwinters as a full-grown larva within a cocoon under leaf litter, loose bark scales, or any other sheltered place it may encounter. Pupation occurs at about first pink, with first flight beginning about full bloom, and peak flight occurring approximately 2-3 weeks after full bloom and lasting until mid to late June. First generation eggs are laid on leaves near fruit or on the fruit and develop in about 8-14 days. The newly hatched larvae bore through the fruit surface (generally the blossom or calyx end) and feed near the surface for a time before boring to the core. The larvae will then feed on the seeds and surrounding flesh until full grown in 3-4 weeks. Larvae then exit the fruit, seek shelter, spin a cocoon and may or may not pupate. Most first generation larvae do pupate, emerge as adults in 2-3 weeks, and produce a second generation beginning in mid July. The majority of this second generation will overwinter as mature larvae. Those first generation larvae that do not pupate enter a quiet phase, overwinter as larvae, and begin producing eggs for first generation larvae the following year. The second generation also has individuals which may pupate and attempt to produce a third generation. This generation does not survive the winter at our latitude and is termed a "suicide" generation. Apple Direct Pests - Hull et al.

They can, however, inflict additional late season fruit injury. V. Injury: Injury to apple fruit is characterized by either (1) a tunnel emanating from the apple side or calyx and extending to the core, or (2) "stings", small shallow holes the size of a pinprick, with a small amount of dead tissue on the cavity walls. These stings are caused by early instar larvae which have been poisoned and die shortly after puncturing the apple skin. CM larvae that are feeding on the core characteristically have frass (excrement) exuding from the point of entry (Plate 3). Both types of injury will lower the value of the fruit from fresh market to processing grade and in tunneling situations, a cull. There is also the added problem of bacteria and fungi growing on stored fruits which have been injured.

2 Apple Direct Pests - Hull et al.

Plum Curculio, Conotrachelus nenuphar (Herbst) I. Introduction: The (PC) is native to North America and is primarily found throughout the mid-western and eastern apple growing regions. Most commercial orchards are relatively free from resident populations, but can be infested by adults migrating in from adjacent hedgerows and woodlots. II. Hosts: In addition to apple, the PC attacks nectarine, peach, plum, cherry, apricot, pear, quince and blueberry. The principal native hosts include American plum species, larger fruited hawthorns (Crataegus spp.) and wild crab apples. III. Description: The adult beetle (Plate 4) is about 1/5 inch (5 mm) long, dark brown with whitish to gray patches, and has three pairs of humps on its wing covers; the middle two are most discernible. The beak or snout is about 1/4 to 1/3 the body length, projecting forward and downward from its head. The PC egg is small, elliptical and pearly white. The larva, which feeds internally in the fruit, is yellowish white with a well-defined brown head capsule, and no legs. When fully grown, the larva is about 1/4 inch (6-7 mm) long, curved, cylindrical and tapered slightly at each end. The whitish or cream-colored pupa is about 1/5 inch (5 mm) long and is found in the soil. IV. Biology: The biology of PC is similar for most deciduous fruits, although the timing may be slightly different. The adults overwinter in the top few inches of leaf litter in nearby hedgerows, trashy fields and woods (especially on the south edge of an orchard). The adults initially appear in apple orchards during bloom. Most beetle activity occurs during the first warm period after petal fall, when the maximum temperature is 70°F or higher. Periods of cool, rainy weather with maximum temperatures below 70°F are not suitable for adult activity. Adults can be found in orchards for 5 to 7 weeks. Egg laying activity starts once the fruit begins to form, with egg hatch occurring after 7 days. In successfully attacked hosts, the hatching larva burrows into the fruit's center, where it makes large irregular cavities. Fruit that are successfully attacked by larvae are prone to drop prematurely. After 14-16 days within the fruit the larvae exit and enter the soil where they form a pupation chamber for an additional 10-12 days before transforming into adults. New adults can appear in the orchards in mid- to late- July with emergence continuing until early September. In September and October adults begin seeking overwintering quarters. There is only one generation per year in the mid-Atlantic region. There is a second generation in eastern Virginia and southward. V. Injury: The adults can injury the fruit in two ways during the early season: 1) feeding injury and 2) egg laying (oviposition) injury. Feeding punctures consist of small, round holes extending 1/8 inch (3 mm) into the fruit; egg punctures are distinguished by a characteristic crescent-shaped cut that partly surrounds the sunken egg (Plate 5). As the fruit matures both types of injury become corky in appearance (Plate 6). Slight feeding may occur on petals, buds, and blossoms, but there is little injury until the fruit is available. Early-blooming varieties are the first to provide suitable locations for feeding and egg laying. During the egg laying period, the female PC initially eats a small hole in the fruit, deposits an egg, and then makes a crescent-shaped slit just below the site with her snout. It is believed that the slit relieves pressure from the rapidly growing fruit and helps the hatching larva to become established. Egg laying scars appear on fruit at harvest as crescent-shaped corky areas resembling the letter "D". PC larvae rarely become established after eggs are placed in apple, although apple is frequently attacked. Apple fruit are much larger than this 's natural host fruit, and larvae are crushed by the expanding fruit. Development is more successful in peach and smaller fruit hosts such as plum, hawthorn and blueberry.

