Western Black Widow
Latrodectus hesperus
The Western Black Widow is the predominant black widow species across the western United States. Like the Southern species, the female is glossy black with a red hourglass. It is commonly found in outdoor structures, garages, and rock walls in arid and semi-arid environments.
Identification
Size
8-13 mm (female body)
Color
Glossy black with a complete red hourglass on the ventral abdomen
Key Trait
The primary black widow species in western North America; red hourglass is typically complete and well-defined.
Behavior & Habitat
Females construct irregular webs in sheltered, low locations. Active primarily at night. Males are much smaller and wandering males are sometimes found indoors during mating season.
Habitat: Rock walls, wood and brush piles, garages, sheds, outdoor furniture, irrigation boxes, and crawl spaces. Common in arid western landscapes.
Diet: Insects and small arthropods captured in webs.
Signs of Infestation
- Irregular webs in garage corners, under eaves, and around outdoor equipment
- Glossy black spider with red hourglass in sheltered outdoor spots
- Wandering male spiders found indoors during summer
Risks & Damage
Neurotoxic venom causes latrodectism; medical attention is recommended for all bites.
Prevention Tips
- 1.Wear gloves when working around rock walls, woodpiles, and outdoor storage
- 2.Install yellow lighting near doors to reduce prey insect attraction
- 3.Seal gaps around garage doors and utility entries
- 4.Clear debris and clutter from around the home exterior
Why DIY Treatment Often Falls Short
Like other black widows, they inhabit recessed crevices that surface sprays cannot reach. A comprehensive perimeter and harborage treatment plan is needed.
Professional Treatment
Professionals apply targeted residual treatments to exterior harborage areas, perimeter sprays to reduce prey insects, and web removal. Quarterly service maintains long-term control.
Frequently Asked Questions
Is the Western Black Widow dangerous?
Are black widows common in my garage?
How can I avoid being bitten?
Need Help With Western black widow?
If you're seeing signs of western black widow in or around your home, professional treatment is the fastest way to stop the problem. Lotus Pest Control offers free inspections to identify the issue and recommend the right solution.
At a Glance
- Category
- Spiders
- Scientific Name
- Latrodectus hesperus
- Size
- 8-13 mm (female body)
- Color
- Glossy black with a complete red hourglass on the ventral abdomen
- Key Trait
- The primary black widow species in western North America; red hourglass is typically complete and well-defined.
- Regions
- Southwest, Pacific Northwest, South Central
- Threat Level
- High
- Risk Types
- health
- Seasonal Activity
- MarAprMayJunJulAugSepOctNovDecJanFebnonelowmoderatehighpeak