Defoliator
Guides
Acantholyda
web-spinning sawflies, pine sawflies
Acantholyda is a genus of web-spinning sawflies in the family Pamphiliidae, distributed across Europe, Asia, and North America. Species are associated with coniferous hosts, particularly Pinus and Cedrus. Several species are significant forest pests capable of causing extensive defoliation during outbreaks. Larvae construct silken webs and may enter extended diapause in soil.
Acantholyda erythrocephala
red-headed pine sawfly, pine false webworm
Acantholyda erythrocephala is a sawfly in the family Pamphiliidae, native to Europe and introduced to North America in 1925, where it became an invasive pest of pine trees. The species is commonly known as the red-headed pine sawfly or pine false webworm. Its larvae construct distinctive silken tubes for feeding and shelter, causing defoliation of host trees. The species has been the target of biological control efforts using parasitoid flies and viral agents.
Acleris
Acleris is a large genus of tortrix moths in the family Tortricidae, containing approximately 241 species as of 2007. The genus includes several economically significant forest pests, notably the black-headed budworm complex (A. gloverana-variana), which causes periodic outbreaks in North American coniferous forests. Some species are also agricultural pests, such as A. comariana on strawberries. The genus has a Holarctic distribution with records from North America, Europe, and Asia.
Acleris semipurpurana
Oak Leafshredder Moth, Oak Leaftier, Oak Leaf Tier
Acleris semipurpurana is a tortricid moth species and the most common of several moths known as "oak leaftiers." The larvae are significant defoliators of red oak group (Lobatae) trees in eastern North America. It has one generation annually, with eggs overwintering on branches and larvae feeding in spring. Outbreaks have caused considerable tree mortality, particularly in the Appalachian region during the 1960s–1970s.
Acleris variana
Eastern Black-headed Budworm, Black-headed Budworm
Acleris variana is a tortricid moth endemic to North American coniferous forests, ranging from Cape Breton Island to Alaska. The species is a recurrent epidemic defoliator of coniferous trees, with periodic population outbreaks causing significant forest damage. Larvae feed on multiple conifer genera with regionally variable host preferences. Population trends are strongly influenced by weather conditions, particularly cold, wet periods that increase larval mortality.
Allantus
Allantus is a genus of sawflies in the family Tenthredinidae. Members of this genus are herbivorous, with larvae feeding on various plants including roses, buckwheat, and dock weeds. Some species are significant agricultural pests, while others have been investigated as potential biological control agents for invasive weeds. The genus is distributed across the Holarctic region, with species found in Europe, Asia, and North America.
Allantus cinctus
Curled rose sawfly, Banded rose sawfly
Allantus cinctus, commonly known as the curled rose sawfly or banded rose sawfly, is a species of sawfly in the family Tenthredinidae. The larvae are significant defoliators of rose plants, feeding on leaf margins and capable of reducing foliage to mid-veins. When not feeding, larvae curl tightly on leaf undersides or buds, providing effective camouflage. The species produces two generations per year in temperate regions, with larvae boring into twigs to pupate.
Allantus viennensis
Curled Rose Sawfly, Rose Sawfly
Allantus viennensis is a sawfly in the family Tenthredinidae, commonly known as the curled rose sawfly. The larvae are significant pests of roses, feeding on leaf margins and causing defoliation. Adults are small, wasp-like insects with saw-like ovipositors used to insert eggs into rose tissue. The species is distinguished by the larval habit of curling cryptically on leaves when not feeding.
Alsophila
cankerworm moths
Alsophila is a genus of moths in the family Geometridae, subfamily Alsophilinae. The genus is characterized by extreme sexual dimorphism: males are winged and capable of flight, while females are wingless, flightless, and lack functional mouthparts. Adults are active in late autumn or early spring, with larvae (known as inchworms or loopers) feeding on hardwood tree foliage in spring. Several species are significant defoliators of shade trees, with populations exhibiting eruptive dynamics.
