Invasive
Guides
Scantius aegyptius
Mediterranean red bug
Scantius aegyptius, commonly known as the Mediterranean red bug, is a ground-dwelling true bug in the family Pyrrhocoridae. It is recognized by its striking red and black aposematic coloration. The species is native to the Mediterranean region and has established invasive populations in North America, particularly in California since 2009. It feeds primarily on seeds and seed pods of plants in the family Malvaceae.
Schistocerca nitens
vagrant grasshopper, gray bird grasshopper
Schistocerca nitens is a large grasshopper native to southern North America, closely related to the desert locust (Schistocerca gregaria). Adults are sexually dimorphic in size, with females reaching 60–70 mm and males 40–50 mm. The species exhibits mottled gray, brown, and yellow coloration with a distinctive stripe running from head to thorax. Unlike true locusts, it does not undergo phase polymorphism, though dense populations can occur through favorable conditions rather than behavioral transformation. The species has become invasive in Hawaii, where it caused severe vegetation damage on Nīhoa in 2004.
Schizaphis
Grass Aphids, Greenbug
Schizaphis is a genus of aphids in the family Aphididae, superfamily Aphidoidea. Originally distributed in the Palaearctic region, several species have been introduced worldwide. The genus contains more than 40 recognized species, with Schizaphis graminum (greenbug) being the most economically significant. Species in this genus are primarily associated with grasses and cereal crops, exhibiting varying degrees of host specificity from monophagy to polyphagy.
Scolytus mali
larger shothole borer, apple bark beetle, large fruit bark beetle
Scolytus mali is a bark beetle native to Europe that has become invasive in North America. It is commonly known as the larger shothole borer or apple bark beetle, reflecting its association with fruit trees. The species exhibits brief maturation feeding on living but weakened apple trees before aggregating for breeding in response to female-produced pheromones. Both sexes possess a well-developed gular-prosternal stridulatory apparatus and produce characteristic double chirps through head movement, with distinct acoustic differences between stress and attraction signals.
Scrobipalpa atriplicella
goosefoot groundling moth
Scrobipalpa atriplicella is a small gelechiid moth native to Eurasia, now established as an introduced species in North America. Adults have a wingspan of 10–14 mm and exhibit two generations per year. The species has emerged as a significant agricultural pest on quinoa (Chenopodium quinoa) in both Europe and North America, where larval feeding on seeds and foliage can cause complete crop loss. Originally associated with wild Chenopodiaceae including Chenopodium album and Atriplex species, its host range has expanded to include cultivated crops.
Scutigera coleoptrata
House Centipede, Thousand-legger
Scutigera coleoptrata, commonly known as the house centipede, is a fast-moving predatory centipede native to the Mediterranean region that has become cosmopolitan through human commerce. Adults possess 15 pairs of extremely long, delicate legs and well-developed faceted eyes—unusual traits among centipedes. They are synanthropic, thriving in human dwellings where they hunt household arthropods. Despite their alarming appearance and speed, they pose minimal threat to humans and are considered beneficial predators of pests.
Scyphophorus
agave weevils, sisal weevils
Scyphophorus is a genus of snout and bark beetles in the subfamily Dryophthorinae, comprising approximately seven described species. The genus is best known for Scyphophorus acupunctatus, commonly called the agave weevil or sisal weevil, which is a major pest of agave crops worldwide. Species in this genus are native to the Americas but have been introduced to multiple continents through global plant trade. The genus is characterized by its association with plants in the families Asparagaceae (Agavoideae) and Asparagaceae (Nolinoideae, formerly Dracaenaceae).
Scyphophorus acupunctatus
agave weevil, sisal weevil, picudo del agave
Scyphophorus acupunctatus is a specialized weevil native to Central and North America that has become a globally significant pest of agaves and related plants. Adults bore into agave stalks and rosettes, creating entry points for pathogenic bacteria and fungi that ultimately kill the host plant. The species has established invasive populations across Europe, Africa, Asia, Oceania, and South America, facilitated by the international trade of ornamental agaves. Its economic impact is particularly severe on Agave tequilana, threatening the tequila industry, and on wild agave populations important for mezcal production and ecosystem stability.
Singhiella
ficus whitefly
Singhiella is a genus of whiteflies (Hemiptera: Aleyrodidae) containing species that are significant pests of Ficus plants. The most economically important species, Singhiella simplex (the ficus whitefly), has become invasive across multiple continents, causing severe defoliation of ornamental Ficus hedges and trees. The genus is distinguished by puparial characteristics used in whitefly taxonomy, including color, shape, and wax placement.
