Conservation-concern
Guides
Sepedomerus macropus
Liverfluke Snail Predator Fly
A marsh fly in the family Sciomyzidae, native to the American tropics and subtropics. The larvae are specialized predators of lymnaeid pond snails, which serve as intermediate hosts for the liver fluke Fasciola gigantica. The species has been intentionally introduced to Hawaii, Guam, and Thailand as a biological control agent for snail vectors of fascioliasis. In Hawaii, introduced populations have become invasive, threatening native lymnaeid snail species including the endangered Newcomb's snail.
Shotwellia
Shotwellia is a monotypic genus of band-winged grasshoppers in the family Acrididae. The sole described species, Shotwellia isleta, is a rare North American grasshopper known from limited locations in the Chihuahuan Desert. It has historically been difficult to classify phylogenetically due to its unique morphological characteristics. The genus is currently placed within the Chortophaga genus group based on molecular and morphological evidence.
Shotwellia isleta
Shotwellia isleta is a rare, monotypic band-winged grasshopper described by Gurney in 1940. Molecular phylogenetic analysis places it as sister to other genera within the Chortophaga genus group of Oedipodinae. The species is a habitat specialist restricted to isolated locations in the Chihuahuan Desert.
Sideridis maryx
Maroonwing Moth
Sideridis maryx, the maroonwing moth, is a North American noctuid moth first described by Achille Guenée in 1852. It is of conservation concern in parts of its range, having been declared extirpated in Connecticut where it holds special concern status. The species' biology remains poorly documented, with its larval host plant unconfirmed.
Somatochlora brevicincta
Quebec Emerald, Robert's Emerald
Somatochlora brevicincta is a rare dragonfly in the family Corduliidae, first described by Canadian entomologist Adrien Robert in 1954. It belongs to the 'ringed' group of emeralds, distinguished by faint whitish rings on the abdomen. The species is among the rarest Odonata in Canada, with a transcontinental distribution across boreal and subarctic regions. It is classified as vulnerable to critically imperiled across most of its range.
Somatochlora calverti
Calvert's Emerald, Andre Flies
Somatochlora calverti is a rare, range-restricted dragonfly in the family Corduliidae. It is endemic to the southeastern United States, primarily known from the Florida panhandle with scattered records in Alabama, Georgia, and South Carolina. The species is a habitat specialist associated with shallow seepage streams and steephead ravines. Its nymph has never been collected in the field, and its reproductive microhabitat remains speculative based on analogy to sympatric congeners.
Somatochlora margarita
Texas emerald
Somatochlora margarita, the Texas emerald, is a dragonfly endemic to the United States with a highly restricted range in eastern Texas and western Louisiana. It inhabits river systems and is rarely observed due to its habit of perching in forest canopies. The species was described by Donnelly in 1962 and is considered one of the more poorly known North American emeralds.
Speyeria adiaste
unsilvered fritillary, adiaste fritillary
Speyeria adiaste is a California-endemic fritillary butterfly in the family Nymphalidae, distinguished from congeners by the unsilvered hindwing spots that give it its common name. The species occurs in two disjunct populations in coastal California mountains. Adults feed on flower nectar and larvae feed on Viola species. Mark-recapture studies of the subspecies S. a. clemencei have revealed extremely limited adult dispersal and declining population trends, highlighting conservation concerns for this isolated endemic.
Speyeria nokomis
Nokomis fritillary
Speyeria nokomis, the Nokomis fritillary, is a North American butterfly in the family Nymphalidae. The species has a highly specialized relationship with its host plant, with larvae feeding exclusively on northern bog violet (Viola nephrophylla). It is currently recognized with nine subspecies, including the imperiled Carson Valley silverpot butterfly (S. n. carsonensis), which has experienced significant population declines. Conservation efforts focus on habitat restoration through propagation of its obligate host plant.
Sphinx
sphinx moth, hawk moth, hummingbird moth
Sphinx is a genus of moths in the family Sphingidae, first described by Linnaeus in 1758. These moths are commonly known as sphinx moths, hawk moths, or hummingbird moths due to their rapid, hovering flight and large size. The genus includes several ash-specialist species that have become conservation concerns due to decline of their host trees from emerald ash borer infestation. The name derives from the caterpillar's defensive posture when disturbed—rearing up with head retracted, resembling the Egyptian sphinx.
