Defoliator
Guides
Phryganidia
California Oak Moth
Phryganidia is a genus of prominent moths in the family Notodontidae, containing three species found in western North America. The genus is best known for Phryganidia californica, commonly called the California Oak Moth or California Oakworm, which undergoes periodic population outbreaks that can cause extensive defoliation of oak trees along the California coast. The genus was formerly placed in its own family, Dioptidae, but has been reclassified into Notodontidae. Adults are dull brown with weak flight, while larvae are specialized feeders on oak foliage.
Phryganidia californica
California Oak Moth, California Oakworm
Phryganidia californica, commonly known as the California oak moth or California oakworm, is a moth in the family Notodontidae. It is the only member of its subfamily Dioptinae found north of Mexico. The species is notable for periodic population outbreaks that can cause extensive defoliation of oak trees along the California coast. Adults are active from March to November, with two generations per year in northern California and occasionally three in southern California.
Phyllophaga anxia
Forest-ogre June Beetle, Cranberry White Grub, Common June Beetle
Phyllophaga anxia is a large scarab beetle native to North America, commonly known as the forest-ogre June beetle or cranberry white grub. Adults are nocturnal fliers active primarily in May and June, with males attracted to light during pre-copulatory flights. The species is a significant agricultural pest, with larvae feeding on roots of various host plants and adults feeding on foliage. It serves as host for multiple parasitoids including the American pelecinid wasp Pelecinus polyturator and several mite species.
Pinyonia edulicola
Pinyon Spindle Gall Midge, Pinyon Spindlegall Midge
A tiny gall-forming midge in the family Cecidomyiidae that induces spindle-shaped galls on developing pinyon pine needles. Adult emergence occurs in mid-June to mid-July. Heavy infestations cause premature needle drop and substantial defoliation, making it a pest of concern in urban landscapes of Colorado.
Plagodis phlogosaria
scorched wing, straight-lined plagodis, Straight-lined Plagodis Moth
Plagodis phlogosaria is a geometrid moth widely distributed across North America. Adults have a wingspan of 28–38 mm and are active from April to August. Larvae feed on the foliage of several deciduous trees and shrubs. The species is recognized by six described subspecies with varying geographic ranges.
Plusiina
Plusiina is a subtribe within the subfamily Plusiinae of the moth family Noctuidae. Members are commonly known as loopers or semiloopers due to their distinctive larval locomotion. The subtribe includes economically significant agricultural pests such as Rachiplusia nu and Chrysodeixis includens, which cause defoliation damage to soybean and other crops. Larvae are characterized by having three pairs of prolegs and a looping gait, distinguishing them from true geometrid loopers which possess only two pairs.
Plusiinae
Plusiine Looper Moths, Looper Moths
Plusiinae is a subfamily of moths within Noctuidae, commonly known as plusiine looper moths. The group is characterized by larvae with three pairs of prolegs that move with a distinctive looping gait. Several species are significant agricultural pests, particularly of soybean and other legumes. The subfamily is relatively small compared to other noctuid groups, and its taxonomic status may be elevated to family rank pending resolution of Noctuidae paraphyly.
Pococera robustella
pine webworm moth
Pococera robustella, commonly known as the pine webworm moth, is a species of pyralid moth whose larvae are significant defoliators of pine trees in eastern North America. The caterpillars feed on pine needles and produce characteristic webbing, giving rise to the common name. This species has been documented as prey for the assassin bug Acholla multispinosa.
Pristiphora
Pristiphora is a genus of sawflies in the family Tenthredinidae. Species within this genus are known for their larval feeding on leaves of various plants, with some species causing significant economic damage to trees and shrubs. The genus includes notable pests such as the larch sawfly (Pristiphora erichsonii), which defoliates tamarack and other larch species. Adults are small, dark-colored wasp-like insects with two pairs of wings.
Pristiphora erichsonii
Larch Sawfly
Pristiphora erichsonii, commonly known as the larch sawfly, is a species of sawfly native to Europe that was introduced to North America in the mid-to-late 19th century. It is a significant defoliator of larch trees (Larix spp.), particularly tamarack (Larix laricina) in North America. The species undergoes population outbreaks that can cause severe defoliation, though trees typically recover from single-year damage. Severe defoliation over multiple years can weaken trees and reduce winter survival. The species has been the subject of extensive ecological and population dynamics research due to its economic importance in forestry.
Pristiphora rufipes
columbine sawfly
Pristiphora rufipes, commonly known as the columbine sawfly, is a non-native sawfly species native to central Europe that was first discovered in North America in Canada in 1963. It has since spread across the eastern seaboard to the Rocky Mountains, becoming a significant pest of columbine plants (Aquilegia spp.). Adult females use a saw-like ovipositor to insert eggs into leaf tissue, and the caterpillar-like larvae feed on columbine foliage, capable of completely defoliating plants. The species exhibits multiple generations per year in warmer regions, with two generations common in the mid-Atlantic and three or more in England.
