Plectreurys tristis
Simon, 1893
primitive hunting spider
Plectreurys tristis is a large venomous spider in the Plectreuridae, found in arid and semi-arid regions of western North America, Central America, and Mexico. males reach approximately 12 mm in body length (25 mm with legs extended), with females larger in all proportions. The produces a venom containing plectoxins, insecticidal that specifically target N-type calcium channels. It constructs webs under rocks and debris, with females and immatures remaining in webs while adult males wander nocturnally.
Pronunciation
How to pronounce Plectreurys tristis: /plɛkˈtrʊərɪs ˈtrɪstɪs/
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Identification
Distinguished from related by stout, densely hairy legs lacking long spines. The granulated, setae-free and yellowish-grey rounded with matching setae coloration are diagnostic. The combination of large size, dark brown unmarked and legs, and absence of leg spines separates it from other plectreurids.
Appearance
Large, robust spider with dark brown, unmarked and legs. Legs stout and densely hairy but lacking long spines. rough (granulated) and without setae. nearly rounded, yellowish-grey with similarly colored setae. Eight arranged in two rows. male body length approximately 12 mm, about 25 mm with legs stretched; females larger in all proportions.
Habitat
Arid and semi-arid regions including deserts, dry woodlands, and coniferous forests up to 2,000 m elevation. Constructs webs under rocks, wood, and other debris in dry terrestrial . Has been observed in urban areas where suitable web-building substrates exist.
Distribution
Southwestern North America (California, Nevada, Idaho, Arizona, Utah), Central America, and Mexico.
Behavior
Females and individuals remain in webs; males wander nocturnally. Visually weak even during hunting; relies on venom to kill or paralyze prey including other arachnids. Constructs webs under available cover in dry .
Human Relevance
Venom contains plectoxins with high insecticidal activity against lepidopteran insects, of potential interest for pest control research. Bites to humans are rare; one documented case (1991, Kern County, California) involved severe initial pain, edema, pallor, and transient numbness resolving within two hours without medical intervention.
Similar Taxa
- Other Plectreurys speciesDifferentiated by leg spine presence, texture, and setae patterns
- Other plectreurid spidersP. tristis lacks the long leg spines characteristic of related