3 Apple Direct Pests - Hull et al.

Adults which successfully emerge in mid-summer can again feed on fruit. This injury appears as small, soft, irregular holes, usually near the calyx of the fruit (Plate 7). The injury usually occurs in orchards that have high amounts of egg laying injury. Adults can average over 100 feeding and/or egg punctures during their normal life.

4 Apple Direct Pests - Hull et al.

Apple Maggot, Rhagoletis pomonella (Walsh) I. Introduction: The apple maggot (AM), also known as the "railroad-worm", is a potentially serious pest, but has not been a noticeable problem in commercial orchards in the mid-Atlantic region in recent memory. II. Hosts: Apple, especially early maturing and sweet varieties, and the native hawthorns (Crataegus spp.) are the preferred hosts of AM. In addition, the AM will attack crab apple, pear, cherry, plum and apricot especially when these fruit are planted near heavily infested apple or hawthorns. III. Description: The adult fly (Plate 8) is black with three (males) or four (females) white stripes across the body and a prominent white spot in the middle of its back. The wings are clear with four black bands shaped somewhat like the letter "F." The adult is about 2/10 inch (5.8 mm) long with a 1/2 inch (12 mm) wingspan. The abdomen of the female is more sharply pointed and curved than that of the male. The maggot is small, white, and legless (Plate 9). IV. Biology: Adult flies start to emerge in mid June to early July, and continue emergence over a period of three months, with peak emergence usually in late July and August. Emergence patterns can vary considerably within the mid-Atlantic region, depending upon the type of host and environmental conditions, especially temperature, soil type, and rainfall. Emergence of adults is very low unless rain falls prior to emergence. Newly emerged flies are sexually immature and must spend time acquiring protein by feeding on honeydew excreted by other (e.g., aphids). The flies mature sexually within 1-10 days. There is a preoviposition period of about 7 days. The female fly makes a small hole in the apple skin and deposits a single egg. The egg hatches in a few days (e. g., 2-10) and the young maggot starts to feed, working its way through the fruit. Time spent within the fruit is usually 20-30 days. When mature, the maggot leaves the fruit and enters the soil to develop into the pupal stage where it remains until the following summer. There is only one generation each year. A small proportion of the population does not emerge as adults for an additional year, giving protection to the population from crop failures or biennial bearing, thus complicating control of high populations. V. Injury: Pitting and dimpling on the apple surface caused by the oviposition punctures (Plate 10), and brown, winding trails caused by the excrement of the maggot and an associated bacteria under the apple's skin (Plate 11), are characteristic of AM injury. Early maturing and thin-skinned apples are more severely infested and usually breakdown much faster. Many larvae may be found in a single apple.

