Pest
Guides
Lorita scarificata
chrysanthemum flower borer
Lorita scarificata, commonly known as the chrysanthemum flower borer, is a small tortricid moth native to North America and introduced to Hawaii. The species was described by Meyrick in 1917 and is notable for its association with cultivated and wild flowering plants. Adults are diminutive with a wingspan of only 10–12 mm. The species has gained minor notoriety as a pest of ornamental chrysanthemums and agricultural crops.
Lyctinae
Powderpost beetles, Powder-post beetles
Lyctinae (powderpost beetles) is a subfamily of approximately 70 species of woodboring beetles within the family Bostrichidae. Members are distinguished by their reduced prothorax, which leaves the head more visible than in most woodboring beetles, and by antennal clubs with two segments. The subfamily includes three tribes—Lyctini, Trogoxylini, and Cephalotomini (the latter now synonymized with Trogoxylini)—and occurs worldwide. Some genera exhibit unusual ecological strategies, including the use of galleries created by other beetles rather than excavating their own.
Lyctoxylon
Lyctoxylon is a genus of powderpost beetles in the family Bostrichidae, subfamily Lyctinae. The genus was established by Reitter in 1878. Members are woodboring beetles that infest dry, seasoned hardwoods. Lyctoxylon dentatum, the type species, has been introduced to multiple continents beyond its native Asian range.
Lyctus
powderpost beetles, lyctid beetles
Lyctus is a genus of powderpost beetles in the family Bostrichidae. These beetles are wood-boring pests with a cosmopolitan distribution across all continents except Antarctica. The genus includes economically significant species that infest hardwood products.
Lyctus linearis
European lyctus beetle, powderpost beetle
Lyctus linearis is a wood-boring beetle in the family Bostrichidae, commonly known as the European lyctus beetle or a powderpost beetle. Originally native to tropical regions, it has established populations worldwide through human transport of wood products. It is a significant pest of hardwood timber and finished wood products, causing damage through larval feeding that reduces wood to a fine powder. The species shows particular association with deciduous tree woods.
Lygaeus
seed bugs, milkweed bugs
Lygaeus is a genus of seed bugs in the family Lygaeidae, containing over 60 described species. Members are characterized by aposematic coloration—typically combinations of red, black, gray, and white—that advertises chemical defenses. Several species, notably L. kalmii (small milkweed bug), sequester cardiac glycosides from host plants, rendering them unpalatable to predators. The genus exhibits diverse feeding strategies ranging from seed-feeding specialization to opportunistic scavenging.
Lymire edwardsii
Edwards' Wasp Moth, rubber tree caterpillar
Lymire edwardsii is a moth in the family Erebidae (subfamily Arctiinae) described by Augustus Radcliffe Grote in 1881. The species is known for its caterpillars, which feed on Ficus species and frequently cause extensive injury to these trees, earning the common name 'rubber tree caterpillar.' Adults have a wingspan of 35–40 mm with bluish-gray wings and are active year-round in southern Florida.
Macalla
Macalla is a genus of pyralid moths in the subfamily Epipaschiinae, established by Walker in 1859. The genus includes species whose larvae are known to feed on mahogany (Swietenia) and related plants, with Macalla thyrsisalis (mahogany webworm) being the most documented species due to its economic importance as a pest of West Indies mahogany. Adult moths are nocturnal and attracted to light. The genus is part of the diverse snout moth family Pyralidae, which contains many economically significant agricultural and forestry pests.
Macrodactylus subspinosus
American Rose Chafer, Rose Chafer
Macrodactylus subspinosus, commonly known as the American Rose Chafer, is a scarab beetle native to North America. It is a significant agricultural and horticultural pest that feeds on the foliage, flowers, and fruit of numerous plants, including roses, grapes, apples, and peaches. Adults emerge in late May to mid-June, live 3–6 weeks, and aggregate on host plants using plant volatiles to locate feeding sites. The species undergoes complete metamorphosis with larvae overwintering deep in soil and feeding on plant roots.