Pristiphora serrula
Pristiphora serrula is a species of sawfly in the family Tenthredinidae, subfamily Nematinae. As a member of the genus Pristiphora, it belongs to a group of sawflies commonly associated with feeding on various woody plants. The genus Pristiphora includes numerous species that are significant defoliators of trees and shrubs, with larvae typically feeding externally on leaves. Specific biological details for P. serrula are limited in the available literature.
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.
Pseudexentera oregonana
aspen leafroller
Pseudexentera oregonana is a tortricid moth commonly known as the aspen leafroller. It is recognized as an economic defoliator of aspen (Populus). The female sex pheromone has been chemically characterized, with Z8-14:Ac identified as the principal attractive component. The species exhibits reproductive isolation through species-specific pheromone communication.
Pseudexentera spoliana
bare-patched leafroller moth
Pseudexentera spoliana, commonly known as the bare-patched leafroller moth, is a tortricid moth species found in eastern North America. The species is an economically important defoliator of oak trees (Quercus spp.), with larvae feeding on oak foliage. Adult moths are small, with a wingspan of approximately 19 mm. Mating is mediated by a species-specific sex pheromone system, with males attracted to (Z)-10-hexadecenyl acetate (Z10-16:Ac).
Pyrrhalta viburni
Viburnum leaf beetle
Pyrrhalta viburni, the viburnum leaf beetle, is a Eurasian leaf beetle (Chrysomelidae) that has become a significant invasive pest in North America. Native to Europe and Asia, it was first detected in Canada in 1947 and spread to the northeastern United States by 1996. The beetle is a specialist herbivore of Viburnum shrubs, with both larvae and adults feeding on foliage. Severe infestations can completely defoliate host plants, leading to plant decline or death. The species exhibits distinctive aggregative oviposition behavior, with females preferentially laying eggs on twigs already containing conspecific egg masses.
Sabulodes
Sabulodes is a genus of geometrid moths (Geometridae: Ennominae) first described by Achille Guenée in 1857. The genus contains approximately 50 described species distributed primarily in the Americas, with some species occurring in the Neotropics. Several species have been documented as forest defoliators, including Sabulodes glaucularia, which has been reported as a pest of Pinus patula, Cupressus lusitanica, and Eucalyptus in Colombian forests. The genus is taxonomically well-established but individual species-level biology remains incompletely documented.
Spodoptera eridania
Southern Armyworm Moth, Southern Armyworm
Spodoptera eridania is a highly polyphagous noctuid moth whose larvae are significant agricultural pests in tropical and subtropical regions of the Western Hemisphere. The species has emerged as one of the most important armyworm pests of soybean in Brazil and Argentina, particularly in cotton-growing regions, while remaining a sporadic pest in the southern United States. Larvae feed gregariously when young, skeletonizing leaves, and become solitary as they mature, often boring into fruit. The species has been introduced to West Africa (Nigeria and Cameroon).
Strepsicrates
Strepsicrates is a genus of tortricid moths in the subfamily Olethreutinae, tribe Eucosmini, established by Meyrick in 1888. Species within this genus are distributed across multiple continents including Asia, Australia, the Americas, and Africa. Several species are economically significant as pests of forestry and agricultural crops, particularly those feeding on Eucalyptus, Cordia, and Myrica species. The genus has undergone taxonomic revision, with some species historically transferred between Strepsicrates and the related genus Stictea.
Symmerista
Symmerista is a genus of prominent moths (family Notodontidae) erected by Jacob Hübner in 1821. The genus contains at least nine described species distributed primarily in North America, with several species described from Central America. Larvae are notable for a distinctive leaf-clipping behavior where they sever petioles after feeding and apply red saliva to the cut surface, a trait that has been experimentally demonstrated to introduce salivary constituents into the plant's vascular system to suppress defense responses in nearby leaves.
Symmerista leucitys
orange-humped mapleworm moth, orange-humped mapleworm
Symmerista leucitys is a notodontid moth commonly known as the orange-humped mapleworm moth. The species is a univoltine specialist defoliator of sugar maple, with a single generation per year. Larvae exhibit distinctive leaf-clipping behavior, severing petioles after feeding and applying red saliva containing pigments from the anterior labial glands to the petiole stub. This saliva travels rapidly into the petiole xylem and is hypothesized to suppress plant defense responses in nearby leaves. During outbreak years, clipped leaves can comprise over 80% of greenfall losses in early October.
Systena frontalis
red-headed flea beetle, Red-headed Systena
Systena frontalis, commonly known as the red-headed flea beetle, is a flea beetle species in the family Chrysomelidae native to North America. It has become a significant economic pest of ornamental plant nurseries across the central and eastern United States, particularly affecting container-grown plants. Adults feed on foliage, creating shotholes and skeletonization that reduce plant salability. The species has expanded its pest status to cranberry production systems and shows a broad host range encompassing numerous woody ornamental species. Its biology includes holometabolous development with four larval instars, and it overwinters as eggs in growing medium or soil.
Tenthredinini
Tenthredinini is a tribe of sawflies within the family Tenthredinidae, characterized by medium to large body size and often vivid coloration. The tribe includes the genus Tenthredo, one of the most species-rich and well-known sawfly genera. Members are herbivorous as larvae, with many species feeding on diverse host plants. Adults are frequently observed visiting flowers for nectar and pollen.