Sphinx chersis
Great Ash Sphinx, Northern Ash Sphinx
Sphinx chersis is a large sphinx moth commonly known as the great ash sphinx or northern ash sphinx. Adults are active from May to August in southern regions and June to July in northern areas. The species is an ash specialist whose larvae feed on plants in the olive family (Oleaceae), particularly ash (Fraxinus), lilac (Syringa), and privet (Ligustrum). Research indicates that while larvae can develop on some non-native host plants, survival and development rates vary significantly compared to native ash.
Sphodros
purseweb spiders
Sphodros is a genus of mygalomorph spiders in the family Atypidae, native to North America. The genus was reinstated in 1980 after being treated as a synonym of Atypus for over a century. Seven species are recognized, distributed across the United States, Canada, and Mexico. These spiders are known for constructing distinctive purse-shaped webs attached to tree trunks and root systems.
Sphodros niger
Black purse-web spider, Black Purseweb Spider
Sphodros niger is a mygalomorph spider native to northeastern North America. Males reach approximately 11 mm in body length (29 mm with legs extended) and possess distinctive chocolate-brown legs contrasting with an otherwise black body. Females were not described until 1980, 138 years after the species was first named, due to their sedentary tube-dwelling behavior. The species is listed as a special concern species in Connecticut and ranked as vulnerable in Virginia.
Sympistis perscripta
Scribbled Sallow, scribbled sallow moth
Sympistis perscripta, commonly known as the scribbled sallow moth, is a noctuid moth native to North America. It was first described by Achille Guenée in 1852. The species is listed as a species of special concern in Connecticut and Massachusetts, indicating conservation interest in portions of its range.
Sympistis riparia
dune sympistis, dune oncocnemis
Sympistis riparia is a noctuid moth native to North America, first described by Herbert Knowles Morrison in 1875. The species is known by two common names: dune sympistis and dune oncocnemis. It holds conservation significance, having been designated as a species of special concern in both Massachusetts and Connecticut. The specific epithet 'riparia' suggests an association with riverbank or shoreline habitats, though this ecological connection has not been explicitly documented in available sources.
Thaumatopsis edonis
Grassland Thaumatopsis
Thaumatopsis edonis is a crambid moth described by Augustus Radcliffe Grote in 1880. It is listed as threatened in Connecticut and has been recorded across ten US states from Florida to Nebraska. Adults are active in late summer and autumn.
Thesium
Rootthugs
Thesium is a genus of hemiparasitic flowering plants in the family Santalaceae, with approximately 325 species distributed primarily across Africa, Europe, and Asia. The genus is particularly diverse in South Africa, where roughly half of all species occur. Species in this genus are root hemiparasites that form haustorial connections to host plant roots. The genus has undergone taxonomic revision, with several segregate genera (Austroamericium, Chrysothesium, Kunkeliella, Thesidium) now subsumed within Thesium.
Toxomerus
Calligrapher Flies
Toxomerus is a large genus of hoverflies (family Syrphidae) distributed across the Americas, with over 130 described Neotropical species and additional Nearctic endemics. Species are small (typically 6–9 mm), characterized by large eyes with posterior indentation and diagnostic abdominal patterns. Most larvae are predatory on soft-bodied insects, particularly aphids, though at least three species are known pollen-feeders. Adults are pollinivorous, feeding on nectar and pollen from diverse flowering plants. The genus includes notable ecological specialists such as Toxomerus basalis, a kleptoparasite of sundews (Drosera), and several species introduced to the Afrotropics.