Macronoctua onusta
iris borer, Iris Borer Moth
Macronoctua onusta, commonly called the iris borer, is a noctuid moth native to North America. Adults are large, dull brown moths with distinctive smoky dark gray patterning and a uniquely shaped reniform spot. The species is a foodplant specialist whose larvae bore into the rhizomes of iris plants, making it a notable pest in gardens and horticulture. Adults fly in autumn, primarily September and October.
Macrophya
Macrophya is a genus of sawflies in the family Tenthredinidae. The genus contains numerous species distributed across Europe, Asia, and North America, with particularly high diversity in China. Several species have been documented as pests of woody plants, including Macrophya satoi, which damages Japanese ash (Fraxinus japonica). The larvae of many species feed on foliage of trees and shrubs. Some species have had their genomes sequenced, including M. alboannulata and M. annulata.
Macropsis fuscula
Raspberry Leafhopper
Macropsis fuscula is a leafhopper species native to Europe, first recorded in North America in 1952 on Lulu Island, British Columbia, where it established as a pest of cultivated loganberry. The species exhibits population dynamics responsive to host availability and climatic events, having crashed after a severe freeze eliminated cultivated hosts in 1955, then rebounded within three years via re-infestation from wild host plants. It is now known from multiple localities across Europe and Asia, with 71 iNaturalist observations documenting its continued presence.
Macrosiphoniella sanborni
Chrysanthemum Aphid, Brown Chrysanthemum Aphid
Macrosiphoniella sanborni, the chrysanthemum aphid, is a phloem-feeding aphid in the family Aphididae. It is an oligophagous pest specialized on Chrysanthemum species and a major economic threat to chrysanthemum cultivation. The species exhibits wing dimorphism, with alate (winged) and apterous (wingless) morphs showing distinct chemosensory gene expression profiles. It vectors chrysanthemum viruses including vein mottle virus and virus B.
Magdalis
wedge-shaped bark weevils
Magdalis is a genus of wedge-shaped bark weevils in the family Curculionidae, containing at least 20 described species. Species within this genus are associated with woody host plants, including oaks and elms. At least one species, Magdalis armicollis, has been documented as a pest of red oak, causing twig dieback through larval tunneling. The genus has a broad distribution including North America and Eurasia.
Malacosoma californica
Western Tent Caterpillar Moth, Western Tent Caterpillar
Malacosoma californica, the western tent caterpillar, is a moth species in the family Lasiocampidae found in western North America. The larvae are social caterpillars that construct conspicuous silken tents in host trees and shrubs. They undergo cyclical population outbreaks and are significant defoliators of various woody plants. The species overwinters as eggs and completes one generation per year.
Manduca quinquemaculatus
Five-spotted Hawk Moth, Tomato Hornworm
Manduca quinquemaculatus, commonly known as the five-spotted hawk moth or tomato hornworm, is a large sphinx moth whose caterpillar is a significant agricultural pest. The adult moth has a wingspan up to 5 inches (12 cm) and is a strong flier active at night. The larval stage feeds primarily on tomatoes and other Solanaceae plants, causing extensive defoliation when populations are high. The species is closely related to and often confused with the tobacco hornworm (Manduca sexta).
Marginitermes hubbardi
light western drywood termite
Marginitermes hubbardi, commonly called the light western drywood termite, is a drywood termite species in the family Kalotermitidae. It is distinguished from the sympatric Incisitermes minor by its notably paler winged reproductives. The species is native to arid regions of southwestern North America and Central America, where it colonizes dry wood including living trees, dead cacti, and human structures. Unlike dampwood or subterranean termites, it does not require soil contact or high moisture levels to establish colonies.
Marmara elotella
Apple Barkminer
Marmara elotella, commonly known as the apple barkminer, is a microlepidopteran moth in the family Gracillariidae. The species is known from five eastern US states and is associated with apple and pear cultivation. Its larvae are specialized twig miners that feed as sap-feeders within host plant tissues.