Alsophila pometaria
Fall Cankerworm Moth, Fall Cankerworm, Inchworm
Alsophila pometaria, the fall cankerworm, is a native North American geometrid moth notable for its sexually dimorphic adults: males are winged and capable of flight, while females are wingless, flightless, and lack functional mouthparts. The species exhibits a distinctive life cycle with adult emergence in late autumn and early winter, egg-laying on tree bark, and larval feeding in spring. Caterpillars are known as "inchworms" or "loopers" due to their characteristic looping locomotion. The species is a generalist defoliator of deciduous hardwood trees and can reach outbreak densities, causing significant economic and ecological impact.
Anisota consularis
Florida oakworm moth, consular oakworm moth
Anisota consularis is a saturniid moth native to southeastern North America. Larvae feed on oak foliage, often in gregarious groups, and can cause noticeable defoliation during outbreak years. The species was described by Harrison Gray Dyar Jr. in 1896 and is distinguished from related oakworms by its more restricted Florida-centered distribution.
Anisota fuscosa
Anisota fuscosa is a moth species in the family Saturniidae, described by Ferguson in 1971. It is currently recognized as a synonym of Anisota stigma. The genus Anisota includes several species of wild silk moths whose caterpillars are known as oakworms, feeding primarily on oak foliage. These caterpillars are gregarious feeders and can cause localized defoliation of host trees. Adults are typically active in spring and summer, with larvae descending to soil to pupate and overwinter.
Anisota manitobensis
Manitoba Oakworm Moth
Anisota manitobensis, the Manitoba oakworm moth, is a species of royal moth in the family Saturniidae. It is found in North America, primarily in Manitoba and Saskatchewan. Early instar caterpillars are highly gregarious, feeding in groups on oak leaves.
Anisota oslari
Oslar's oakworm moth
Anisota oslari is a saturniid moth native to the southwestern United States and Mexico. Adults are day-flying and active during summer months, with a single annual generation. The larvae are specialized feeders on oak species (Quercus), with documented hosts including sandpaper oak (Q. pungens), Mexican blue oak (Q. oblongifolia), and shrub live oak (Q. turbinella). Larvae exhibit gregarious behavior when young, becoming solitary as they mature. The species overwinters as pupae in shallow underground chambers.
Anisota peigleri
yellowstriped oakworm, yellow-striped oakworm moth
Anisota peigleri is a saturniid moth native to the southeastern United States, described by Jules C. E. Riotte in 1975. Previously misidentified as Anisota senatoria, this species is distinguished by its diurnal adult activity and specific geographic range. The larvae are specialized oak feeders that develop in gregarious clusters, causing noticeable but generally non-lethal defoliation of host trees. The species completes one generation annually, with adults active from mid-July through late August.
Anisota senatoria
orangestriped oakworm, orange-tipped oakworm
Anisota senatoria is a Nearctic silk moth in the family Saturniidae, commonly known as the orangestriped oakworm. It is one of the more common Saturniids in eastern North America, occasionally reaching pest status in the northern parts of its range. The species is notable for being a late-season feeder on oak foliage, which limits its long-term impact on host tree health. Adults are sexually dimorphic: females are larger, yellow-orange with silver-white spots and faint black lines across the wings, while males are smaller and reddish-brown. The species is very similar to A. finlaysoni in southern Ontario and A. peigleri in the southern United States.
Anisota stigma
Spiny Oakworm Moth
Anisota stigma is a Saturniidae moth commonly known as the spiny oakworm moth. The species occurs across eastern and central North America, with males uniquely attracted to light among Anisota species. Its larvae feed primarily on oak foliage. The moth was first described by Johan Christian Fabricius in 1775.