5 Apple Direct Pests - Hull et al.

Tufted Apple Bud Moth, Platynota idaeusalis(Walker) I. Introduction: The tufted apple bud moth (TABM) is probably the most serious direct pest of apples in the mid-Atlantic region. Although this pest can be found in most commercial orchards, those orchards located in intensive production areas are usually more seriously affected. This has been primarily due to the increased insecticide selection pressure which has resulted in the development of resistance to the organophosphate insecticides. II. Hosts: The major hosts of the TABM include: apple, pear, peach, nectarine, cherry and a wide range of herbaceous plants found in the ground cover. III. Description: The adult female moth is approximately 1/2 inch (13 mm) long, with the males being slightly smaller. The moths are inconspicuous in color, varying from a mottled gray to brown (Plate 14). The coloration of the wings is generally one-third grayish at the wing base, with gradually darkening to brown at the wing tips. There is usually a lighter colored margin along the leading edge of the wings. The moth is named after the tufted scales which can be seen as two or three groups on the tops of the wings. The larvae are a light brown to grayish tan with a chestnut brown head capsule, a darker prothoracic shield (hardened area between the head and the body), and a dark stripe down the back of the body. A full grown larva is approximately 3/4 inch (18-20 mm) long (Plate 15). TABM deposit their eggs in a flattened, ovoid, green mass consisting of upwards to 150 eggs (Plate 16). As the egg mass matures it changes from a green to a bronze color and finally to a black-head stage which occurs within 24 hours of hatch (Plate 17). Egg masses usually hatch within 8 to 10 days of being deposited. The egg mass is always deposited on the upper leaf surface. IV. Biology: TABM produce two generations a year with larvae overwintering as second through fifth instars in larval shelters such as rolled leaves and decaying fruit. These shelters are located beneath trees in apple, cherry, peach, nectarine and pear orchards. The larvae become active in early spring, and complete development on a variety of host plants (e.g., root suckers, dandelion, dock, and wild strawberry). The larvae pupate and begin emerging as adults about the beginning of May. They begin egg-laying anywhere from mid- to late May. The peak hatch period occurs about mid-June. First instar larvae disperse by crawling or ballooning (floating in the wind on a strand of silk). First and second instars then feed along a leaf midrib, and, beginning with the third instar, they create shelters by rolling leaves after notching petioles (Plate 18), tying leaves to other leaves or fruit, and by building shelters within fruit clusters. Larvae generally pupate within these shelters, emerge as adults, and begin second brood egg-laying about the beginning of August. Peak egg laying and hatch occur in mid- to late August. Late season second brood larvae (second through fifth instars) drop to the ground during fruit harvest or with leaf fall to overwinter. Larvae are attacked by a number of parasitoids, the most common being an ichneumonid, Exochus atriceps Walsh, and an braconid, Meteorus trachynotus Viereck. V. Injury: The TABM belongs to a family of moths known as leafrollers, but the leafrolling activity has little economic impact on the fruit grower and little physiological impact on the tree. It is when this insect webs a leaf onto the apple fruit and feeds directly on the fruit that it becomes a pest. This damage appears as tiny holes (early instar feeding), as irregular scarring or channeling of the apple surface (Plate 19), or as an area of rot, generally found around the stem. Rot or corking around the stem occurs usually after the larvae have finished feeding and have pupated. Larvae occasionally enter the apple calyx and feed unnoticed within the seed cavity. Most injury to apples is caused by second brood feeding, although in some years first brood damage can exceed damage caused by the

6 Apple Direct Pests - Hull et al. following generation. Injury to fruits destined for fresh markets has a greater economic impact since their cash value is much higher compared to that of processing grade apples. Generally, TABM injury does not reduce the grade of processing apples, but it can affect the rate of fruit drop and storageability of those apples by promoting decay, both of which can have an economic impact on the grower and processor.