Tenthredo grandis
Tenthredo grandis is a sawfly species in the family Tenthredinidae. Unlike typical wasps, sawflies lack a narrow "wasp waist," with the abdomen broadly attached to the thorax. The larvae are herbivorous rather than carnivorous, feeding on turtlehead plants (Chelone spp.) during midsummer. Adults are often observed on flowers and consume smaller insects as well as pollen and nectar. The species exhibits mimicry of stinging wasps despite females lacking a functional stinger.
Thyrinteina arnobia
eucalyptus brown looper, brown looper caterpillar
Thyrinteina arnobia is a geometrid moth native to the Americas and a major pest of Eucalyptus plantations in Brazil. The species occurs throughout South America and parts of Central and North America, where it feeds primarily on Myrtaceae, with Eucalyptus serving as a vulnerable host in commercial plantations. Larval infestations can reduce annual Eucalyptus biomass production by up to 40%, making it the primary defoliator of subtropical and tropical Brazilian eucalyptus farms. Population genetic studies indicate low genetic diversity in Brazil with three regional mitochondrial haplogroups, suggesting outbreaks arise from local populations rather than long-distance dispersal.
Tolype
Tolype Moths
Tolype is a genus of moths in the family Lasiocampidae, subfamily Poecilocampinae, established by Jacob Hübner in 1820. Species within this genus are known for caterpillars bearing urticating (stinging) hairs that can cause skin irritation in humans. At least one species, Tolype innocens, has been documented as a pest of blueberry crops in South America, where larvae feed on leaves and new shoots. The genus exhibits polyphagous feeding habits, with larvae consuming foliage from both forest plants and agricultural crops.
Tomostethus multicinctus
brownheaded ash sawfly
Tomostethus multicinctus, commonly known as the brownheaded ash sawfly, is a sawfly species in the family Tenthredinidae native to southern Canada and the eastern United States. Adults are wasp-like in appearance but do not sting. The larvae are specialized herbivores that feed gregariously on ash foliage, with a life cycle tightly synchronized with the leaf phenology of their host trees. Heavy infestations can cause complete defoliation within a week, though trees typically recover by producing new foliage.
Trachymela sloanei
Australian tortoise beetle, small eucalyptus tortoise beetle
Trachymela sloanei is a leaf beetle in the family Chrysomelidae, native to Australia where it feeds on Eucalyptus trees. The species has established invasive populations in multiple regions including California, Chile, Spain, Portugal, Greece, and China. It was first detected in Europe in 2014 and reported from Algeria in May 2025, representing the first African record. The beetle is recognized as a defoliating pest of Eucalyptus species with potential economic and ecological impacts in invaded regions.
Trichiocampus
Trichiocampus is a genus of sawflies in the family Tenthredinidae. The genus includes species associated with poplar trees (Populus spp.), with at least one species, T. viminalis, known to cause significant defoliation during population outbreaks. Members occur across a broad circumpolar distribution spanning Europe and northern North America.
Xanthogaleruca luteola
elm leaf beetle
Xanthogaleruca luteola, the elm leaf beetle, is an invasive leaf beetle native to Europe that has become the most serious defoliator of elm trees in North America. Adults are yellow to olive-green with distinctive black lateral stripes and spots. Both adults and larvae feed on elm foliage, with larvae skeletonizing leaves by consuming soft tissue between veins. The species has multiple generations annually, with larvae overwintering in soil or bark crevices. Biological control using introduced parasitoids has reduced its pest status in many regions.
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.
Zadiprion rohweri
Pinyon Pine Sawfly
Zadiprion rohweri, commonly known as the Pinyon Pine Sawfly, is a species of conifer-feeding sawfly in the family Diprionidae. It is associated with pinyon pine (Pinus edulis and related species) in the southwestern United States and Mexico. The species was described by Middleton in 1931 and is one of several Zadiprion species specialized on pine hosts. Sawflies in this genus are known for gregarious larval feeding that can cause noticeable defoliation.
Zygogramma exclamationis
sunflower beetle
Zygogramma exclamationis, the sunflower beetle, is a leaf-feeding chrysomelid beetle native to North America. Adults emerge from hibernation in late spring to early summer, coinciding with sunflower seedling emergence, and feed on young leaves. Larvae develop through summer, feeding nocturnally on foliage while hiding in flower bracts during daylight hours. The species completes one generation per year, with new adults emerging in late summer before overwintering in soil. It is a recognized pest of cultivated sunflowers, particularly damaging to seedlings, and serves as host for parasitoid tachinid flies including Myiopharus neilli.
Zygogramma signatipennis
Zygogramma signatipennis is a leaf beetle in the family Chrysomelidae found in Mexico. The species has been documented feeding on acahual plants (Tithonia tubaeformis, Asteraceae), causing moderate to severe defoliation damage specifically to this host. Research suggests it shows greater feeding preference for plants in the vegetative stage and has been proposed as a potential biological control agent for management of T. tubaeformis as a weed. The species was originally described by Stål in 1859.