Insect and Mite Factsheets
American plum borer, Euzophera semifuneralis, has become a major indirect pest of tart cherries after widespread use of mechanical cherry harvesters causing shaker wounds that allow this pest to penetrate bark to feed on the underlying cambium.
Apple grain aphid, Rhopalosiphum fitchii, rarely causes damage to apples, but it is the first aphid to appear on apples in spring and may appear in large, but innocuous, numbers.
Apple leafminer, Lyonetia prunifoliella, has become fairly common in young, nonbearing trees since in the 1980s, but has not resulted in economic injury.
Apple maggot, Rhagoletis pomonella, also known as the “railroad worm,” is abundant in untreated orchards and backyard trees.
Apple rust mite, Aculus schlechtendali, is commonly found, but is rarely an important pest of apple in Pennsylvania. It is usually controlled by natural predators or pesticide sprays applied against other pests such as Envidor or Portal. However, rust mite populations can build to injurious levels in some situations.
The black cherry aphid, Myzus cerasi, is the most common aphid attacking cherries, primarily sweet cherries, in most parts of North America.
Buffalo treehopper, Stictocephala bisonia, is an occasional pest of fruit trees in Pennsylvania. It gets its name from its humpbacked resemblance to the shape of a buffalo.
Cherry fruit fly, Rhagoletis cingulata, and black cherry fruit fly, R. fausta, are found on cherry, pear, plum, and wild cherry trees. These insects are common in alternate hosts, but can be effectively managed in commercial orchards.
Codling moth, Cydia pomonella, was introduced from Europe in colonial times and now occurs throughout North America as well as most of the world, wherever apples are grown.
Dogwood borer, Synanthedon scitula, was found for the first time in the 1980s as a common pest in the burr knots of apple trees on clonal rootstocks in northern Virginia, Pennsylvania, and the rest of the Northeast. Untreated infestations may reduce yields and in rare cases girdle young trees.
Since 1985, European apple sawfly (Hoplocampa testudinea) has extended its range from the northeastern portion of Pennsylvania to the Maryland border. Now this pest is common throughout Pennsylvania. Injured fruit were first reported in Adams County during 1998.
European red mite, Panonychus ulmi, a major tree fruit pest attacking apples, stone fruits, and pears, is considered by many growers throughout Pennsylvania to be one of the most important apple pests.
Spirea aphid, Aphis spiraecola, has largely displaced the apple aphid, A. pomi, in apple since the mid-1980s. The spirea aphid has a broader host range and is more likely to immigrate into apple than apple aphid, which may stay on apple year round or immigrate later in the season.
The speckled green fruitworm, Orthosia hibisci, is the most common of several green fruitworm pests occurring in commercial orchards.
The green peach aphid, Myzus persicae, is a common pest of peach and nectarine in Pennsylvania.
Gypsy moth, Lymantria dispar, may attack fruit trees, especially apple, causing defoliation that can stunt or kill young trees.
Japanese beetle, Popillia japonica, is one of the best-known pests to be encountered by Pennsylvania fruit growers, nursery operators, and gardeners. It is often the most important pest of tree-ripened peaches and can cause severe damage to other important crops.
Lesser appleworm, Grapholita prunivora, is a common species, although infrequent as a pest in Pennsylvania orchards. Larvae are general fruit feeders attacking apples, pears, peaches, apricots, plums, and cherries.
Lesser peachtree borer, Synanthedon pictipes, is an important pest in peach and cherry orchards throughout Pennsylvania and surrounding states. Problems are almost always associated with widespread incidence of Cytospora canker and, to a much lesser extent, pruning wounds, winter injury, and mechanical damage.
Mullein plant bug, Campylomma verbasci, is a “two-edged sword” of the insect world. During one part of its life it is a beneficial insect feeding on pests such as aphids, thrips, and pear psylla, but in the early season when fruits are forming it feeds on flowers and developing fruitlets potentially causing serious direct damage to the crop. An increase in activity of this pest was noted in Pennsylvania in the early 1990s.
Obliquebanded leafroller, Choristoneura rosaceana, is native to and widely distributed throughout temperate North America. Larvae feed on a wide range of plants.
