Before spraying for spiders, let’s look at a few facts. Outdoors, they’re an important part of the food chain. Indoors, their presence is not appreciated. With the right information we can begin to rethink some of our fears and misunderstandings about spiders. This article will help us make the right decisions for pollinators & wildlife. Let’s look at a few techniques on how to make peace with the spiders around your home.
Spider Fun Facts
- There are over 45,000 species of spiders recorded worldwide.
- For reference there are only about 6,500 known mammal species of any size, shape and species.
- Spiders can live underwater, in the driest deserts on earth, and 25,000 feet up on the side of Mt. Everest.
- Spiders have an amazing ability to “balloon” or travel airborne via small silk sails on wind gusts.
They’re able to float hundreds, even thousands of miles this way to find new habitat and continue to evolve. I have heard and believe in my heart, that you are never more than ten feet from a spider. It’s since they are so abundant we often go spraying for spiders. Their ever lurking presence often causes calls to the exterminator.
How Long Do Spiders Live?
In general, spiders live about two to three years naturally. Their life span often depends on the species, habitat conditions and the amount of insects and other invertebrate food they’re able to find. Spider with better food and more suitable habitat are often able to live longer than smaller, malnourished spiders.
So first things first before we go spraying for spiders. In the Portland area, no spiders are known to cause necrotic harm to humans besides black widows. Brown Recluse (loxosceles reclusa) is one you’ve maybe heard of. Brown Recluse is potentially dangerous, but is native to the Southeastern US and doesn’t survive well in our colder rainy climate. Its possible that sometimes folks find them here due to transportation by vehicle, wood storage, etc.
Black Widow Spiders
In Portland Oregon black widow spiders (latrodectus hesperus) are not common. In Eastern or Southern Oregon they are slightly more common, but still not at all likely to harm you. They live in undisturbed crevices under rocks, logs and in dark hiding places. Even if your full-time job is to thoroughly inspect dark places to conduct spraying for spiders like me you’re not likely to find one.
False Widow Spiders
Despite my best efforts I have never seen a black widow spider in Portland. False Widow Spider (steatoda grossa) is a notable look alike that is actually VERY common. Carefully inspecting crawlspaces I compulsively check every false widow spider for the distinctive red hourglass. Never in my career have found an actual black widow in the Portland area. Hopefully this helps you make peace with spiders around your home.
Spiders creep humans out on the deepest levels of evolution. Especially this next species. By far our worst offender of blatant outward creepiness is the giant house spider.
These are the thick fuzzy dark-brown or grey-black massive chonkers. They’re very docile until you come at them with the paper and cup. Then they come running straight at you. Adults are about the size of a quarter. This is a fun species that arachnologists have flip-flopped back and forth on whether it is three distinct species; Eratigena atrica, e. duelica or e. saeva, or just one inclusive species e. atrica.
Harmless However Horrifying
I have racked up hours of staring in fascinating disgust at various house spiders. Or poking them (in full protective equipment) with any object (not my finger). There can be lots of different sized house spiders, but some of them get huge. They can appear frightening or too big to squish. They come running RIGHT for you. How do you deal with this unfazed menace?
It’s always good to remember they almost certainly won’t hurt you. Sometimes the overturned cup trick doesn’t work or is too risky of a procedure. Some folks are unable to physically remove spiders of this size, I understand. For those folks, consider busting out that old can of aersol bug killer. By spraying for spiders with one direct hit from an aersol can, you will nail your target. It may even be a more ecologically sensitive approach than having a recurring professional treatment that sprays for spiders on the outside.
For more information about Oregon spiders, check out this document published by Oregon Department of Agriculture.
Hobo spiders (tegenaria agrestis) can be found in Portland Oregon. They’re in the aforementioned family of house spiders. Hobo spiders, like others spiders in our area are considered harmless.
Tegenaria agrestis actually refers in latin to the fields in which they would be found. It does not refer to aggressive behavior since like most all spiders they stick to dark corners. Most of our house spiders are simply hunting insects & other wayward arthropods and avoiding predators like birds and amphibians.
Barn funnel weavers (Tegenaria domesticus) and wolf spiders (Pardosa sp.) are other scary hairy but harmless creepy basement intruders. Like other spiders they shouldn’t be feared. They’re not likely to harm or ever contact you. They may even be picking off random pests like flies, moths, silverfish or dermestid beetles.