Anisota virginiensis discolor
pink-striped oakworm
Anisota virginiensis discolor is a subspecies of the pink-striped oakworm, a wild silk moth in the family Saturniidae. The larvae are gregarious feeders on oak foliage, capable of causing localized heavy defoliation. Caterpillars are visually distinctive with pink or orange longitudinal stripes and fleshy horns behind the head. The subspecies is part of a complex of oak-feeding Anisota species that periodically reach outbreak levels, though damage is typically aesthetic rather than causing long-term tree harm.
Anisota virginiensis virginiensis
Pink-striped Oakworm
A large, strikingly colored caterpillar found feeding on oak foliage in eastern North America. The larva is black with prominent pink or orange longitudinal stripes and bears a pair of black horn-like projections on the thorax. Adults are furry, tan to reddish-brown moths with reduced mouthparts that do not feed. The subspecies is distinguished from nominate A. virginiensis by geographic range and subtle phenotypic differences.
Anoplonyx canadensis
Anoplonyx canadensis is a larch sawfly native to eastern Canada, historically confused with A. luteipes and A. laricis due to similar adult morphology. The species belongs to a small genus of sawflies specialized on Larix trees, with larvae that feed on larch foliage. Detailed morphological study is required to distinguish this species from its congeners, particularly in adult stages.
Aproceros
Aproceros is a genus of sawflies in the family Argidae, comprising ten recognized species native to eastern Asia. The genus gained international attention following the introduction of Aproceros leucopoda (elm zigzag sawfly) to Europe around 2003 and subsequently to North America in 2020. This invasive species has demonstrated rapid range expansion and significant defoliation capacity on elm trees (Ulmus spp.). Most Aproceros species remain restricted to their native East Asian ranges, with limited biological information available for the genus beyond A. leucopoda.
Aproceros leucopoda
elm zigzag sawfly
Aproceros leucopoda, commonly known as the elm zigzag sawfly, is a small sawfly native to eastern Asia (China and Japan) that has become an invasive pest in Europe since 2003 and North America since 2020. The species derives its common name from the distinctive zigzag-shaped feeding pattern created by young larvae on elm leaves. Populations are entirely female and reproduce through thelytokous parthenogenesis, enabling rapid establishment from single individuals. The species can cause severe defoliation of elm trees and has recently been documented feeding on Japanese zelkova.
Archips
leafroller moths
Archips is a genus of tortricid moths in the tribe Archipini, established by Hübner in 1822. The genus contains numerous leafroller moth species whose larvae feed on a variety of woody plants, including oaks, apples, and baldcypress. Several species are economically significant pests in orchards and forests, with known outbreaks causing defoliation damage. The genus has a complex taxonomic history with multiple synonymized generic names.
Archips semiferanus
Oak Leafroller Moth, Oak Leaf Roller, Oak Leafroller
Archips semiferanus is a tortricid moth whose larvae are major defoliators of oak trees in eastern North America. The species produces one generation annually, with eggs laid in July, overwintering, and hatching the following spring. Larvae roll oak leaves with silk to form shelters, feeding inside until pupation in June. Outbreaks can cause extensive tree mortality, with over one million acres defoliated in Pennsylvania during the late 1960s and early 1970s. The female sex pheromone has been studied extensively and contains (Z)-11-tetradecenyl acetate as a primary component.
Arge ochropus
rose sawfly
Arge ochropus, commonly known as the rose sawfly, is a small sawfly species in the family Argidae. Adults measure 7–10 mm in length and are active primarily in spring. The species is native to the Palearctic region and has been introduced to northeastern North America. Larvae feed on rose leaves, causing skeletonization damage, while adults consume nectar and pollen from several flowering plants. The species produces two generations annually in temperate regions.
Asterocampa
Hackberry Butterflies, American Emperors
Asterocampa is a genus of butterflies in the family Nymphalidae, commonly known as hackberry butterflies or American emperors. The genus contains four recognized species distributed primarily in North and Central America and the Caribbean. Two species groups are recognized: the celtis group (hackberry emperor and Empress Leilia) and the clyton group (tawny emperor and dusky emperor). All species are closely associated with hackberry trees (Celtis spp.) as larval host plants.