Sinoxylon anale
horned powder-post beetle, auger beetle
Sinoxylon anale is a wood-boring beetle in the family Bostrichidae, commonly known as horned powder-post beetles or auger beetles. The species has a broad intercontinental distribution spanning Australia, North America, Southern Asia, and Europe. It develops in dead or dying woody material and has been recorded as a pest in agricultural and nursery settings. Recent studies have documented its establishment in Brazil and first record in Greece, with expanding host associations including allspice, jabuticaba, and various native and exotic woody plants.
Sitobion avenae
English Grain Aphid
Sitobion avenae, the English grain aphid, is a globally distributed pest of cereal crops. It feeds on phloem sap and transmits yellow dwarf viruses to wheat, barley, and oats. Population dynamics are influenced by temperature, water availability, and host plant quality. The species exhibits complex reproductive strategies including both cyclical and obligate parthenogenesis. Management challenges include insecticide resistance, variable biotypes, and climate change impacts on dispersal and adaptation.
Sitochroa palealis
carrot seed moth
Sitochroa palealis, known as the carrot seed moth, is a crambid moth native to Europe that was first reported in the United States in 2002. The species has a wingspan of 26–34 mm and is active during summer months. Its larvae specialize on umbelliferous plants, including cultivated carrot and fennel.
Sophonia
Sophonia is a genus of leafhoppers in the family Cicadellidae, subfamily Evacanthinae. Species in this genus are native to Asia and have been introduced to multiple regions including Hawaii, the continental United States, and Europe. At least one species, Sophonia rufofascia, has become an established pest in Hawaii since its detection in 1987. The genus is characterized by features typical of the Evacanthinae subfamily.
Sophonia orientalis
Two-spotted Leafhopper
Sophonia orientalis is a leafhopper species in the family Cicadellidae, commonly known as the Two-spotted Leafhopper. It is polyphagous and has established populations across Asia, Europe, the United States, and Oceania. The species is notable for its broad geographic distribution spanning multiple continents.
Spanioneura fonscolombii
Spanioneura fonscolombii is a plant-parasitic psyllid specialized on box (Buxus) species. First described from Europe in 1848, it has been accidentally introduced to the United States and represents a pest of ornamental and native boxwoods. The species shows distinctive green coloration with patterned wings and has been documented causing damage to host plants, with some dispute regarding gall formation.
Stator limbatus
Stator limbatus is a leaf beetle in the family Chrysomelidae, native to the southwestern United States, Mexico, and northern South America. It has established populations in multiple regions outside its native range, including Hawaii, South Africa, the Middle East, and Mediterranean islands. The species occupies xeric and semi-arid environments and has been documented feeding on legume seeds.
Steatoda bipunctata
Rabbit Hutch Spider
Steatoda bipunctata is a small cobweb spider in the family Theridiidae, commonly known as the Rabbit Hutch Spider due to its frequent association with human structures. Native to Europe, it has been introduced to North America and is now established across the Atlantic provinces, northern New England, and southern Québec and Ontario. It closely resembles the native North American species Steatoda borealis and has been documented to competitively displace it in disturbed habitats. The species poses minimal medical risk to humans.
Stephanitis
lace bugs
Stephanitis is a genus of lace bugs (family Tingidae) comprising at least 80–90 described species. Members are small, plant-feeding true bugs characterized by reticulated, lace-like forewings. Several species are significant ornamental pests, including the azalea lace bug (S. pyrioides) and andromeda lace bug (S. takeyai), which cause characteristic stippling damage on host foliage. The genus has a broad distribution across Asia, Europe, North America, and other regions, with some species introduced outside their native ranges.
Stephanitis pyrioides
Azalea Lace Bug
Stephanitis pyrioides, the azalea lace bug, is an invasive pest native to the East Palaearctic that has spread globally. It is a specialist feeder on Rhododendron species, particularly azaleas, causing characteristic white stippling damage to leaves through mesophyll feeding. The species undergoes multiple generations annually in temperate regions and has become a significant pest of ornamental horticulture.
Stephanitis takeyai
Andromeda lace bug
Stephanitis takeyai, the andromeda lace bug, is a small sap-feeding insect native to Japan that has become an invasive pest of ornamental Ericaceae in North America and Europe. It is closely associated with Pieris japonica (Japanese andromeda), its preferred host, but has been documented on multiple genera within Ericaceae including Rhododendron, Vaccinium, and Kalmia. The species exhibits facultative seasonal host alternation in parts of its native range, moving from evergreen Pieris japonica in winter to deciduous Lyonia elliptica in summer when the latter is available.
Stictocephala
buffalo treehoppers
Stictocephala is a genus of treehoppers in the family Membracidae, characterized by a prominent pronotum that extends over the body. The genus contains approximately 18 described species, most distributed in North America. Several species, notably S. bisonia, have become invasive pests in Europe and Asia, with documented spread to Russia, China, and India. These invasions have occurred primarily within the last 20-30 years, facilitated by climate change and global trade.
