A black widow spider guarding an egg sac, not actual size.
By Stephanie Hughes
OSU Extension Master Gardener Volunteer
The unpopularity of spiders is legendary.
A few — black widow, brown recluse— have such reputations that people dislike and are fearful of all spiders.
Actually, the vast majority of spiders are harmless. The venom of most is not very toxic, usually only a slight swelling, inflammation, or itching, if a person gets bitten at all. Most spider fangs are too small or weak to bite into skin.
Spiders are a benefit as predators, to reduce pest populations such as crickets, flies, mites, etc., around or in the home, yard, garden and other crops.
It is important to be able to identify a spider. They all feed on live prey, using venom to immobilize, and begin digestion. They build webs to ensnare prey, and these can be used to aid in identification. There are cobweb, orb weaver, cellar, and funnel web spiders.
Active hunters (wolf, jumping, nursery and web spiders) use their webs for resting. Passive hunters (crab spider) lie in wait, then jump prey.
There are spider relatives that can infest the home. Pseudoscorpions, mites, ticks, daddy- long-legs (also called harvestmen) are a few in our area, but these are not actually spiders.
Integrated Pest Management (IPM) should be used to control spiders. IPM begins with proper identification. This helps you determine management.
Preventing bites is important. to eliminate places spiders hide:
• Shake out clothing and shoes before dressing
• Inspect bedding and towels before use
• Wear gloves when handling firewood, lumber, rocks
• Remove bedskirts; move bed away from the wall
• Do not store items under beds
• Be careful handling cardboard boxes (under flaps)
To exclude them from the home:
• Install screens, use weather stripping where appropriate
• Seal or caulk cracks and crevices around the house
• Use screens over pipes and other access points
• Use yellow or sodium vapor lights outside
• Locate all-night exterior lights away from home
• Tape edges of storage boxes
• Use Sealed plastic bags to store loose items in garage, attic, basement, or other dark places
Practice good sanitation around the home:
• Remove trash, old boxes, clothing, rock piles
• Eliminate cluttered closets, basements, attics, garages, etc.
• Store items off the floor, away from walls (basements, crawl spaces, garages, outbuildings)
• Do not stack firewood against house
• Remove heavy vegetation and leaf litter around house foundation
• Wash spider webs off outside of the home using high pressure
Use nonchemical control:
• Capture spiders, release outside
• Dust, vacuum thoroughly (get rid of debris)
• Use broom or water hose to destroy indoor webs
• Use rolled newspaper or fly swatter to kill spiders
There are many insecticides labeled for use to kill spiders, but these do not destroy egg sacs. There are aerosol sprays, dusts, powders, and liquids. Only use chemicals as a last resort.
For more information go to http://go.osu.edu/spider.