Spiders are abundant throughout the Inland Empire, with our region’s diverse habitats supporting numerous species. While most spiders benefit our ecosystem by controlling insect populations, knowing which species warrant caution helps Upland residents coexist safely with these eight-legged neighbors.

Beneficial Spiders Common in Upland Homes

• Cellar Spiders (Daddy Long-legs): These harmless spiders with extremely long, thin legs build messy cobwebs in corners, basements, and garages. They actually prey on other spiders, including more dangerous species, making them beneficial natural pest controllers. Despite urban myths, cellar spiders are not venomous to humans. Their small fangs cannot penetrate human skin effectively.
• Jumping Spiders: Small, fuzzy spiders that hunt actively rather than building webs. Their distinctive jumping behavior and large front eyes make them easily recognizable. Though capable of biting, their venom isn’t medically significant to humans. These intelligent hunters have excellent vision and can jump up to 50 times their body length. Many Inland Empire species display fascinating courtship behaviors with intricate dances and colorful displays.
• Orb Weavers: These impressive web builders create the classic circular webs often seen in gardens and between outdoor structures. Coming in various sizes and colors, they’re harmless to humans despite their sometimes intimidating appearance. Orb weavers typically rebuild their webs daily, consuming the old silk to recycle its proteins. The geometric precision of their webs helps them target specific flying insect prey that plague Inland Empire gardens.
• Wolf Spiders: Fast-moving ground hunters that chase prey rather than building webs. Though large and sometimes alarming when spotted, wolf spiders avoid human contact and their bites rarely cause more than minor pain and irritation. Female wolf spiders carry their egg sacs attached to their spinnerets and later carry their spiderlings on their backs, providing maternal care unusual among arachnids. They’re particularly beneficial for controlling cockroaches and other ground-dwelling pests.

Spiders of Medical Concern

• Black Widows: The most medically significant spider in the Inland Empire, identifiable by their shiny black bodies and distinctive red hourglass marking on the underside of the abdomen. They prefer dark, undisturbed areas like woodpiles, outdoor furniture, and cluttered garages. While their neurotoxic venom can cause serious symptoms, modern medical care means fatalities are extremely rare. Black widows are shy and non-aggressive, biting only when directly threatened or accidentally pressed against the skin.
• Yellow Sac Spiders: Pale yellow to beige spiders that build silk retreats rather than webs. Common in Upland homes, their bites can cause painful wounds that heal slowly but rarely require medical intervention. These nocturnal hunters are often responsible for mysterious overnight bites, as they frequently crawl onto beds while hunting at night. Yellow sac spiders build small silk sacs in corners of ceilings and walls, emerging at night to hunt.
• False Black Widows: Similar in appearance to black widows but lacking the red hourglass marking. Their bites can cause localized pain and swelling but are less severe than true black widow bites. These spiders are becoming increasingly common in Southern California homes and can be confused with juvenile black widows. Their populations have expanded significantly in the Inland Empire over the past decade.

Spider Prevention Strategies

Minimize spider populations in and around your home with these approaches:

• Reduce harborage areas: Eliminate clutter in garages, attics, and storage areas where spiders can hide undisturbed. Store items in sealed plastic containers rather than cardboard boxes, which provide ideal hiding spots.
• Regular cleaning: Vacuuming corners, removing cobwebs, and disturbing potential hiding spots discourages spider settlement. Focus on areas behind furniture, under beds, and in seldom-used areas where spiders prefer to establish themselves.
• Exterior maintenance: Trim vegetation away from your home’s exterior, move woodpiles away from structures, and eliminate outdoor clutter. Spiders often establish themselves outdoors before moving inside, so creating a buffer zone around your foundation helps prevent entry.
• Seal entry points: Close gaps around windows, doors, utility entrances, and foundation cracks to prevent spiders from entering. Even tiny openings can provide access for spiders seeking shelter or prey.
• Address prey sources: Controlling the insects that spiders feed on reduces your home’s attractiveness to hunting spiders. Reducing exterior lighting that attracts flying insects can significantly decrease spider activity around entry points.
• Targeted treatments: Apply residual insecticides to exterior perimeters, focusing on foundation cracks, eaves, and other entry points where spiders typically access homes.

When to Seek Professional Help

Consider professional spider control when:

• You identify black widows or other concerning species around your home
• Spider populations persist despite prevention efforts
• Family members have arachnophobia or spider anxiety
• Spiders consistently reappear in living spaces despite removal efforts
• You’re preparing to sell your home and need to address spider issues
• You live in an area with high spider pressure due to surrounding natural habitats

At Bug Baron, our spider control programs focus on comprehensive interior and exterior treatments that target active spiders while addressing the conditions that attract them. Our technicians are experts at identifying medically important species and implementing targeted control strategies.

Contact Bug Baron today for effective spider management that keeps your Upland home safe and comfortable.