Peak spider season is coming to eastern WA. Watch out for these two venomous species

KENNEWICK – The end-of-summer transition to cooler weather in Eastern Washington is often accompanied by an influx of spiders.

Over the next few months, you’ll likely notice a significant increase in spider activity.

Spiders are more active during this time, their mating season, making themselves more noticeable.

Experts estimate there are hundreds of spider species in Washington. Most pose no threat to humans, lacking enough venom to really hurt someone.

There are two species of “medical concern” in the state, according to the Washington State Department of Health, the black widow and the yellow sac spider. Both are common in Eastern Washington.

Some arachnologists, like Rod Crawford, curator of arachnids at the University of Washington and curatorial associate at the Burke Museum, believe the yellow sac spider is not dangerous and should no longer be referred to as such.

Venomous spiders in Washington

It is important to note that spiders are venomous, not poisonous. Something that is poisonous causes harm when ingested or touched, like mushrooms. Something that is venomous injects toxins, like a snake or spider.

It should also be noted that most spiders are venomous, and “medically significant” species are just the ones whose venom can cause localized pain in humans. Spider venom is meant to subdue their prey, insects, not humans, so few species can harm people.

Black widow spider: The western black widow spider is native to Eastern Washington. The females can cause a painful bite for humans if protecting their eggs, according to the state Department of Health. These female spiders don the notorious black widow look, with long, black legs and a red hourglass on its abdomen.

These spiders can be found in dark, undisturbed areas. It’s a good argument for keeping your house clean and vacuuming behind the couch.

These spiders are one of the only problematic spiders in Washington since a bite from a black widow can cause serious symptoms such as severe muscle pain. Seeking medical attention is highly advised if bitten by one.

Yellow sac spider: Yellow sac spiders can be yellow, white or green with darker legs and abdomen. These spiders mainly live outdoors in gardens, but will travel inside during cold temperatures and are known to build sac-shaped webs in corners or ceilings.

Yellow sac spiders tend to be more aggressive, but a bite from one, although painful, is generally harmless unless the person is allergic.

Helpful spiders in Washington

Even if you aren’t a big arachnid fan, consider thinking twice before sending an indoor bug outside or stepping on a spider in your garden. Once you’ve ruled out a venomous spider, chances are that the creature helps you a lot more than you realize.

The most common spiders seen during this time of year are cross orb weaver spiders, which live outdoors, according to Crawford. They are often seen in the Tri-Cities’ many riverside parks.

“Considering spiders as a whole, it’s not spider season, but considering (cross orb weavers), the ones that people actually notice, it is their season,” Crawford said in a previous interview for McClatchy.

They feed on the insects and pests along the river, like gnats and aphids. Their large webs capture the creatures as they mature. If it weren’t for spiders, there would be a lot more of these small, often considered annoying, flying insects.

Benefits of spiders in Washington

Although you might’ve been trained to think that spiders are out to get you, that isn’t true, and even having house spiders around could be beneficial. Spiders do not prey on humans. They are the leading predators of thousands of insects. House spiders are no different as they prey on the insects inside of your home. They insects they prey on include:

• House flies
• Fleas
• Bed bugs
• Carpet beetles
• Clothes moths

Spiders are a large benefit for your garden, too. The average pesticide-free garden in Washington is home to around 20 to 25 spider species, according to a Washington State University – Tri-Cities publication.

“Spiders generally evoke negative emotions in people, but you should truly be grateful for their presence in your garden,” the publication states. “The pest control services that spiders provide is enormous and greatly underappreciated.”

The many spider species occupying any given garden are feasting on the insects that can wreak havoc on your produce and other plants. Some of the many pests they feed on include aphids, mites, leafhoppers, whiteflies and thrips.

When to seek medical attention for bites

You might be happy to know that spider bites are rare and in the instance that a common spider bites you, its small dose of toxins will not harm you.

A spider bite will cause a small red bump that is no bigger than a mosquito bite. People are advised to clean the bite with warm soap and water as well as rubbing alcohol to keep the wound from getting infected. The red bump should disappear in one to two days.

If the bite doesn’t heal within two days and it begins to look more like a blister, seek medical attention.

Allergic reactions to spider bites

It is possible for people to have an allergic reaction to a spider bite including anaphylactic shock, according to the Washington State Department of Health. Seek immediate medical attention if you have any of these anaphylaxis symptoms:

• Chest pain
• Face or mouth swelling
• Difficulty swallowing and breathing
• Fainting or lightheadedness
• Abdominal pain or vomiting
• Rash or flushing