7 Apple Direct Pests - Hull et al.

Variegated Leafroller, Platynota flavedana Clemens I. Introduction: Although some reports state that apple is only an incidental host, variegated leafroller (VLR) is the most important leafroller in central Virginia, where it largely replaces tufted apple bud moth. It can also be important in eastern New York and a few counties in West Virginia. Like TABM, resistance to organophosphorus insecticides in this species is increasing. VLR is similar in many respects to TABM, to which it is related. II. Hosts: This leafroller has been described as a general feeder, probably most common on low growing rosaceous hosts, e.g. strawberry. In addition to apple, it has also been found on azalea, blackberry, clover, cotton, Helianthus sp., maple, peach, raspberry, rose, sassafras, and other plants. III. Description: There is considerable sexual dimorphism in this species. Males are dark brown with a golden or cream colored band on the apical quarter of the wings (Plate 20). Females have several bands of varying shades of brown or reddish-brown on their wings. There is a pale patch near the base of the wings followed by a darker brown median stripe. The outer third of the wings is paler, but with a dark spot near the front edge of the wing. Wingspan of the female is 1/2-3/4 inch (14-19 mm), that of the male is ca. 1/2 inch (12-14 mm). First and second stage larvae are yellowish with a black head capsule, and are about 1/20 inch (1.2 mm) long. Older larvae are green with a light brown or amber head capsule; the sides of the body are lighter green than the top (Plate 21). The thoracic shield is deeper amber, with the color becoming more pale towards the edge. Larvae reach a length of about 3/4 inch (20 mm). Pupae are brown and may be found in folded leaves, either on the ground or hanging by the partially severed petiole. Pupae are about 4/10 inch long (9.3 mm for females, 9.1 mm for males). IV. Biology: This bivoltine (two generations) leafroller has a similar life history to TABM. TABM is usually present to some degree in orchards where VLR predominates. However in such orchards, VLR usually has a stronger second flight, usually causing more injury than the first generation. Larvae of various ages overwinter in the ground cover, feeding on weeds (e.g. narrowleaf plantain, smartweed, dandelion, dock and others). VLR adults become active in the spring about 7-10 days later than TABM. Adults emerge from early May to mid-June in the first flight, and from mid-July to late August for the second flight. In some years there may be a partial third generation. Activity dates are shifted later in the northern part of the range. For example, first adult flight in Michigan is usually in late May. Eggs appear as flat green masses, of oval or irregular shape, usually containing 50- 70 eggs. A typical egg mass is 1/10 x 3/10 inch (3x8 mm). Females lay an average of 5-6 egg masses. Eggs undergo a progression of color through olive-green, yellow-brown, and later with black head capsules visible in each egg in the mass. Eggs are deposited only on the top surfaces of leaves. Oviposition by the first generation starts about the first week of June, peaking in late June. The egg stage lasts about 13 days in the first generation. Egg hatch starts in mid-May, peaking in mid-June. Larvae require 20-42 days to reach pupation, averaging 35. The young larva cuts partially through the leaf petiole, causing the leaf to become less turgid. The leaf is then tied to another leaf, forming a protected area in which to feed. Occasionally the leaf is tied to a fruit, leading to the feeding injury of economic concern. Second generation oviposition starts in mid-July, peaking in late July and early August. The second generation egg stage lasts about 9 days, with about 50 eggs per mass. The second generation usually causes the most injury and can be important in the weeks approaching harvest. Although this species' ranges from Maine to North Carolina and west to Minnesota

8 Apple Direct Pests - Hull et al. and Arizona, it is generally a southern species and not common above the 42nd Parallel in New York. However, it is also not common in the apple regions of North Carolina, which are higher in elevation. Larvae are parasitized by a variety of fly and wasp species, and are subject to infection by a virus (Plate 155). V. Injury: The injury cannot be distinguished from TABM There is some variability, but a shotgun pattern of isolated feeding sites is typical.

9 Apple Direct Pests - Hull et al.

Redbanded Leafroller, Argyrotaenia velutinana Walker I. Introduction: Redbanded leafroller (RBLR) was once the most important leafroller in the eastern U.S., reaching its greatest severity in the mid-Atlantic states. Although occasional outbreaks occurred early in the century, this species rose to its greatest pest status after the introduction of DDT. It is generally controlled by growers using conventional organophosphate-based spray programs, but occasional outbreaks still occur. II. Hosts: In addition to apple, RBLR has been a pest of cherry, peach, plum, grape and other small fruits, and ornamental crops. This species has a broad host range, tying leaves of most plant species except conifers. III. Description: The adults are easily distinguished by the presence of rusty red or red-brown bands extending from about the middle of the front edge of the wing (outer edge when folded) to a point about two-thirds of the distance from the wing base on the rear edge (inner edge when folded). This band forms a V-shape when at rest (Plate 22). There is a patch of similar colored scales forming a spot at the front edge of the wing, about 3/4 of the length from the wing base. There is a concentration of creamy-colored scales in the outer quarter of the forewing. There is substantial variation in the intensity of color of RBLR, more so than most leafrollers. Male wingspan is about 1/2 inch (13 mm), that of females is about 6/10 inch (16 mm). Larvae are fairly uniform green with a green head capsule (Plate 23), reaching a length of about 7/10 inch (17 mm) (14-18 mm in the female, 13-17 mm in the male). If larvae have fed on fruit, they develop a yellow tint (Plate 24). Pupae are deep brown, reaching a length of about 3/10 inch (7-8 mm). IV. Biology: RBLR has four generations in Virginia, but only two in the northern part of its range (e.g. New York). Pupae overwinter in the ground cover (in rare cases, larvae will survive the winter). In the mid-Atlantic region, adults start to fly around green tip. The peak of the first flight occurs from tight cluster to pink. Females lay eggs primarily on the trunk and scaffold limbs, mainly at pink, averaging 40-45 eggs/mass for the spring brood, 60-80 for later broods. Egg masses have a gray-green to dull yellow-orange color (Plate 25). Larger masses are about 1/10 x 2/10 inch (3x5 mm). First generation eggs hatch about late bloom or petal-fall. Larvae of this generation are present from early May to mid June. Adults emerge after a pupal period of about 8 days. There is a 1-7 day pre- ovipositional period (averaging 2-3 days). Adult males live 6-10 days on average, females 7-10 days. In Virginia, first male captures (peak catch in parentheses) of the four flights were early April (mid-April), late May (mid-June), early July (mid-July), and late August (mid-September). Eggs are parasitized by Trichogramma minutum Riley, and a complex of parasites attack larvae and pupae. Larvae are subject to infection by a granulosis virus. V. Injury: First generation larvae feed mainly on leaves, but fruit feeding can result in deeply scarred fruit at harvest. Early generation injury may be a broad irregular scar on the side of the fruit. Later generation injury consists of several interconnected feeding areas, forming a broad, shallow wound, at times reaching 1 inch (25 mm) across. Larvae may form webbing at the calyx. Larvae may feed either in the calyx or the side of the fruit.