Atomacera decepta
Hibiscus Sawfly, Mallow Sawfly
The hibiscus sawfly (Atomacera decepta) is a herbivorous sawfly in the family Argidae that feeds primarily on members of the mallow family (Malvaceae). Despite its caterpillar-like larvae, it belongs to the Hymenoptera (bees, wasps, and ants) rather than Lepidoptera. The species is known for causing significant defoliation damage to ornamental hibiscus, hollyhocks, and marsh-mallow, though it has not developed a strong preference for economically important crops like cotton or okra.
Blennocampinae
Blennocampinae is a subfamily of sawflies within the family Tenthredinidae, containing over 100 genera and approximately 600 described species. Members are characterized by larvae that often bear distinctive branched or bifurcate dorsal spines. The subfamily includes species with documented associations with woody host plants, particularly oaks (Quercus) and hickories (Carya), as well as some that have become notable urban pests. Larvae possess six or more pairs of prolegs, distinguishing them from lepidopteran caterpillars.
Cephalcia
spruce web-spinning sawflies
Cephalcia is a genus of web-spinning sawflies in the family Pamphiliidae, established by Panzer in 1803. Species are distributed across Europe, North America, and Asia. Larvae feed primarily on conifer needles, particularly spruce (Picea) and larch (Larix), and construct silk webs for protection while feeding. Several species are significant forest pests capable of causing defoliation during population outbreaks. The genus exhibits complex life cycles with variable voltinism, often involving extended diapause in soil-dwelling prepupal stages.
Cephalciinae
Cephalciinae is a subfamily of sawflies within the family Pamphiliidae. Members are characterized by their association with conifers, particularly as larvae that feed on pine needles. The subfamily includes the genus Cephalcia, which contains species known as pine sawflies. Adults are generally robust with broad heads relative to body size.
Cerotoma
bean leaf beetles
Cerotoma is a genus of leaf beetles (Chrysomelidae) containing approximately seven described species distributed across North America and the Neotropics. The genus is best known for Cerotoma trifurcata, commonly called the bean leaf beetle, a significant agricultural pest of soybean and common bean. Adults feed on foliage and pods, while larvae feed on roots and root nodules. The genus exhibits strong host associations with leguminous plants.
Chelymorpha cassidea
Argus tortoise beetle, milkweed tortoise beetle
Chelymorpha cassidea is a large tortoise beetle native to North America and the Caribbean, measuring 9–12 mm in length. Adults display variable coloration from yellow to bright red with black spots, and possess a distinctive ability to extend their red head beyond the pronotum, creating an appearance likened to the mythological figure Argus. Both larvae and adults feed on foliage of Convolvulaceae plants, including morning glory and sweet potato, and are capable of defoliating entire plants. The species overwinters as pupae in soil and emerges in mid-summer.
Choristoneura
spruce budworms
Choristoneura is a genus of tortricid moths comprising nearly forty species distributed across North America and Eurasia. Most species are serious pests of conifers, with several causing major forest defoliation events. The genus includes notable forest pests such as the eastern spruce budworm (C. fumiferana) and western spruce budworm (C. occidentalis), which undergo periodic population outbreaks that can devastate spruce-fir forests. The genus exhibits complex population dynamics and is extensively studied for its economic and ecological impacts.
Choristoneura conflictana
large aspen tortrix
Choristoneura conflictana, the large aspen tortrix, is a tortricid moth native to North America. The species undergoes periodic population outbreaks that can severely defoliate trembling aspen stands in parts of Manitoba and Saskatchewan. Adults are active from May through August, with a wingspan of 25–35 mm. The species was first described by Francis Walker in 1863 and ranges across the continent from Alaska to the Atlantic coast.