Supella longipalpa
brown-banded cockroach, brownbanded cockroach, TV roach
Supella longipalpa, commonly known as the brown-banded cockroach, is a small synanthropic pest of presumed African origin that has become established in human-built structures worldwide. It is notable for pronounced sexual dimorphism: males are slender with long, functional wings and are capable of flight, while females are broader with short, non-functional wings. The species completes its entire life cycle indoors and shows distinct behavioral preferences for warmer, drier locations compared to other domestic cockroaches, often inhabiting furniture, appliances, and upper wall areas.
Symmetrischema tangolias
South American potato tuber moth, Andean potato tuber moth, tomato stemborer
Symmetrischema tangolias is a gelechiid moth native to the Andean region of South America that has become a globally significant agricultural pest. The species infests solanaceous crops, particularly potatoes and tomatoes, with larvae burrowing into stems, leaves, petioles, and tubers. It has established invasive populations in North America, Australia, New Zealand, Indonesia, and Chile. The species is adapted to cooler temperatures than the related potato tuber moth Phthorimaea operculella, with optimal development occurring between 14–17°C.
Synthesiomyia
Synthesiomyia is a small genus of muscid flies in the family Muscidae. The genus contains at least one well-documented species, Synthesiomyia nudiseta, which has gained forensic importance as a carrion-associated fly in tropical, subtropical, and recently colonized Palearctic regions. Species in this genus exhibit facultative predatory behavior and are used in postmortem interval estimation.
Tachystola hemisema
Tachystola hemisema is a small moth in the family Oecophoridae. Originally described from Australia in 1885, it has established invasive populations in New Zealand and the United States. The species is believed to have been transported internationally with Australian plant material.
Talitroides alluaudi
Alluaudi's landhopper
A terrestrial amphipod (landhopper) native to the Atlantic forests of southeastern Brazil, now distributed worldwide through synanthropic human-mediated dispersal. Found in leaf litter of tropical and subtropical forests, urban parks, greenhouses, and silviculture areas. Females dominate populations with a strongly female-biased sex ratio observed in field samples. Exhibits highly stereotyped grooming behavior for hygiene maintenance.
Tarophagus colocasiae
Taro Planthopper
Tarophagus colocasiae is a sap-feeding planthopper in the family Delphacidae, commonly known as the taro planthopper. It is strongly associated with its primary host plant, taro (Colocasia esculenta), and is native to Southeast Asia, Indonesia, and Pacific islands. The species was first detected in the continental United States in Florida in 2015, representing a recent introduction to North America. Its potential economic impact in new regions remains under evaluation.
Tasgius ater
Large rove beetle
Tasgius ater is a large rove beetle in the family Staphylinidae, native to Europe and now introduced to North America, Australia, and New Zealand. It is among the larger species in this diverse beetle family and exhibits typical rove beetle morphology with shortened elytra exposing most of the abdomen. The species has expanded its range significantly in North America since first detected in the 1930s.
Tempyra biguttula
Large-spotted Seed Bug
Tempyra biguttula is a minute dirt-colored seed bug in the family Rhyparochromidae. Native to North America, Mexico, and the Caribbean, it has established populations across Oceania including Hawaii and the Galapagos Islands. The species has recently expanded into the Mediterranean region, with confirmed records in Spain, Portugal, France, and Croatia. It is attracted to light and has been documented exhibiting teratological antennae abnormalities.
Tenodera sinensis sinensis
Chinese praying mantis, Chinese mantis
Tenodera sinensis sinensis, the Chinese praying mantis, is a large non-native mantis in North America, first discovered in 1897 near Philadelphia, likely arriving as a stowaway in nursery stock from Asia. It has become one of the most well-known exotic mantids in the United States, recognized for its substantial size and effective predation on pest insects including the brown marmorated stink bug and spotted lanternfly. The species exhibits flexible hunting strategies that shift between active pursuit and ambush predation depending on satiety level. Adults typically appear in September, with females depositing brown, styrofoam-like egg cases (oothecae) on upright vegetation that overwinter and hatch in spring.
Thereuonema
Thereuonema is a genus of scutigeromorph centipedes in the family Scutigeridae. The genus contains at least one well-documented species, Thereuonema tuberculata, which is native to Asia and has been introduced to Europe and North America. Members of this genus are associated with human-modified environments and have established populations outside their native range.
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.
Trichocorixa
water boatmen
Trichocorixa is a genus of water boatmen in the family Corixidae comprising approximately 14 described species. Members of this genus are notable for their exceptional tolerance of saline and hypersaline habitats, ranging from brackish coastal marshes to salt ponds with salinities exceeding 150‰. Several species have become invasive outside their native ranges, with documented ecological impacts through predation on brine shrimp and other zooplankton. The genus exhibits complex life history adaptations including staggered egg hatching, salinity-dependent embryonic development, and overwintering strategies that vary among species and populations.