10 Apple Direct Pests - Hull et al.

Obliquebanded Leafroller, Choristoneura rosaceana (Harris) I. Introduction: The obliquebanded leafroller (OBLR) is native to and widely distributed throughout temperate North America. Larvae feed on a wide range of plants including unrelated deciduous trees (e.g., larch). Their importance is increasing in the northeastern U. S. due to the development of resistance to certain organophosphate insecticides. There are two generations a year. II. Hosts: Although the OBLR can feed on a wide range of plants, their preferred hosts are members of the rose family. Outbreaks can occur on apple, peach, nectarine, cherry and pear trees. III. Description: Adults are approximately 3/4-1 inch (19-25 mm) long and have a wingspan of 1 inch (25 mm). Their forewings are reddish brown crossed by three alternating light and brown bands (Plate 26). The hind wings, invisible when the moth is at rest, are pale yellow. The female moth is large and more distinctly marked than the male. A female can lay up to 900 eggs during her 7- to 8-day oviposition period. Eggs are laid on the upper surfaces of leaves. They appear as greenish, yellow masses measuring about 3/16 x 3/8 inch (5 x 9.5 mm) and may contain 200 or more eggs. The black head capsules of embryonic larvae become visible prior to hatching, which usually occurs in 10 to 12 days. Larvae are indiscriminate feeders that pass through six instars. Newly hatched larvae have a yellowish, green body and a black head and thoracic shield. Mature larvae are approximately 1 inch (25 mm) long, and the head and thoracic shield may either be black or various shades of brown (Plate 27). These larvae can be confused with larvae of the fruittree leafroller. Pupae are dark brown, about 1/2 inch (12.5 mm) long, and are usually found in rolled leaves on the tree. IV. Biology: The OBLR overwinters as either second or third stage larvae within a silken case, or hibernaculum. These hibernacula can be found in the protected areas of the scaffold limbs (e.g., pruning scars). The larvae become active in the spring as the buds begin to open. They begin to feed by tying together a number of leaves with silk. Overwintered larvae feed first on watersprouts and then move throughout the tree. Those feeding on developing flower buds do so before bloom and continue to consume floral parts throughout the blossom period. After petal fall, these larvae continue to feed on developing fruit. Pupation occurs within these sheltered areas with the first adults observed during late May and early June. The first summer brood of larvae emerge and complete development in mid to late July. Newly hatched larvae of the first summer brood 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. Second- brood eggs begin to hatch in early to mid-August and feed until they reach the third instar in fall, when they construct hibernation sites on twigs or bark and enter winter diapause. These second-brood larvae feed primarily on leaves until they enter diapause, although they may occasionally damage fruit. V. Injury: Larvae primarily feed on foliage, a habit which has no economic impact on mature trees, but can seriously reduce leaf area and growth on nonbearing trees. Feeding on the developing fruit can occur at three times during the season. The first period occurs at pink through the petal fall and shortly thereafter. This feeding injury can cause fruit to abort or result in deeply scarred fruit (Plate 28). The second feeding period occurs during July when the larvae can attach a leaf to the surface of the fruit and feed. This injury is characterized by shallow feeding usually of less than 1/16 inch (1.6 mm) deep. More extensive injury may occur if larger larvae continue to feed on the fruit. Feeding injury at this time of the season may become scabbed over by harvest. The third feeding period occurs, just before, or during harvest. The type of injury caused is similar to that caused

