Orchard-pest
Guides
Parornix geminatella
Unspotted Tentiform Leafminer Moth
Parornix geminatella is a leaf-mining moth in the family Gracillariidae. Its larvae create tentiform mines on leaves of Rosaceae trees and shrubs. The species has a broad distribution across eastern North America, extending from Québec to Florida and west to Colorado and Texas.
Phobetron pithecium
Hag Moth, Monkey Slug (larva)
Phobetron pithecium, commonly known as the hag moth, is a species of slug caterpillar moth in the family Limacodidae. Its larva, called the monkey slug, is one of the most distinctive caterpillars in North America, bearing nine pairs of curly, hair-covered projections that give it an appearance resembling a shed spider skin or leaf debris. The species occurs across eastern North America from southern Canada to the Gulf Coast, with adults active primarily in summer. Both larva and adult exhibit notable defensive adaptations: the caterpillar's tubercles can detach without harm to the animal, and adults display sexual dimorphism with males having translucent wings while females are drab brown with yellow leg scales and reportedly mimic bees.
Phyllonorycter crataegella
Apple Blotch Leafminer Moth
Phyllonorycter crataegella is a microlepidopteran in the family Gracillariidae, commonly known as the apple blotch leafminer moth. It is a significant pest of apple orchards in northeastern North America, where larvae create blotch mines in leaves. The species exhibits a primarily diurnal activity pattern with sex-specific flight timing: males fly intensely in the morning for mating, while females fly in the afternoon and evening for oviposition. It has three generations per year in its core range, with overwintering adults emerging in spring triggered by accumulated degree-days above 5°C.
Phyllonorycter elmaella
western tentiform leafminer
Phyllonorycter elmaella, the western tentiform leafminer, is a small moth in the family Gracillariidae. It is a documented pest of apple (Malus) in commercial orchards across western North America. Larvae create tentiform (blotch-shaped) mines within apple leaves, feeding between the upper and lower epidermis. The species serves as host to a diverse community of parasitoid wasps, with at least 14 species recorded, supporting natural biological control in orchard ecosystems.
Phylloxera deplanata
pecan leaf phylloxera, pecan phylloxera
Phylloxera deplanata is a tiny, soft-bodied insect in the family Phylloxeridae, closely related to aphids. It is a significant pest of pecan trees (Carya illinoinensis), causing the formation of galls on leaves, shoots, and nuts. The species overwinters as eggs in bark crevices and emerges in spring to feed on new growth, inducing abnormal plant tissue development. Unlike the pecan leaf phylloxera (which forms galls on leaves only), this species attacks shoots and nuts, making it more economically damaging. Heavy infestations can reduce yield, impair tree vitality, and diminish subsequent production.
Polydrusus
Polydrusus is a genus of weevils in the family Curculionidae, subfamily Entiminae, containing dozens of species distributed across Europe, North America, and parts of Asia. Several species have been introduced to North America and have become established in northern hardwood forests, where some function as polyphagous herbivores with documented impacts on tree crops. The genus is taxonomically complex, with multiple subgenera recognized including Conocetus and Orodrusus, and has been subject to recent revisionary work clarifying species boundaries and synonymies. Polydrusus species are frequently confused with the genus Phyllobius due to superficial morphological similarities, though they are not closely related.
Polydrusus formosus
Green Immigrant Leaf Weevil
Polydrusus formosus is a small broad-nosed weevil in the family Curculionidae, native to Europe and introduced to North America. Adults are strikingly metallic green due to dense emerald scales covering the body. The species is a documented pest of fruit trees and ornamental shrubs, feeding on young leaves and blossoms.
Polydrusus impressifrons
Pale Green Weevil, Leaf Weevil
Polydrusus impressifrons is a small broad-nosed weevil native to Europe, introduced to North America in the early 20th century. It is polyphagous on hardwood trees and has been recorded in hybrid hazelnut orchards in Minnesota, where it may damage buds, foliage, and roots. Adults are active from late May to mid-July. The species is smaller, lighter, and has a broader head than the similar P. formosus.