Trypodendron domesticum
European hardwood ambrosia beetle
Trypodendron domesticum is a European ambrosia beetle in the family Curculionidae. It is a wood-boring pest of hardwoods that has been introduced to North America. The species is morphologically similar to the closely related T. lineatum, requiring molecular methods for reliable identification. It is one of four Trypodendron species documented in Europe.
Tychius meliloti
Sweet Clover Weevil
Tychius meliloti is a small weevil in the tribe Tychiini, native to Europe and introduced to North America. In Canada, it has been recorded from scattered localities in Saskatchewan, Manitoba, Ontario, and Quebec. The species is associated with sweet clover (Melilotus spp.) as host plants. It represents one of four European Tychius species established in North America.
Ulomoides
Chinese beetle, Chinese weevil, peanut beetle, cancer beetle, asthma beetle, gorgojo chino
Ulomoides is a genus of darkling beetles (Tenebrionidae) native to Asia. The most well-known species, Ulomoides dermestoides, has spread globally due to human cultivation for alleged medicinal purposes. Members of this genus are stored product pests that feed on grain and grain products. The beetles produce defensive quinones that have cytotoxic properties.
Uroleucon sonchi
Sow-thistle Aphid, Large Sow-thistle Aphid, Brown Lettuce Aphid
Uroleucon sonchi is a large aphid species in the family Aphididae, commonly known as the sow-thistle aphid or brown lettuce aphid. Native to the Palaearctic region, it has been introduced to multiple continents and is now cosmopolitan in distribution. The species is economically significant as a pest of cultivated lettuce and related crops, while also occurring on wild Asteraceae hosts. It reproduces parthenogenetically during spring and summer, typical of many aphids.
Vasates quadripedes
Maple Bladdergall Mite, maple bladder-gall mite
Vasates quadripedes is an eriophyid mite known for inducing distinctive bladder-like galls on maple leaves. The species is native to North America and has been introduced to parts of Europe, including Britain where it was first recorded in 2002. It is associated primarily with silver maple, red maple, and sugar maple. The galls it produces are a reliable indicator of its presence and are more readily observed than the microscopic mites themselves.
Vatiga
cassava lace bugs
Vatiga is a genus of lace bugs (family Tingidae) containing approximately 11 described species. The genus is native to the Neotropical region and has become economically significant as an invasive pest in cassava-growing regions worldwide. Species in this genus are highly host-specific, feeding exclusively on cassava (Manihot esculenta). The most extensively studied species are Vatiga illudens and Vatiga manihotae, which have been introduced to Indonesia and Africa, posing threats to food security in these regions.
Vespinae
Hornets and Yellowjackets
Vespinae is a subfamily of eusocial wasps within Vespidae, encompassing the largest and most familiar social wasps. The subfamily includes true hornets (genus Vespa), yellowjackets (genera Dolichovespula and Vespula), and the poorly known nocturnal genus Provespa from Southeast Asia. These wasps construct paper nests from chewed wood fibers and exhibit complex colonial organization with queen-worker caste differentiation. Several species have become invasive beyond their native ranges, posing significant threats to apiculture and native ecosystems.
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.
Xyleborus affinis
sugarcane shot-hole borer
Xyleborus affinis is a highly widespread ambrosia beetle native to the American tropics, now found in tropical and subtropical regions worldwide. It cultivates symbiotic fungi in galleries bored into decaying wood, feeding exclusively on these fungal gardens. The species exhibits facultative eusociality with delayed dispersal of adult offspring, who assist with nest maintenance and brood care. Females are the dispersing sex and are strongly attracted to ethanol and specific host plant volatiles. Despite frequent association with declining trees, it primarily colonizes wood already in early decay rather than causing primary mortality.
Xystrologa grenadella
Xystrologa grenadella is a small moth in the family Tineidae. It has been documented as an invasive pest in greenhouse environments in southern Florida, USA and Germany. The species is native to the West Indies, with type locality in Grenada.
Zapatella
Zapatella is a genus of gall wasps in the family Cynipidae. The genus includes at least one well-documented species, Z. davisae, which has become a significant pest of black oak (Quercus velutina) in the northeastern United States. Gall wasps in this genus induce gall formation on oak hosts. The genus was described in 2012 by Pujade-Villar & Melika.
Zapatella davisae
black oak gall wasp
Zapatella davisae is a cynipid gall wasp (Hymenoptera: Cynipidae) described in 2016 that has become a significant pest of black oak (Quercus velutina) in the northeastern United States. Larvae develop under bark in late summer, with adults emerging in early spring. The species has undergone notable population outbreaks on Long Island, NY (first documented 1990), Cape Cod and Martha's Vineyard, MA (2008), and more recently in coastal Rhode Island and Nantucket, MA. High parasitism rates by Sycophila species can lead to rapid population collapse, as observed on Long Island in 2016.
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.