Choristoneura fumiferana
eastern spruce budworm, spruce budworm
Choristoneura fumiferana, the eastern spruce budworm, is a tortricid moth native to eastern North America and the most destructive forest insect in the region's spruce-fir forests. The species exhibits dramatic population oscillations with outbreaks occurring approximately every 30–40 years, during which larvae defoliate millions of hectares of host trees. These cycles have been documented since at least the 16th century through tree-ring studies. The species serves as a critical food source for specialized avian predators during outbreak phases and has been the subject of extensive research into population dynamics and forest pest management.
Choristoneura lambertiana
sugar pine tortrix, sugar pine tortrix moth
Choristoneura lambertiana, commonly known as the sugar pine tortrix, is a tortricid moth native to western North America. The species exhibits pronounced host-specific variation across its range, with three recognized subspecies each associated with different pine hosts: C. l. lambertiana on sugar pine (Pinus lambertiana), C. l. ponderosana on ponderosa pine (P. ponderosa) and limber pine (P. flexilis), and C. l. subretiniana on lodgepole pine (P. contorta) and Jeffrey pine (P. jeffreyi). Populations have been documented as outbreak defoliators of lodgepole pine in Idaho and Montana during the mid-to-late 1960s.
Choristoneura pinus
jack pine budworm, Jack Pine Budworm Moth
Choristoneura pinus, the jack pine budworm, is a tortricid moth native to North American jack pine forests. First described by Freeman in 1953, this species undergoes periodic population outbreaks that defoliate Pinus banksiana stands across Canada and the northern United States. Larval survival depends critically on the availability of pollen cones during spring dispersal. The species exhibits lagged density-dependent dynamics with its host tree, contributing to outbreak cycles of 6–12 year intervals.
Choristoneura retiniana
Modoc budworm
Choristoneura retiniana is a conifer-feeding tortricid moth known as the Modoc budworm. It occurs in California, Nevada, and Oregon, where it feeds primarily on true firs (Abies spp.), particularly white fir. The species is sympatric with the western spruce budworm (C. occidentalis) in mixed conifer stands, and the two species hybridize in nature. Larvae are characteristically green, distinguishing them from the brown larvae of C. occidentalis. The species exhibits density-dependent parasitoid complexes that may serve as indicators of population trends.
Chrysodeixis
Chrysodeixis is a genus of owlet moths (family Noctuidae, subfamily Plusiinae) described by Jacob Hübner in 1821. The genus contains approximately 30 described species distributed across the Americas, Asia, and Oceania. Several species are significant agricultural pests, particularly Chrysodeixis includens (soybean looper) and C. chalcites (tomato looper), which cause defoliation damage to legume and solanaceous crops. Larvae are characterized by having three pairs of prolegs and a distinctive looping locomotion.
Cimbex
Elm sawflies, Birch sawflies, Almond leaf wasps
Cimbex is a genus of large, robust sawflies in the family Cimbicidae, distributed across North America, Europe, and Asia. Adults are among the largest sawflies, with body lengths reaching 20-25 mm, and are frequently mistaken for bees or wasps due to their plump appearance and yellow-and-black coloration. The genus includes notable species such as C. americanus (elm sawfly), C. femoratus (birch sawfly), and C. quadrimaculatus (almond leaf wasp), some of which are significant defoliators of trees. Larvae are caterpillar-like, with seven pairs of prolegs distinguishing them from lepidopteran caterpillars, and possess chemical defense glands. The genus has a fossil record extending from the Eocene to the Miocene.
Cladius pectinicornis
bristly rose sawfly
Cladius pectinicornis is a Palearctic sawfly whose larvae are known as bristly rose slugs, significant pests of cultivated roses. The small wasp-like adults exhibit striking sexual dimorphism in antennae structure, with males bearing pectinate (comb-like) antennae. Larvae skeletonize rose leaves by feeding on tissue between vascular bundles, and can cause severe defoliation when abundant. The species has been introduced to North America, where it occurs on both coasts and ranges from Nova Scotia to British Columbia.