Yellow Sac Spiders
Yellow sac spiders (Cheiracanthium sp.) are a common Portland home dwelling spider. They’re the tiny spiders that hang out in stringy cobwebs in the top corners of your ceilings. They’re translucent yellow, green or pale white in color and about 1-3 millimeters in size.
Easily knock down these cobs while you’re regularly sweeping or vacuuming. Do so once every fortnight as the summer transitions to fall. I have been told that the yellow sac spiders are actually the most likely to cause an itchy or painful bite. Hopefully it reassures spider skeptics that even if it itches, yellow sac spider bites aren’t known to be harmful.
Green Spider Management
I’ve had lots of folks tell me to “go nuts” spraying for their spiders. Most people call pest control intending to eliminate spider sightings in the home. Candidly, even with the most advanced 21st century chemical pesticide spraying, seeing zero spiders shouldn’t be a realistic expectation. But there’s lots you can do to make your house less hospitable for spiders. Follow these Integrated Pest Management tips to stop unnecessary spraying for spiders & actually see less of them.
Reduce Spiders Living in the Home
Start by pulling storage boxes & totes a foot or so away from the base of the walls. Secondly lift items off the floor onto a wire storage rack or non-porous shelf. The goal is to reduce the amount of tiny dark cracks, secluded corners and crevices where spiders hide and lay eggs. If spraying for spiders is deemed necessary, it will also allow your pest management technician to perform a more thorough treatment.
Vacuum Instead of Spraying Spiders
More effective & infinitely greener than spraying spiders is vacuuming them and their webs. Inspect once a month and use a dust buster or vacuum cleaner hose attachment to suck up any visible webs and spiders. Check the dark corners of your pantry, closets, basement, under furniture. Pay extra close attention to the intersections of your walls & ceiling where pesky cob-weavers can hide. Sweep outside webs with a broom or web brush on an extension pole to manage orb-weavers in the fall.
All Natural Spider Repellents
Self-treating with all natural spider control products may provide some relief. To learn more check out our article about the pros & cons of some ingredients of all natural spider repellents.
Spider Trapping Techniques
Glue boards aren’t great for mice & rodents, but they’re awesome for helping reduce spiders without pesticides. Place assembled glue traps flush along the basement walls and under shelving or furniture. This way you can trap any spiders while they’re hunting around, following the baseboards.
Where Do Spiders Live?
Reducing outside spider habitat will help prevent an influx of spiders coming inside. Many spider pest species like to hide and live under piles of wood, brick, lumber, masonry, leaves and downed limbs. They also live in sheds and old play structures where they lay their eggs and hunt for insects and arthropods. Cleaning up or finely mulching yard debris is a good first step. Having native plants in your habitat will encourage birds which are predators of spiders.
Before Spraying For Spiders…
Before you start spraying for spiders, be aggressive with habitat modification. Remember spiders will always return to favorable hiding places no matter what spray or spider repellent is used. The best all natural spider control always comes from a good Integrated Pest Management (IPM) strategy. Click here to read more information about IPM & how to get the best pest control for spiders.
Integrated Pest Management (IPM) for Spiders
Consider removing old sheds, fire wood, unused outbuildings or infrastructure. Plan for any new structures to be simple in construction and minimally contacting the side of your home. Removing invasive or non-native trees and shrubs can reduce spider habitat and encourage more spider predators.
Keep It Dry & Tidy
Lastly, mow the lawn on the lowest setting as often as you see it growing. Hold off irrigating until the first three quarters of an inch of the soil is completely dry. Consequently this can prevent fungus gnats, flies, and arthropods from becoming food for pesky outdoor orb weaver spiders. Allowing the soil to dry slightly will also help with mosquitoes and crane flies.
Areas of excessive moisture often lead to human pests like spiders, mosquitos, centipedes, fleas and others to thrive and breed. So it’s important to identify and remediate any areas that are prone to ponding or becoming waterlogged. Rain gardens, xeriscaping, and native plant installation are all excellent ways to manage nuisance spider populations in the backyard. Having a healthy ecosystem is how best to make peace with the spiders around your home.
Here in the rainy Northwest, our mild climate can be a beautiful blessing. Because of it we enjoy lush plants and abundant wildlife. It is here in this abundance where our responsibility is greatest. Pest & Pollinator specializes in finding creative ways to get rid of Portland spiders while thoughtfully managing hazard to pollinators & wildlife. Click here if you’re interested in learning more about Portland pollinator safe spider management options.