Nocturnal-predator
Guides
Anuroctonus pococki bajae
Californian swollen stinger scorpion
Anuroctonus pococki bajae is a subspecies of scorpion in the family Chactidae, endemic to Baja California. It is distinguished by a pronounced swollen bulb on the telson (stinger segment), a trait referenced in its common name. The species exhibits defensive, aggressive behavior when provoked and is nocturnal. Under ultraviolet light, it fluoresces bright blue-green like other scorpions.
Cymindis laticollis
A ground beetle species in the subfamily Harpalinae, described by Thomas Say in 1830. Records indicate presence in Canada and the United States. As a member of genus Cymindis, it likely shares the nocturnal predatory habits characteristic of this genus, though specific behavioral observations for this species remain limited.
Cymindis yaqui
Cymindis yaqui is a ground beetle species in the family Carabidae, subfamily Harpalinae, and tribe Lebiini. The species was described from specimens collected in the southwestern United States and adjacent Mexico. It belongs to a genus of small to medium-sized carabid beetles that are generally associated with arid and semi-arid environments. Like other Cymindis species, it is likely nocturnal and predatory, though specific biological details remain poorly documented in the scientific literature.
Diguetia signata
desertshrub spider
Diguetia signata is a species of desertshrub spider in the family Diguetidae, first described by Gertsch in 1958. It inhabits arid regions of the southwestern United States and Mexico, where it constructs distinctive horizontal sheet webs with central tubular retreats. The species belongs to a primitive spider lineage characterized by simple genital structures.
Eremobates bixleri
windscorpion, sun spider, camel spider
Eremobates bixleri is a species of solifuge (windscorpion) in the family Eremobatidae, described by Muma and Brookhart in 1988. Like other solifugids, it is a nocturnal arachnid with large, powerful chelicerae used to capture and kill prey. The species is found in North America, particularly in arid and semi-arid regions. Solifugids are frequently encountered in desert environments and are often mistaken for scorpions or spiders due to their appearance, though they represent a distinct evolutionary lineage.
Eremobates icenogelei
camel spider, sun spider, wind scorpion, solifuge
Eremobates icenogelei is a species of solifuge (camel spider) in the family Eremobatidae. Solifugids are arachnids distinct from spiders and scorpions, characterized by their large, powerful chelicerae and rapid running ability. This species, like other members of its genus, inhabits arid and semi-arid regions of western North America. They are nocturnal predators that actively hunt small arthropods using their formidable jaws rather than venom. Despite their fearsome appearance, they pose no venomous threat to humans, though they can deliver a painful bite if handled carelessly.
Eremobates kiseri
windscorpion, sun spider, camel spider
Eremobates kiseri is a species of solifuge (sun spider or windscorpion) in the family Eremobatidae, described by Muma & Brookhart in 1988. Solifugids are arachnids distinct from spiders and scorpions, characterized by their large, powerful chelicerae (jaws) and rapid movement. Like other members of the genus Eremobates, this species is native to arid and semi-arid regions of North America. The species name honors an individual, following the pattern of many Eremobates species named after collectors or researchers.
Geolycosa hubbelli
Geolycosa hubbelli is a species of burrowing wolf spider in the family Lycosidae. It is found in the United States and belongs to a genus characterized by deep, silk-lined burrows. Members of this genus are typically associated with sandy or loose soil habitats where they construct vertical burrows with debris-reinforced turrets.
Harpalus cohni
Harpalus cohni is a species of ground beetle in the subfamily Harpalalinae, described by George E. Ball in 1972. It belongs to the large genus Harpalus, one of the most diverse genera within the Carabidae family. The species is known from the United States, with distribution records indicating presence in North America. Like other members of Harpalus, it is likely a nocturnal or crepuscular predator, though specific ecological details remain poorly documented due to limited study.
Harpalus katiae
Harpalus katiae is a species of ground beetle in the subfamily Harpalinae, described by F. Battoni in 1985. It belongs to the large genus Harpalus, which contains numerous ground beetle species distributed across multiple continents. As with most members of this genus, it is likely a nocturnal predator inhabiting open, dry habitats, though specific details about its biology remain poorly documented.
Labidura riparia
shore earwig, tawny earwig, striped earwig, riparian earwig
Labidura riparia is a cosmopolitan earwig species found primarily in tropical to subtropical regions. It exhibits complex subsocial behavior with maternal care of eggs and young. The species is a generalist predator valued for biological pest control, with documented predation on Lepidoptera larvae, insect eggs, and crop pests including the Asian corn borer and Mediterranean fruit fly pupae. Males possess two functional penises but show a 90% preference for the right penis during copulation, a behavioral asymmetry unique among earwigs.
Laemostenus complanatus
Cosmopolitan Ground Beetle
Laemostenus complanatus is a ground beetle in the family Carabidae, native to Europe. It has been introduced to the Azores, where it is now established on multiple islands. The species is sometimes called the Cosmopolitan Ground Beetle, reflecting its spread beyond its native range. It belongs to a genus of predominantly nocturnal predatory beetles.
Mastophora cornigera
Southern Bolas Spider
Mastophora cornigera is a bolas spider in the orb-weaver family Araneidae. Adult females are specialized predators that capture male noctuid moths using a single sticky silk droplet suspended from a dragline, rather than constructing a traditional orb web. The species is the only member of its genus found in California. Males and juvenile females lack this hunting adaptation and instead capture prey directly with their legs.
Mastophora stowei
Bolas spider
Mastophora stowei is a species of bolas spider in the orb-weaver family Araneidae, described by Herbert W. Levi in 2003. Like other members of the genus Mastophora, this species has abandoned the construction of traditional orb webs in favor of a specialized hunting technique using a single sticky silk globule suspended on a dragline. The species occurs in the United States and is one of approximately 15 Mastophora species found in North America.