hoverflyflower-flyaphid-predatorpollinatorbiological-controlHymenoptera-mimickleptoparasiteintroduced-speciesNeotropicalNearcticAfrotropical-introductionpolyvoltineSyrphiniSyrphinaeDipteraSyrphidaeToxomerus-marginatusToxomerus-disparToxomerus-pulchellusToxomerus-basalisToxomerus-floralisToxomerus-politusToxomerus-apegiensisDroserasundewpollenivorypredatory-larvaeurban-adapteragricultural-beneficialcryptic-larvaeeye-dimorphismterritorial-behaviorDNA-barcodingcitizen-sciencemuseum-collectionsrange-expansionconservation-concernTrechus obtusus
Trechus obtusus is a ground beetle species in the family Carabidae, originally described from Europe and now established as an invasive species in Hawaii. It has been documented in large numbers in pitfall traps at Pu'u Maka'ala Natural Area Reserve on the island of Hawaii, where it may compete with or displace native carabid species. The species has a broad native distribution spanning North America, Europe, and Africa, with six recognized subspecies showing regional variation.
Trichiotinus rufobrunneus
Florida flower scarab
Trichiotinus rufobrunneus is a species of flower scarab beetle endemic to Florida, commonly known as the Florida flower scarab. It belongs to the genus Trichiotinus, a North American endemic group of trichiine scarabs. The species is associated with the flowers of Opuntia australis (Florida pricklypear cactus), an endemic plant, and has been observed mating within these flowers. Its distribution is limited to Florida, making it a species of conservation concern due to habitat loss from urban development and agriculture.
Trichodesma
Barbbells
Trichodesma is a genus of flowering plants in the borage family (Boraginaceae), comprising approximately 38 accepted species. The genus is distributed across tropical and subtropical regions of Africa, Asia, and Australia. Members are herbaceous plants with medicinal properties, particularly T. indicum, which is utilized in traditional medicine and has been subject to conservation concerns due to overexploitation.
Trogloraptor
Cave robber
Trogloraptor is a genus of large cave-dwelling spiders endemic to southwestern Oregon, representing the sole genus in the family Trogloraptoridae. The genus contains one described species, Trogloraptor marchingtoni, distinguished by unique hook-like claws on the tarsi of its legs. Discovered in 2010 and described in 2012, this represents one of only three new spider families described since 1990. The genus name combines Greek and Latin roots meaning "cave robber," referencing both its habitat and predatory appendages.
Typhlonesticus silvestrii
Silvestri's Cave Spider
Typhlonesticus silvestrii is a troglobitic spider in the family Nesticidae, first described by Fage in 1929. The species is endemic to cave systems and exhibits adaptations typical of obligate cave-dwellers, including reduced pigmentation and elongated appendages. It represents one of the specialized members of the genus Typhlonesticus, which comprises European cave spiders with restricted distributions. The species was originally described under the genus Nesticus before being transferred to Typhlonesticus.
Ucides cordatus
swamp ghost crab, caranguejo-uçá, Atlantic mangrove ghost crab
Ucides cordatus is a large mangrove crab endemic to the Atlantic coast of the Americas, ranging from Florida to Uruguay. It is one of two species in the genus Ucides and holds substantial economic and ecological importance, particularly in Brazil where it supports artisanal fisheries. The species exhibits pronounced sexual dimorphism, with females typically larger than males and differing in carapace coloration. Population declines have been documented since 1988 due to overharvesting, habitat loss, and disease.
Venezillo microphthalmus
Small-eyed Venezillo Pill Woodlouse
Venezillo microphthalmus is a small terrestrial isopod in the family Armadillidae, endemic to California. The species exhibits the characteristic conglobation (pill-forming) behavior typical of its family, rolling into a defensive ball when disturbed. It is considered rare on the mainland and has documented populations on the Channel Islands. The species is believed to be declining in the San Francisco Bay Area due to competition from introduced woodlouse species.
Xiphosura
horseshoe crabs
Xiphosura is an order of marine chelicerate arthropods commonly known as horseshoe crabs. The group contains only four extant species, all within the family Limulidae. Xiphosurans first appeared in the fossil record approximately 480 million years ago and have retained a remarkably conserved body plan, earning them designation as living fossils. Recent phylogenomic studies have placed Xiphosura within Arachnida, often as the sister group to Ricinulei, though this classification remains under active revision. The order contains one extant suborder (Xiphosurida) and numerous extinct stem-genera.