Megacyllene robiniae
Locust Borer
Megacyllene robiniae, the locust borer, is a longhorn beetle endemic to eastern North America and a significant pest of black locust trees (Robinia pseudoacacia). Adults are active from late August through October, feeding on goldenrod pollen. The species exhibits striking black and yellow banding that mimics wasps. Larval tunneling in living black locust wood creates entry points for fungal pathogens, contributing to tree decline and wind damage susceptibility.
Megalographa biloba
Bilobed Looper Moth, Stephens' Gem
A noctuid moth in the subfamily Plusiinae with a wingspan of 38–44 mm. It occurs from the southern United States through Central and South America to Argentina, and migrates seasonally into northern United States and southern Canada where it produces one or two summer generations but rarely survives winter. The species is sometimes considered a pest on cultivated lettuce.
Melalgus plicatus
Groove-sided Bostrichid
Melalgus plicatus is a species of horned powder-post beetle in the family Bostrichidae. It occurs across the Americas from North America through Central America to South America. The species is characterized by grooved lateral sides, which gives rise to its common name. As a member of the Bostrichidae, it belongs to a family of wood-boring beetles often associated with dead or dying wood.
Melanaphis
sugarcane aphid
Melanaphis is a genus of aphids in the family Aphididae, first described by van der Goot in 1917. The genus includes species that are significant agricultural pests, particularly of sorghum and sugarcane. Melanaphis sacchari (sugarcane aphid) has become one of the most damaging insect pests of grain and forage sorghum in the United States since its first recorded occurrence on sorghum in Texas in 2013. Members of this genus are characterized by their parthenogenetic reproduction, rapid population growth, and production of honeydew.
Melanchra picta
Zebra Caterpillar Moth
Melanchra picta is a noctuid moth commonly known as the zebra caterpillar moth. The species is native to North America and is best known for its larval stage, which feeds on various cultivated plants including cabbages and beets. The moth belongs to the family Noctuidae, one of the largest families of moths, and is classified within the subfamily Noctuinae.
Melanchroia
white-tipped black moths, snowbush spanworms
Melanchroia is a genus of diurnal moths in the family Geometridae, subfamily Ennominae. The genus was established by Jakob Hübner in 1819 and contains eight described species distributed from the southeastern United States through the Neotropics to Argentina. Adults are notable for their striking black and white or black and red coloration, often mistaken for tiger moths or wasp-mimicking groups. The best-known species, M. chephise (white-tipped black or snowbush spanworm), is an occasional pest of ornamental plants whose gregarious larvae feed on Euphorbiaceae.
Melanocallis caryaefoliae
Black Pecan Aphid
Melanocallis caryaefoliae, commonly known as the black pecan aphid, is a specialized pest of pecan trees (Carya illinoinensis). Among aphid species attacking pecans, it produces the most severe foliar symptoms and achieves the highest mean density on susceptible cultivars. While feeding, it injects a toxin that causes bright yellow lesions between leaf veins, which subsequently turn brown and die. Premature defoliation from heavy infestations reduces nut fill and can diminish the following year's production. Unlike yellow pecan aphids, M. caryaefoliae is considered more destructive even at low densities, with economic thresholds as low as three aphids per compound leaf.
Melanoplus bivittatus
Two-striped grasshopper, Yellow-striped grasshopper
Melanoplus bivittatus, the two-striped grasshopper, is one of the largest and most economically significant grasshopper species in North America. It is a polyphagous mixed-feeder that prefers forbs over grasses but consumes both. The species is notable for its distinctive paired pale yellow stripes running along the dorsum from the eyes to the wing tips. It exhibits density-dependent morphological plasticity, with high-density populations developing longer wings and slimmer bodies more adapted to flight and migration.
