WSU Extension

Pestsense

Spiders (non-biting)

(revision date: 1/11/2019)


Use Integrated Pest Management (IPM) for successful pest management.

Biology
To say spiders don’t bite would be in error, since all spiders bite their prey. Most spiders, particularly small species, have not been seen biting humans. However, these 8-legged creatures can be quite a nuisance. The most common nuisance species are orb weavers which construct their vertical webs in the most inconvenient places – in front of entries, over paths between shrubs, in front of windows, etc. Furthermore, their constant defecation can dirty up decks and other surfaces to the extent of making them unsightly. Remember all spiders feed on insects and their relatives so we should consider them beneficial. For more information, see the following publication: Common Spiders of Washington (EM113E) at http://pubs.wsu.edu.
Management Options

Non-Chemical Management
  • Orb weaver spiders commonly build their webs across backlit windows. This encourages flying insects, which are attracted to light, thus providing the spiders with food. Diminishing such light sources at night will help discourage spider build up on windows.
  • Use of mechanical devices such as fly swatters, shop vacs, brooms, etc. will help keep their numbers down. Remember, tolerance is also an option.
Select non-chemical management options as your first choice!

Chemical Management

None recommended.

Images
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Caption: Orb weaver
Photo by: Art Antonelli