11 Apple Direct Pests - Hull et al. by the tufted apple bud moth, that of "pin-holing".

12 Apple Direct Pests - Hull et al.

Green Fruitworms, Lithophane antennata (Walker), Orthosia hibisci (Guenée) and Amphipyra pyramidoides Guenée I. Introduction: There are several species of fruitworms affecting apple; the green fruitworm, L. antennata, speckled green fruitworm (O. hibisci) and humped green fruitworm (A. pyramidoides) are among the more important. The speckled green fruitworm is the most common. II. Hosts: A wide host range, including apple, cherry, plum, pear, apricot, strawberry, quince, willow, birch, poplar, balsam, alder, choke cherry, and maple. When densities peak generally, populations overflow into orchards. III. Description: Adults of most species are brownish moths with a wing spread of ca. 1.5 inch (40 mm) (Plate 29). Larvae of the speckled green fruitworm are light green, while the humped green fruitworm is darker green; both possess a pair of lateral white stripes, with additional white spots (Plate 30). Additionally, the humped species has a dorsal hump at the rear of the body. Mature larvae are ca. 1.5 inch (40 mm) long. Pupae resemble those of leafrollers, but are larger, reaching lengths of about 3/4 inch (20 mm). IV. Biology: Fruitworm species have one generation per year. Speckled green fruitworm overwinters as pupae in the soil, adults emerging in the early spring and invading orchards and ovipositing at the onset of tissue growth. Eggs are laid beginning at the half-inch-green stage. Humped green fruitworm overwinters as an egg. These eggs hatch with other fruitworm species' eggs. Larvae feed on leaves, buds and developing fruit; each larva may injure several fruit. When larvae are mature, they enter the soil to pupate. Adults emerge in mid-summer, fall, or the following spring, according to species. V. Injury: Foliar injury is usually not important; economic damage results from larvae feeding on young fruit. Damaged fruit may drop early; or fruit may remain at harvest with deeply sunken areas (Plate 31). Symmetrical deep round holes are often seen resulting from green fruitworm feeding. Injury may be confused with that caused by early redbanded leafroller feeding, but is usually deeper.

13 Apple Direct Pests - Hull et al.

(Tarnished Plant Bug, Lygus lineolaris (Palisot de Beauvois)) I. Introduction: Tarnished plant bug (TPB) is covered in more detail in the Peach section. Details specific to apple are included here. II. Injury: Feeding in apple that occurs before bloom usually results in buds abscising early and is rarely a problem. If feeding occurs after fruit set, fruit deformation will result (Plate 32). Injury usually consists of a discrete dimple, a deeply sunken conical area, in the side of the fruit. In some orchards this is the most important insect damage to fruit at harvest.

14 Apple Direct Pests - Hull et al.

European Apple , testudinea (Klug) I. Introduction: European apple sawfly (EAS) is a type of primitive wasp that is an apple pest mainly in the northeastern states. Its range extends into eastern Pennsylvania. II. Hosts: Apple. III. Description: Adults are dark brown on top and yellow-orange below. Wings are clear, and adults reach a length of about 1/3 inch (8 mm). are distinguished as a group from other wasps by their broad waists. Larvae resemble caterpillars (larvae of Lepidoptera) but can be distinguished by the presence of prolegs (fleshy, unjointed legs) on each abdominal segment. These are lacking on the anterior abdominal segments in caterpillars. Mature larvae are about 1/2 inch (12 mm) long. IV. Biology: Mature larvae overwinter in the soil. Pupation occurs in the spring and adults emerge at the pink stage of bud development. Males and females each feed on apple pollen. Females oviposit in the developing fruit. The female makes a slit and deposits an egg near the calyx of the young fruit. The larva mines just under the skin of the apple. After developing in the fruit, the mature larva leaves the fruit to enter the soil for the winter. V. Injury: The tunneling by the larva creates a large russeted scar forming a circle originating from the calyx (Plate 34). A single larva may leave the first fruit and tunnel to the core of a second fruit. Frass may be found protruding from the injury. Fruit with such core injury are likely to abscise in mid-summer.