Melanoplus bivittatus bivittatus
Two-striped grasshopper
The two-striped grasshopper is a large, robust species widely distributed across North America. It is a polyphagous mixed-feeder that consumes both grasses and forbs, with a documented preference for forbs when available. This subspecies has been historically recognized but is now generally treated as a synonym of the species Melanoplus bivittatus. It is considered one of the most economically important grasshopper pests in western North America, particularly in Colorado where it attacks cereals, alfalfa, garden vegetables, and ornamental plantings.
Melanoplus bruneri
Bruner's spur-throat grasshopper, Bruner's locust
Melanoplus bruneri is a medium-sized, fully winged spur-throated grasshopper native to North America. It inhabits diverse environments including arctic tundra, northern prairies, and mountain meadows, often reaching elevations above 10,000 feet. The species exhibits a two-year egg diapause in mountain habitats, though one-year development occurs under warmer low-altitude conditions. Outbreak populations have historically caused significant damage to rangeland forage across western North America.
Melanoplus differentialis
Differential Grasshopper
Melanoplus differentialis is a large, highly mobile grasshopper native to North America that has expanded from wet meadows into agricultural landscapes. It is a severe crop pest, particularly damaging to corn, alfalfa, soybeans, cotton, and small grains, with dense swarms capable of destroying young cornfields in three to four days. The species exhibits phase polymorphism, with crowded individuals developing darker pigmentation and different body proportions compared to isolated individuals. It has one generation annually and is better adapted to warmer climates than related species, with outbreaks concentrated in the central United States between the Rocky Mountains and Mississippi River.
Melanoplus rugglesi
Nevada Sage Grasshopper
Melanoplus rugglesi is a medium-sized spur-throated grasshopper endemic to the cold desert shrublands of the western United States. The species exhibits pronounced phase polyphenism, with solitary and migratory forms differing in body size, wing length, and coloration. Named in honor of entomologist Arthur G. Ruggles, this grasshopper is notable for its extreme migratory behavior and extended outbreak dynamics, with populations persisting at high densities for multiple years.
Melanoplus sanguinipes
migratory grasshopper, lesser migratory grasshopper, red-legged grasshopper
Melanoplus sanguinipes is a medium-sized spur-throated grasshopper and one of the most economically important grasshopper pests in North America. It is widely distributed across the continent, inhabiting diverse grassland habitats from native prairies to agricultural fields and disturbed areas. The species exhibits remarkable ecological flexibility, feeding on both grasses and forbs, and displays migratory behavior at high population densities. Under favorable conditions, populations can increase exponentially and form swarms that travel hundreds of miles, causing extensive damage to crops and rangeland. The species has been extensively studied for its population ecology, host plant relationships, and integrated pest management.
Melanotus communis
corn wireworm
Melanotus communis is a click beetle (Elateridae) whose larvae, known as corn wireworms, are significant agricultural pests in the eastern United States. Adults are reddish-brown and approximately 13 mm long. The species has been studied extensively for its pest status in sugarcane, potato, and other crops, with research focusing on entomopathogen susceptibility, pheromone-based monitoring, and soil habitat preferences.
Melanotus insipiens
Melanotus insipiens is a small click beetle (Elateridae) native to the eastern United States. Its female-produced sex pheromone has been identified as decyl butanoate, enabling pheromone-based monitoring of this species. Adults are active above ground primarily in May and June, while immature stages are soil-dwelling. The species has been recorded as a pest of alsike clover and wheat in Georgia.
Melanotus similis
Melanotus similis is a species of click beetle in the family Elateridae, described by Kirby in 1837. It is a soil-inhabiting pest of row crops that has also been documented in forest habitats. The species occurs in eastern Canada, with records from Manitoba, New Brunswick, Nova Scotia, Ontario, and Prince Edward Island.
Merhynchites
Rose Weevils
Merhynchites is a genus of leaf and bud weevils in the family Attelabidae, containing approximately 12 described species. The genus includes the well-known rose curculio (Merhynchites bicolor), a significant pest of cultivated roses. Members of this genus are characterized by their elongated rostrums and association with flowering plants, particularly roses.