Cleora
Cleora is a genus of geometrid moths erected by John Curtis in 1825. The genus contains approximately 50 described species distributed across multiple continents. Some species, such as Cleora cornaria (the neem looper), are economically significant as defoliators of cultivated trees. The genus includes species with varied common names reflecting their appearance or host associations, including the ringed carpet (C. cinctaria), projected gray (C. projecta), double-lined gray (C. sublunaria), and kawakawa looper (C. scriptaria).
Clostera
Clostera is a genus of moths in the family Notodontidae, subfamily Pygaerinae, containing approximately 30 described species distributed across the Holarctic and Oriental regions. Multiple species, including C. anachoreta, C. anastomosis, C. fulgurita, and C. cupreata, are recognized as significant defoliators of poplar (Populus) trees in forestry contexts across China, India, Europe, and Japan. The genus has been extensively studied for its economic impact and as a target for biological control and Bt toxin research.
Coloradia pandora
Pandora Pinemoth, Pandora Moth
Coloradia pandora is a large saturniid moth native to western North America. The larvae are specialized feeders on pine foliage, with documented hosts including lodgepole pine, Jeffrey pine, and ponderosa pine. Outbreak populations occasionally cause severe defoliation in coniferous forests of northern Arizona, central Oregon, and southern California. The species has historical significance for indigenous peoples; the Paiute traditionally harvested larvae as a food source. Adults are nocturnal and do not feed.
Condylorrhiza vestigialis
Alamo Moth, Brazilian Poplar Moth
A crambid moth native to the Americas, known as the Alamo Moth or Brazilian Poplar Moth. Larvae are specialized feeders on Populus species, making this species a significant pest of poplar and cottonwood plantations in Brazil. Adults exhibit well-documented calling behavior, with virgin females releasing sex pheromones during specific nighttime hours to attract males. The species has been extensively studied for biological control applications, particularly for baculovirus production.
Cydalima perspectalis
box tree moth, box tree caterpillar
Cydalima perspectalis, commonly known as the box tree moth, is a highly invasive pest moth native to East Asia. First described in 1859, it has spread rapidly across Europe since 2006 and was detected in North America in 2018. The species is a specialist herbivore of boxwood (Buxus spp.), with larvae capable of causing severe defoliation and plant mortality. Multiple generations per year and efficient dispersal via horticultural trade have facilitated its global expansion.
Dasychira pinicola
pine tussock moth, pine tussock
Dasychira pinicola, the pine tussock moth, is a North American species in the tussock moth subfamily Lymantriinae. First described by Harrison Gray Dyar Jr. in 1911, it is associated with pine forests in the eastern and upper midwestern United States. The species is recognized as a defoliator of Pinus species, with larvae feeding on jack pine (Pinus banksiana) and potentially other conifers.
Datana
Datana is a genus of prominent moths in the family Notodontidae, erected by Francis Walker in 1855. The genus comprises approximately 13 described species distributed across North America. Larvae of Datana species are known defoliators of hardwood trees and are among the common late-season defoliators of southern U.S. forests. Several species are notable agricultural and ornamental pests, particularly on pecan and walnut trees.
Datana angusii
Angus' Datana Moth, Angus's datana moth
Datana angusii is a species of prominent moth in the family Notodontidae, described by Grote and Robinson in 1866. It occurs in North America, with records from the United States including Vermont. The species is part of a genus whose larvae are known as significant defoliators of hardwood trees. The MONA (Hodges) number for this species is 7903.
Datana contracta
Contracted Datana Moth
Datana contracta, commonly known as the contracted datana, is a moth species in the family Notodontidae. It is native to eastern and central North America, ranging from Maine to Florida and westward to Arkansas and Wisconsin. The species has a wingspan of 35–50 mm. Larvae feed on foliage of various woody plants including blueberries, hickories, oaks, sycamore, and witch-hazel.