Oriental fruit moth, Grapholita molesta, is a pest of most stone and pome fruits. In pome fruits, its appearance and injury is similar to that of the codling moth and lesser appleworm.
The peachtree borer, Synanthedon exitiosa, is primarily a pest of peach and nectarine trees, but it also attacks apricot, cherry, and plum. This native American borer has been known since colonial times and is a pest wherever peaches are grown.
Pearleaf blister mite, Phytoptus pyri, and pear rust mite, Epitrimerus pyri, are similar species, virtually invisible to the naked eye, that often are common on unsprayed trees.
Pear psylla, Cacopsylla pyricola, can be a limiting factor in pear production. It is a native species that produces abundant honeydew, which allows a sooty fungus to grow on the fruit surface. The result can be severe tree injury.
The pear slug, Caliroa cerasi, resembles a slug in appearance, but it is actually a sawfly. It is rarely a pest in commercial pear orchards but may appear as sprays for other insects are reduced.
Pear thrips, Taeniothrips inconsequens, was introduced early this century, probably from Europe. It can be a severe pest of sugar maple. Thrips feeding in nectarine blossoms and fruitlets in areas of the state where sugar maples are common has caused scarring injury on the fruit.
The periodical cicada, Magicicada septemdecim, is a large flying insect with a unique life history. It lives most of its 17-year life underground (Table 2-6).
Plum curculio, Conotrachelus nenuphar, is an injurious pest of apples, cherries, nectarines, peaches, and plums throughout the state.
Potato leafhopper, Empoasca fabae, is a migratory pest of many crops. It feeds on leaves of rapidly growing apple terminals and may aid in spread of fire blight.
Redbanded leafroller, Argyrotaenia velutinana, is considered a minor pest of apples and many other deciduous fruit crops throughout most of Pennsylvania.
Rose leafhopper, Edwardsiana rosae, is becoming more common on apple. Orchards in the vicinity of multiflora rose or brambles are especially at risk.
The rosy apple aphid, Dysaphis plantaginea, has been a major pest of apple trees since the end of the nineteenth century. While apple trees are its preferred host, this species also feeds on pear and hawthorn trees.
The San Jose scale, Quadraspidiotus perniciosus, is a pest of fruit trees, but it attacks many other trees as well as shrubs. Once established, most scale insects are difficult and expensive to control.
The shothole borer, Scolytus rugulosus, sometimes called the fruit tree bark beetle, is a native of Europe but now occurs throughout the United States. It attacks a wide variety of deciduous fruit trees and other trees, but it usually attacks only trees that have been weakened by some other condition.
The spotted tentiform leafminer, Phyllonorycter blancardella, affects the leaves of apple trees throughout the growing season. Problems caused by this species are presently associated with development of resistance to commonly used organophosphate insecticides.
Tarnished plant bugs, Lygus lineolaris, other plant bugs, and various species of stink bugs feed on various tree fruits and on many wild and cultivated plants and make up a unique pest complex.
The tufted apple bud moth, Platynota idaeusalis, is a serious direct pest of apples in the five-state Cumberland-Shenandoah region of the eastern United States.
The twospotted spider mite, Tetranychus urticae, while a pest of apple, peach, and other fruit trees, also feeds on a wide range of both wild and cultivated plants.
Although variegated leafroller, Platynota flavedana, is an important pest in Virginia and West Virginia, it only occasionally causes damage in southern Pennsylvania. Its biology, habits, and insecticide resistance levels are similar to those of the tufted apple bud moth.
Widespread fruit loss from western flower thrips, Frankliniella occidentalis, feeding on both nectarine and peach fruit during harvest in some areas of southern Pennsylvania and adjoining Mid-Atlantic states was first observed in early 1990. Although this species is well established, damage has been lower in subsequent years.
White apple leafhopper, Typhlocyba pomaria, has become abundant in many apple orchards throughout the state. As opposed to rose and potato leafhoppers, this species’ primary host is apple. Its pest status relates to its injury to the leaves, excrement on the fruit, and nuisance to workers.
The woolly apple aphid, Eriosoma lanigerum, is a widely distributed pest of apple trees, especially where its parasites have been killed by insecticides. It can also be found on pear, hawthorn, mountain ash, and elm trees.