Meromyza americana
Wheat Stem Maggot
Meromyza americana, commonly known as the Wheat Stem Maggot, is a chloropid fly species whose larvae are significant pests of small grain cereals. The species completes a second generation in spring, with adults emerging to lay eggs on barley, oats, rye, wheat, and other grass hosts. Larval feeding occurs within stems, causing characteristic whitehead symptoms in infested tillers. Despite its pest status, infestations rarely exceed 1% of tillers, making insecticide treatments generally unnecessary.
Metachroma viticola
Metachroma viticola is a small leaf beetle in the family Chrysomelidae, measuring 4.0–5.8 mm in length. The species was described by Linell in 1898 and is named for its association with grapevines. It is known from the Gulf Coast region of the United States and Mexico.
Metamasius callizona
Mexican bromeliad weevil
Metamasius callizona is an invasive weevil native to southern Mexico, Guatemala, and Panama that was first documented in Florida in 1989. Adult females chew slits in bromeliad leaves near feeding sites and deposit single eggs within these wounds. Larvae mine meristematic tissue and flower stalks, typically killing host plants, while adult leaf feeding is generally non-fatal. Florida populations have grown dramatically larger than native-range densities and now threaten multiple native and endangered bromeliad species.
invasive-speciespestbiological-controlbromeliad-specialistFloridaMexicoGuatemalaPanamaTillandsiaAnanasLixadmontia-frankiholometabolousmultivoltineepiphyteconservation-concernendangered-species-threatgardening-industry-vectorparasitoid-introductionBeauveria-bassiana-(native-range-pathogen-not-present-in-Florida)Metamasius hemipterus
Silky Cane Weevil, West Indian Sugarcane Weevil, moleque-da-bananeira, broca-rajada
Metamasius hemipterus is a weevil species in the family Dryophthoridae, commonly known as the silky cane weevil or West Indian sugarcane weevil. It is a significant agricultural pest of sugarcane, banana, coconut, and ornamental palms. The species has been introduced to multiple regions beyond its native range and is now established across the Americas, Africa, and Oceania. Larvae bore into plant stalks and stems, causing direct and indirect damage that reduces crop productivity. The species is known to use aggregation pheromones and is associated with the endosymbiont "Candidatus Nardonella dryophthoridicola".
Metamasius hemipterus sericeus
silky cane weevil, West Indian sugarcane weevil
Metamasius hemipterus sericeus, commonly known as the silky cane weevil or West Indian sugarcane weevil, is a subspecies of weevil in the family Curculionidae. It is a significant agricultural pest of sugarcane and ornamental palms, particularly in tropical and subtropical regions. The species is notable for its male-produced aggregation pheromones, which attract both sexes and are synergized by host plant volatiles. Management is challenging due to the cryptic habitat of boring larvae and high reproductive potential.
Microtheca ochroloma
Yellow-margined Leaf Beetle, Yellowmargined Leaf Beetle
Microtheca ochroloma is a leaf beetle in the family Chrysomelidae, native to South America and adventive in North America. It is a significant agricultural pest of cruciferous crops, with documented populations in the southeastern United States. Development from egg to adult takes approximately 17–57 days depending on temperature, with optimal survival around 20–25°C. The species exhibits strong host preferences, favoring turnip and mustard while showing least preference for collard and cabbage.
Mindarus abietinus
Balsam Twig Aphid, Fir Shoot Aphid
Mindarus abietinus is an economically significant pest of fir Christmas trees, particularly in commercial plantations of Fraser fir (Abies fraseri) and balsam fir (Abies balsamea). The aphid causes leaf curling and shoot stunting of new foliage, reducing aesthetic quality and marketability despite having minimal impact on tree health and vigor. Temperature influences colony growth rates, with warmer conditions in late spring and early summer favoring higher population densities. The species has a holocyclic life cycle with precise seasonal timing tied to host phenology.