15 Apple Direct Pests - Hull et al.

Lesser Appleworm, Grapholita prunivora (Walsh) I. Introduction: The lesser appleworm (LAW) is native to eastern North America, but has spread throughout most of Canada and the northern U.S. Although sometimes more abundant in abandoned apple orchards than the CM, this insect has proven to be much more susceptible to insecticides and is generally of minor importance in commercial apple orchards. II. Hosts: Only the fruits and stems of rosaceous plants are attacked by the LAW. Plum, apple, and cherry fruit are the preferred hosts, but this insect has also been reported infesting the fruits of apricot, pear, and peach as well. In the wild, the LAW is thought to utilize the fruits of hawthorn and native plum species as well as the hips of wild roses. III. Description: The adults (Plate 35) are approximately 0.28 inch (7 mm) long and have a wingspan of about 0.43 inch (11 mm). The adults are smaller than the closely related oriental fruit moth and cherry fruitworm. The front wings are dark brown in color with scattered patterns of grayish orange patches and a few thin transverse bands of shining pale blue. The two largest gold areas are found in the middle of the front wing and on top of the head. When the wings are folded in the resting position, these areas form a gold band stretching across the back. The female moth lays between 40-60 eggs. The eggs are flat oval disks 0.025 x 0.022 inch (0.65 x 0.55 mm) in size. When first laid, the eggs are white, but soon turn a yellowish color. The larvae reach a length of 0.35 inch (9 mm) with a head capsule width of 0.032 inch (0.8 mm) In size and coloring, the larvae are almost indistinguishable from those of the cherry fruitworm and oriental fruit moth (OFM). All three of these species have an anal comb which separates them from codling moth larvae, all are white with reddish-pink tinges, and all have a dark brown head capsule and thoracic shield. The oriental fruit moth tends to be paler in coloration than the other two species but methods suggested in the literature to separate the species by boiling or preserving in special fluids do not always work. The only sure method to distinguish these three species from each other is to rear them to adulthood or note the type of damage they do. The larvae pupate in tightly woven white cocoons and the golden brown pupae are about 0.20 inch (5 mm) in length. IV. Biology: The biology of the LAW is very similar to that of the CM with adult emergence of each species occurring within a week of each other during both generations. Both species overwinter as full grown larvae in hibernacula in cracks and crevices on the tree trunk, or in the leaf litter below the tree, or occasionally in the calyx end of fallen fruit. The larvae pupate within the hibernacula early in the spring, generally during May, and begin adult emergence 2-3 weeks later with peak emergence by mid-June. The eggs are laid singly on the upper surface of leaves or directly on the young fruit. Upon hatching, the young larvae immediately search for a fruit to on which to feed and begin mining the fruit just beneath the skin, generally near the calyx end. Deep internal feeding by LAW larvae in apple fruit is rare and many reports of this type of injury associated with this moth are due to confusion of their larvae with the very similar OFM larvae. The larvae of the first generation have been reported to bore into the young shoots of apple to feed in the same manner as oriental fruit moth, but this is rare. The first generation larvae complete development by mid- to late-July and may or may not leave the fruit to pupate. The first adults of the second generation begin to emerge by early August and peak emergence generally occurs by mid-August. Adult flight from this generation, however, may continue into October. Larvae of the second generation are often present at harvest and begin to form hibernacula in October. V. Injury: LAW larvae feed primarily on the fruit at either the calyx or stem ends. Only rarely are the larvae found feeding on the side of the apple. Feeding on the fruit is shallow

16 Apple Direct Pests - Hull et al.

[<0.24 inch (6 mm) deep] and the injury is in the form of a blotchy mine (Plate 36) similar in shape to the feeding injury caused by the redbanded leafroller. RBLR, however, consume the skin when they feed, but the LAW larvae feed just below the apple skin and do not consume it. There will often be an inconspicuous pile of frass near the feeding site that is characteristic of LAW feeding. Damage from the OFM is much deeper and similar to damage associated with the CM. Conspicuous dark brown frass around the entrance hole is often associated with OFM injury and the larvae with often enter the side of the apple as well as the ends of the apple fruit. Fruit infested during the first generation of LAW generally fall to the ground during June drop, but fruit infested during the second generation will often contain larvae at harvest.

17