Spiders

categories: Natural Enemies Other Natural Enemies

last review date: 2025-08-23 05:54

Biology

Spiders generally evoke negative emotions in people but you should truly be grateful for their presence in your garden! The pest control service they provide is enormous and greatly under-appreciated. There are more than 800 species of spiders in Washington State, and the average pesticide-free home garden is likely to be home to perhaps 20-25 species.

Spiders occupy a range of habitat niches with correspondingly different behaviors and prey preferences. There are three main groups of spiders: those that spin and sit in webs to catch their prey, those that are very active, foraging for prey, often running it down, and those that sit still, ‘ambushing’ prey when it comes too close.

Garden web builders are perhaps least threatening to people because they are fixed in location and not likely to surprise anybody (except the unfortunate winged insects that get caught in the web). Most often seen in late summer and autumn, orb-weaving or garden spiders spin their prominent and sometimes large webs in bushes and on buildings, fences etc, catching and feeding on any winged insect that gets trapped.

Hunting spiders patrol backyards constantly searching for prey. Some species specialize on ground-living prey, others roam over plants and trees while others prefer to hunt on structures like fences and buildings. Jumping spiders (salticids) are small to medium–sized spiders (1/4 to ½ inch) with good eyesight that jump and pounce on their prey and are commonly seen in Pacific Northwest gardens. All hunting spiders find and devour a great number of insects every day.

Ambush spiders are masters of disguise, quietly waiting for prey to come to them. Crab spiders (1/4 to ½ inch) are ambushers that often wait in blooming flowers for insects seeking nectar or pollen. Some sit on leaves waiting for an insect to land. Invariably, crab spiders are identically colored to their background, and some can even change color according to background.

Spend a little time looking for spiders in your garden and watch what they do. Your negative feelings towards spiders may just become positive!

Prey or Pest Targeted

• Aphids, mites, caterpillars, flies, wasps, beetles, wasps, bees, grasshoppers, leafhoppers, whiteflies, thrips, mealybugs, moths, butterflies

Attracting and Keeping Natural Enemies
and Pollinators in Your Yard and Garden

• Native plants provide essential resources.
• Native flora also provides natural overwintering sites.
• Natural dispersion from nearby habitats ensures visitation.
• Some kinds of beneficial insects predatory mites are commercially available.
• Avoid regular use of synthetic, broad-spectrum pesticides.
• Infrequent use of certain narrow-spectrum pesticides is more compatible with some beneficials.
• Extensive lawns are also not conducive to attracting beneficial insects.

Management Options

See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

• None recommended