Prionus californicus
California root borer, California prionus
Prionus californicus is a large, sexually dimorphic longhorned beetle native to western North America. Adults emerge from soil in early summer and are active from June through August. Females are larger than males and produce a volatile sex pheromone to attract mates, while males possess more strongly serrated antennae. The species spends most of its life cycle underground as root-feeding larvae, making it a significant pest of orchards, vineyards, and other woody plants.
Pseudexentera
oak olethreutid leafroller, aspen leafroller, apple leafroller
Pseudexentera is a genus of tortricid moths in the subfamily Olethreutinae. Species in this genus are early-season fliers whose larvae function as defoliators of economically important trees. Three species are of particular economic significance: P. spoliana (oak olethreutid leafroller) on oaks, P. oregonana (aspen leafroller) on aspens, and P. mali on apples. Female sex pheromones have been identified for these species and are species-specific, with no cross-attraction occurring between species.
Pseudoedophrys hilleri
Peach Root Weevil
Pseudoedophrys hilleri is a species of broad-nosed weevil in the family Curculionidae. Native to Japan, it has been introduced to eastern North America and is now established in multiple U.S. states and the District of Columbia. It is the sole described species in its genus. The common name "Peach Root Weevil" suggests association with peach cultivation, though specific host relationships require verification.
Pulvinaria vitis
Cottony Grape Scale, Cottony Scale
Pulvinaria vitis is a thelytokous cottony scale insect native to Europe, now established across much of the Northern Hemisphere and beyond. It is a univoltine pest of grape and peach, with adult females overwintering on host bark and producing large ovisacs containing thousands of eggs in spring. The species exhibits distinctive discontinuous growth and feeding patterns, with three nymphal instars and limited mobility after the first moult.
Saperda candida
Round-headed Apple Tree Borer
Saperda candida is a longhorned beetle (Cerambycidae) native to North America. It is a significant pest of trees in the rose family (Rosaceae), particularly apple, pear, hawthorn, and crabapple. The species was described by Fabricius in 1787 and occurs across Canada and the eastern United States. Its larvae are roundheaded borers that tunnel beneath bark and destroy cambium tissue, often killing young or stressed trees.
Spilonota ocellana
bud moth, eye-spotted bud moth
Spilonota ocellana, commonly known as the bud moth or eye-spotted bud moth, is a small tortricid moth with a wingspan of 12–17 mm. It has a wide distribution spanning the Palearctic realm from North Africa and Europe through Asia to China, Korea, and Japan, with introduced populations in North America and Madeira. The species is univoltine, with adults flying from May to October depending on location. Larvae feed on various deciduous trees and shrubs, and the species is recognized as a pest in apple orchards where it has been studied extensively.
Stigmella
pygmy leaf-mining moths
Stigmella is a large genus of minute moths in the family Nepticulidae, commonly known as pygmy leaf-mining moths. Adults typically measure 2–6 mm in wingspan, making them among the smallest Lepidoptera. The genus is characterized by larvae that feed internally in leaf mines of diverse host plants. Many species exhibit narrow host specificity, with individual species restricted to particular plant genera or families. Stigmella contains hundreds of described species distributed across temperate and tropical regions worldwide.
Stigmella slingerlandella
Slingerland's Plum Leafminer Moth, Plum Leaf Miner
Stigmella slingerlandella is a microlepidopteran moth in the family Nepticulidae, commonly known as the plum leaf miner. The species was described by Kearfott in 1908 and named in honor of Mark Vernon Slingerland. It is a specialist leafminer on Prunus species, with larvae creating distinctive mines that begin as narrow linear tunnels before expanding into irregular blotches. The species occurs in eastern North America, where it can be a minor pest of plum and cherry cultivation.
