St Louis Pest Control Blog

St. Louis Pest Control – Brown Recluse Spiders

Fall is a great time of year, but colder temps tend to bring more pests into our homes as they look to stay warm, and look for possible food sources.  This influx of pests also causes an influx of spiders looking to follow their food sources onto or into our homes for the winter.  At Blue Chip Pest Services this is a time of year almost as busy as the spring thaw in April and May.

Most spiders are pretty harmless, and actually benficial to have around as they eat other pests.  Certain species of spiders however are not so welcome.  The one in particular for this part of the country is the Brown Recluse Spider.  The brown recluse spider gets its name from both its color and it behavior.  They tend to stay hidden most of the time, and only come out to feed.  The “reclusive” behavior makes them not particularly easy to find all of the time.

The reason that they are not welcome is the fact that their bite is very dangerous.  The venom causes a necrosis of the skin or deadening that may require surgery to correct.  I will not post pictures of it here because of the graphic nature of them, but they are easy to find on the internet.

They are identified by the “fiddle” shaped spot on their back.  They are light brown in color, and the spot is noticeable darker that the rest of the spider.  They are a little larger than the size of a quarter with legs extended and are not particularly hairy.


They are often confused with the hobo spider, which will have two lines on its back that may appear to be wavy like the fiddle, but there is no definite “spot”.

Control of these pests is not difficult, it is however tedious in that you must treat all entry points into the home as well as any areas that they may use as a harborage either inside or outside the house.  Control is also achieved through harborage reduction both inside and out.  Things that can be done include:

  1. Remove leaf piles from outside the home.
  2. Seal cracks and crevices around windows and doors.
  3. Make sure doors and garage doors seal tightly.
  4. Eliminate as much cardboard as possible from inside the home or garage.
  5. Seal clothes in plastic bins so that spiders don’t move into stored clothes or shoes.
  6. Place stored items in garage or basement on shelves and slightly away from the wall so as to allow air flow between stored items.
  7. Dust and knockdown webs regularly to force spiders onto treated areas.

Most bites occur when someone puts on either clothes or shoes that a spider has taken residence in, and they bite in response to being trapped / pinned by us.  Always shake or launder clothes before wearing them after long periods of storage or non-use.

Our regular pest prevention programs focus on the outside of the home to prevent their access in the first place to the home.  Treating under siding, into cracks and crevices, around windows and doors, even out into the yard around bushes and other plants.  If we do need to treat inside, spraying baseboards is a waste of time except in storage areas, basements, garages, and closets.  Materials must be placed into the hiding spots for these pests not onto long open spaces.

Please call us if you have any questions or concerns regarding these pests at 636-343-7900 or go to for more information regarding our service options.


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