Minthea
tropical powderpost beetles
Minthea is a genus of tropical powderpost beetles in the family Bostrichidae, established by Pascoe in 1863. The genus comprises approximately eight described species distributed in tropical regions. Members of this genus are wood-boring beetles that infest dry wood, contributing to their classification as powderpost beetles alongside related genera in the subfamily Lyctinae.
Mirinae
plant bugs
Mirinae is a subfamily of plant bugs within the family Miridae, comprising seven recognized tribes: Herdoniini, Hyalopeplini, Mecistoscelini, Mirini, Restheniini, Scutelliferini, and Stenodemini. Members are phytophagous true bugs with piercing-sucking mouthparts. The subfamily includes economically significant species such as the fourlined plant bug (Poecilocapsus lineatus), which causes characteristic necrotic leaf damage on numerous ornamental and agricultural plants. Some species have been introduced to new regions, including New Zealand, where they have established non-native populations.
Molytinae
Molytinae is a large and diverse subfamily of weevils (Curculionidae) described by Carl Johan Schönherr in 1823. The subfamily contains numerous tribes and genera distributed worldwide, with particularly high diversity in tropical and subtropical regions. Many Molytinae species are associated with specific host plants, including conifers, oaks, and various flowering plants. Some species are economically important as pests of forestry and agricultural crops, while others are restricted to specialized habitats such as leaf litter, caves, or high-elevation ecosystems. The subfamily has undergone significant taxonomic revision in recent decades, with many new species described particularly from Central America, Africa, and Asia.
Monarthropalpus
boxwood leafminer gall midge
Monarthropalpus is a genus of gall midges in the family Cecidomyiidae. The genus contains at least one described species, M. flavus, commonly known as the boxwood leafminer. These small flies are native to Europe and were introduced to North America, where they have become significant pests of boxwood (Buxus spp.) ornamental plants. The larvae develop as leafminers within boxwood leaves, causing characteristic yellow-orange discoloration, blistering, and gall formation that disfigures foliage.
Monarthropalpus flavus
boxwood leafminer
A small gnat-like gall midge (Diptera: Cecidomyiidae) native to Europe that is a significant pest of boxwood (Buxus spp.) in ornamental landscapes. Adults are delicate orange flies resembling mosquitoes. Females use a drill-like ovipositor to insert eggs into the undersides of young leaves. Larvae feed gregariously within leaf tissue, inducing rudimentary blister galls through hypertrophy and hyperplasia of spongy parenchyma. The species represents an evolutionary intermediate between leafminers and true gall inducers. First detected in the United States in 1910, it now causes serious damage to boxwood across the eastern U.S.
Monarthrum mali
apple wood stainer
Monarthrum mali, commonly known as the apple wood stainer, is a bark beetle species in the family Curculionidae. It is recognized as a pest of apple trees, where it causes distinctive staining of wood tissue. The species has been documented in North America, including Canada and the Caribbean region.
Monelliopsis pecanis
Yellow Pecan Aphid
Monelliopsis pecanis, commonly known as the yellow pecan aphid, is a sap-feeding insect in the family Aphididae that specializes on pecan (Carya illinoinensis). It is one of two primary 'yellow' or 'honeydew' aphid species affecting pecan production, distinguished from the blackmargined aphid (Monellia caryella) by its roof-like wing posture and lack of a black marginal stripe on the wings. Outbreaks typically occur later in the growing season than those of M. caryella and can cause significant defoliation, reduced nut yield, and quality degradation. The species reproduces parthenogenetically during spring and summer, with sexual forms appearing in autumn to produce overwintering eggs.
Monema flavescens
Oriental moth
Monema flavescens is a medium-sized moth in the family Limacodidae (slug moths or cup moths), native to East Asia. Adults exhibit yellowish coloration typical of the genus, with males having a wingspan of 30–32 mm and females 35–39 mm. The larvae are polyphagous defoliators of broadleaf trees, bearing urticating spines that can affect human health. The species has one to two generations per year depending on region, with adults active from late June to August. It has been introduced to Massachusetts, USA, and is considered a potential quarantine pest for Europe.