Venomous Spiders
RSSI Safety Minute
https://northwesternrssi.wixsite.com/rssi
Identifying Venomous Spiders
Black Widows (Latrodectus mactans, hesperus, & variolus)
Brown or black spider with large, round abdomen. Characterized by the red hourglass on the ventral abdomen; occasional red, yellow, and orange dorsal and caudal abdomen markings. Produces cobwebs near the ground (usually below waist height) in undisturbed places, and often hangs upside down in their webs. Produces neurotoxic venom (α-latrotoxin)
Brown Recluse (Loxosceles reclusa)
A large pale tan to brown spider. Has violin-shaped marking on the back of their head, but characterized by 3 pairs of eyes arranged in a horizontal arc. Usually hides in debris and objects, emerging at night to hunt. They can run quickly and will only bite when trapped and pressed against the skin (e.g. in clothes). Produces necrotic venom (sphingomyelinase D)
Black Widow photo credit: Christopher Sharpe. The rest: https://en.wikipedia.org/wiki/List_of_medically_significant_spider_bites, https://en.wikipedia.org/wiki/Latrodectus, https://en.wikipedia.org/wiki/Brown_recluse_spider, �https://en.wikipedia.org/wiki/Phoneutria, https://en.wikipedia.org/wiki/Australian_funnel-web_spider
Non-N. American Very Venomous Spiders
Brazillian Wandering Spider (Phoneutria nigriventer)
Very large (5-7”), very venomous, accidentally shipped with bananas
Australian Funnel Web Spider�(Atrax robustus & others)
0.5-3”, aggressive, and wander�Has the most potent spider venom
Handling Spiders
https://www.wikihow.com/Catch-a-Spider, https://wildspotter.org/
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If it is an invasive species, keep the live/dead spider and report it to the USDA Forest Service using the Wild Spotter app
Most spider bites are “dry” (no venom injected) or from species that do not harm humans.
However, more significant symptoms can occur:
In all serious cases (when symptoms exceed minor swelling and redness), the CDC recommends that you:
https://www.cdc.gov/niosh/topics/spiders/symptoms.html
Spider Bite First Aid