Utah's Top Spiders

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Did you know that Utah is home to more than 600 species of spiders and that almost all of them are somewhat venomous? The majority of these species have too weak of venom to harm a human but a few can be quite dangerous, especially to children, elderly or those with weakened immune systems.  It is important to know the differences between these spiders and how to keep them away from your home.

Black Widow

    The black widow is considered to be Utah’s most venomous spider.  The females are typically half an inch long which is double the size of the males.  They have a black, shiny coat with a very distinctive red hourglass marking on the underside of their abdomen.  Although it is most common to have the red marking there are some without, mostly males or immature females.  Black widows are primarily a nocturnal species, thriving in cold, dark places.  They are prone to spin their webs in areas of low activity such as a garage, shed, dark crevice, and under piles of wood or other debris.  We most commonly find them lurking around the sensors of garage doors.  

If disturbed the female black widow will bite, leaving two small holes from her fangs.  Venom from a black widow attacks the victims nervous system and if not treated can be life threatening.  Symptoms will usually appear within 20 minutes to an hour.  You may experience but are not limited to vomiting, muscle spasms and/or cramps, pain and numbness, abdominal pain, nausea and dizziness, difficulty breathing, and/or shock.

Brown Recluse             

    The brown recluse spider, also known as violin spider can be identified by its light to medium brown color and distinctive markings on its back and neck resembling the shape of a violin.  They thrive in dry, hot climates, making Utah an ideal place for them to live.  They are extremely resilient and can tolerate up to 6 months of drought and starvation. If you get close enough you will be able to see that they only have 3 pairs of eyes rather than the typical 4 pairs that other species of spiders have.  However, we don’t recommend getting too close to these spiders.

The brown recluse bite can cause the skin around it to become necrotic and can take several months to heal resulting in deep scars.  They like to build their webs in dark areas such as under wood piles or rocks.  They can also be found in places such as attics, basements, and garages preferably were cardboard can be found, thought to resemble rotting tree bark.  Be sure to use caution when moving objects in these areas that have sat for an extended period of time.


Hobo Spider

    Another species common to Utah is the hobo spider.  They are not as easy to identify as the black widow or brown recluse.  The hobo spider is light tan to light brown in color and has faint darker brown markings on its abdomen and head.  They are known for their speed but are not very good climbers making it so they are not commonly found above ground level.

Hobo spiders are also referred to as a funnel spider because of their funnel shaped webs.  They prefer the outdoors and because they are more on ground level, you will typically find them in window wells, rock piles, foundation gaps, basements and other protected, undisturbed areas.


Wolf Spider

    Commonly mistaken as a Tarantula due the their size (some as large as 2 inches) and hairy texture is the wolf spider.  They get their name because like wolves they are hunters.  Instead of spinning webs the wolf spider will stalk and ambush their pray by pouncing on them for the kill.  Also making them good hunters is their excellent eyesight, with 2 larger dominate eyes in the middle row, 4 on the lower row and 2 on top of their head. 

Wolf spiders coloration can vary on where they live.  They can typically be found in open areas such as fields or grassy areas making them depend on camouflage for their protection.  Unlike other species the mother with often be seen with offspring on her back for multiple weeks until the babies are strong enough to go off on their own.

Although wolf spiders are considered one of the most dangerous species and their bite is very painful, it is not lethal. If bit there is often pain, redness and swelling that can last up to 10 days and can cause further complications if not properly cared for.


Yellow Sac Spider

    The yellow sac spider gets its name from its bright yellow coloring.  They are smaller than some of Utah’s other species growing to about .25 inches and their front two legs are significantly longer than the other six.  Although they prefer the outdoors they are known to sneak indoors when the weather starts to cool.  During the day they will hide in flat sack like webs usually in the corners of your baseboards or ceiling and will become more active at night.

Venom of a yellow sac spider is not as harmful to humans as other species such as the black widow or brown recluse.  If bit you can expect to experience redness, swelling, burning, itching, and pain.  Most symptoms can last for a couple hours.


Woodlouse Spider

    Another common spider in Utah is the Woodlouse.  It can be easily recognized by its vibrant red head and legs and yellow to cream colored abdomen.  Woodlouse spiders are known for their abnormally large fangs.  They use their large fangs to their advantage when attacking their prey.  The woodlouse spider will prey on earwigs, crickets, millipedes, and most commonly woodlouse (more widely know as the potato bug) thus giving them their name.

Woodlouse spiders prefer dark moist areas such as under rocks, wood piles, and basements. They like to hunt at night and do not spin webs.  Their venom is not known to be harmful to humans but due to their large fangs can be very painful if bitten.  It can cause welts, rashes and/or irritation around the bite.  

Dangerous or not, spiders are not something you want to be sharing your home with.  For help eliminating your chance of crossing paths with one of these or many other species, give Bug Off Pest Control a call.  Our licensed technicians can help locate potential problem areas to prevent these pests from invading your home.  Let us use our knowledge and experience to help keep you and your loved ones safe.


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