Mastophora yeargani
Yeargan's Bolas Spider
Mastophora yeargani is a bolas spider in the orb-weaver family Araneidae, found in the United States. Adult females are specialized predators that capture prey using a single sticky droplet of silk suspended from a dragline, rather than building an orb web. Males and juvenile females lack this hunting strategy and instead capture prey directly with their legs. The species was described by Levi in 2003 and is one of approximately 15 Mastophora species known from the United States.
Nebria brevicollis
European Gazelle Beetle, Short-collared Gazelle Beetle
Nebria brevicollis is a ground beetle native to Europe and the Near East that has been introduced to western North America. It is a nocturnal, opportunistic predator with a flexible life history involving photoperiod-controlled reproductive diapause. The species exhibits remarkable habitat breadth, from sea level to alpine zones, and shows phenotypic plasticity in flight muscle development based on larval nutrition. Its rapid expansion in the Pacific Northwest has raised questions about potential ecological impacts on native carabid communities.
Phrynus
whip spiders, tailless whip scorpions
Phrynus is a genus of whip spiders (order Amblypygi) comprising approximately 40 described species, primarily distributed in tropical and subtropical regions of the New World. The genus is characterized by dorsoventrally flattened bodies, extraordinarily elongated antenniform front legs used for sensory detection, and raptorial pedipalps for prey capture. Most species inhabit forested environments where they shelter in crevices, under rocks, or in tree holes during daylight hours and emerge nocturnally to hunt. Several species exhibit notable behavioral complexity including territoriality, cannibalism, maternal care of offspring, and sophisticated navigational abilities using multisensory cues.
Phrynus operculatus
tailless whipscorpion
A medium-sized tailless whipscorpion (18–22 mm total length) found across much of Mexico. Distinguished by chestnut coloration with reddish tones on the carapace and pedipalps, four anterior spines on the pedipalp trochanter, and specific female gonopod morphology. The species shows considerable morphological variation across its range, suggesting it may represent a species complex.
Platynus daviesi
Platynus daviesi is a ground beetle species in the family Carabidae. It belongs to the genus Platynus, a group of nocturnal, predatory beetles. The species is known from North America. Information on its biology and ecology remains limited.
Platynus mannerheimii
Platynus mannerheimii is a ground beetle species in the family Carabidae, distributed across boreal and arctic regions of the Northern Hemisphere. It belongs to a large genus of predominantly forest-dwelling carabids characterized by elongated bodies and long legs adapted for running. The species was described by Dejean in 1828 and is named after the Finnish entomologist Carl Gustaf Mannerheim.
Platynus parmarginatus
Platynus parmarginatus is a species of ground beetle in the family Carabidae, first described by Hamilton in 1893. It belongs to the subfamily Platyninae, a group of predominantly nocturnal predatory beetles. The species is documented from the United States within North America. Like other Platynus species, it is likely a generalist predator inhabiting forest floor environments.
Scytodes thoracica
Common Spitting Spider, Spitting Spider
Scytodes thoracica is a small spitting spider renowned for its unique hunting method: projecting venomous, sticky silk threads to immobilize prey. The species possesses six eyes arranged in three pairs and distinctive silk glands in the cephalothorax connected to venom glands, enabling production of venomous silk. Native to the Mediterranean region, it has achieved cosmopolitan distribution through human-mediated dispersal and is frequently encountered in synanthropic habitats.
Theraphosidae
tarantulas, bird spiders, birdeaters
Theraphosidae is a family of large, often hairy spiders commonly known as tarantulas. The family comprises approximately 900 described species distributed across tropical, subtropical, and arid regions worldwide. Tarantulas are characterized by their substantial size, with some species reaching leg spans up to 30 cm, and their longevity—females of certain species can live 20 to 30 years. They are primarily nocturnal predators that employ diverse hunting strategies including ambush from burrows, active pursuit, and arboreal hunting. The family exhibits considerable ecological diversity, with species occupying terrestrial burrowing, arboreal, and even cave-dwelling niches.
Tliltocatl vagans
Mexican red-rump tarantula, Mexican red rump
Tliltocatl vagans is a large terrestrial tarantula native to Mexico and Central America, distinguished by the distinctive red hairs covering its abdomen. Formerly placed in the genus Brachypelma, this species was reclassified to Tliltocatl following taxonomic revision accepted by the World Spider Catalog. It is a burrowing, nocturnal predator that constructs underground galleries. The species has established a non-native population in Florida since 1996, introduced through the pet trade. Females are notably long-lived, potentially reaching 25–40 years in captivity. Due to habitat destruction, collection pressure, and high juvenile mortality, T. vagans is considered vulnerable to extinction and is protected under CITES Appendix II.
Zelotes pseustes
Zelotes pseustes is a species of ground spider in the family Gnaphosidae, first described by Chamberlin in 1922. It belongs to a large genus of active hunters that do not build webs to capture prey. The species is distributed across the United States and Mexico. Like other Zelotes species, it is a nocturnal predator that pursues prey on the ground or on low vegetation.
Zelotes subterraneus
Ground spider
Zelotes subterraneus is a ground spider in the family Gnaphosidae and the type species of the genus Zelotes. It has a Palearctic distribution across Europe, Asia, and North Africa. The species is notoriously difficult to identify, particularly females, due to striking similarity with congeners Zelotes apricorum and Zelotes latreillei. Males can be distinguished by examination of embolus structure on the pedipalps. Body length ranges from 3.8-7.8 mm in males and 5.8-9.2 mm in females. It is an active nocturnal hunter that does not build webs for prey capture.