Sympiesis
Sympiesis is a genus of small parasitoid wasps in the family Eulophidae. Species are primarily ectoparasitoids of lepidopteran larvae, particularly leaf-mining moths in the family Gracillariidae, though some species attack other caterpillar groups including Hesperiidae (skippers) and Hyblaeidae. Several species have been studied for their potential as biological control agents of agricultural pests. The genus has been documented from North America, Europe, and South Asia.
Synanthedon pyri
Apple Bark Borer
Synanthedon pyri, commonly known as the Apple Bark Borer, is a clearwing moth in the family Sesiidae. Adults are diurnal and exhibit wasp mimicry, with transparent wings and wasp-like coloration. Larvae are wood-borers that infest the bark and cambium of fruit trees, particularly apple (Malus spp.), causing damage to commercial orchards. The species is native to North America and has been documented as a pest of economic concern in apple-growing regions.
Synanthedon scitula
dogwood borer, pecan borer, Dogwood Borer Moth
Synanthedon scitula is a clearwing moth in the family Sesiidae and a significant pest of woody plants. Larvae tunnel into burrknot tissue and cambium of host trees, causing damage ranging from localized feeding to tree death. The species has one generation per year, with adults active from June through September. It is widely distributed across North America and has been recorded from numerous host species including dogwood, pecan, apple, and many other hardwoods.
Trichoferus
Trichoferus is a genus of long-horned beetles (Cerambycidae) established by Wollaston in 1854, containing at least 20 described species. Several species have become economically significant as invasive wood-boring pests, with Trichoferus campestris (velvet longhorned beetle) being particularly well-documented for its worldwide expansion through international trade. The genus includes both native and introduced species with documented associations with living trees, cut wood, and wood packaging material.
Xyleborinus andrewesi
Xyleborinus andrewesi is a small ambrosia beetle in the weevil subfamily Scolytinae. Native to the Old World tropics, it has been widely introduced to the New World. The species is polyphagous and has been recorded from 59 host plants across 29 families. It was synonymized with Xyleborinus mimosae in a 2021 taxonomic revision.
Xylosandrus germanus
black stem borer, alnus ambrosia beetle, black timber bark beetle
Xylosandrus germanus is a tiny ambrosia beetle native to eastern Asia that has become a significant invasive pest in Europe and North America. Females, which are flight-capable and substantially larger than the flightless males, excavate galleries in stressed or recently dead woody plants to cultivate fungal gardens. The species exhibits a quasisocial structure with foundress females performing distinct behavioral roles that shift from gallery construction and brood care to entrance-blocking as the colony matures. Its rapid spread—tens of kilometers per year in some regions—is facilitated by climate change, global timber trade, and an unusual reproductive system where single foundresses can establish populations through sib-mating.
Yponomeuta malinellus
Apple Ermine, apple ermine moth
Yponomeuta malinellus, the apple ermine moth, is a small ermine moth native to Europe and Asia that has become established in North America. It is a specialist pest of Malus (apple) species, with larvae that feed gregariously within silken tents and can cause significant defoliation. The species has been extensively studied as a target for classical biological control, with multiple parasitoid species introduced to manage outbreaks.
Yponomeuta padella
orchard ermine, cherry ermine
Yponomeuta padella is a small ermine moth native to Europe and parts of Asia, now introduced to North America. Adults are active from July to August and are attracted to light. The species is notable for forming part of a cryptic species complex with Y. malinellus, Y. cagnagella, Y. rorella, and Y. evonymella, requiring genital examination or host plant association for reliable identification. Larvae feed on Prunus and Crataegus species, and the moth has demonstrated invasive potential with documented outbreaks causing significant defoliation in introduced and expanded ranges.
Zeuzera pyrina
leopard moth, wood leopard moth
Zeuzera pyrina is a medium-sized wood-boring moth in the family Cossidae, commonly known as the leopard moth or wood leopard moth. Adults are highly distinctive with white wings marked by numerous black spots, giving the species its common name. The larvae are xylophagous pests that tunnel into the wood of fruit trees and other deciduous hosts, causing significant economic damage in orchards worldwide. The species is native to Europe, North Africa, and Asia, and has been introduced to the northeastern United States.