Cellar Spiders - School IPM - USU Extension

    Cellar Spiders

    Pholcus sp.

    Cellar spider eyes

    Cellar spider eyes (Joseph Berger, Bugwood.org)

    Spider with Eggs

    Adult cellar spider with eggs (Olei, Wikimedia Commons)

    Cellar Spider

    Adult cellar spider (Joseph Berger, Bugwood.org)

    Identification

    • long delicate legs with small, elongate or globular body
    • pale tan or yellow with a gray mark in the center of the carapace

    Nesting Habits

    • common in basements, crawlspaces and behind HVAC units, furniture, pianos and other seldom-moved objects, but can occur outdoors, too
    • make irregular cobwebs near windows, over pipes, or all over the ceiling and walls, especially in corners
    • female spider carries eggs in her fangs

    Diet

    • insects and other arachnids

    Significance

    • webs build up over time and collect dirt/dust making areas where they are located unsightly
    • not known to be a health hazard
    • beneficial

    IPM Recommendations

    • Minimize nesting habitat around property (e.g., plants).
    • Seal exterior cracks and crevices to reduce daytime hiding places.
    • Regularly vacuum individuals and webs inside and outside of buildings.
    • Reduce clutter in favored areas.
    • Install tight-fitting door sweeps at the base of all exterior doors.
    • Install tight-fitting screens in windows.
    • Keep windows closed.
    • Reduce other insects that serve as food.
    • Change exterior lighting to sodium vapor bulbs.

    Additional Resources:

    IPM for Spiders: Integrated Pest Management in Sensitive Environments (University of Nebraska-Lincoln Extension)