It's that time of year again.  The air begins to take on a crisp coolness and the vivid fall colors begin to show.  Thoughts turn to harvesting as the summer heat fades away.  This is the time of year when you are most likely to see uninvited and unwanted visitors wandering in from outdoors to take up residence in your warm, cozy home.  I'm referring to our arachnid friends - the spiders.

To most people the mere thought of spiders conjures up fear and a feeling of the "heebie-jeebies."  Spiders rank just behind bees and wasps as the most feared arthropod. Some people just do not like the way spiders look; others have heard unsubstantiated myths about spiders. Few welcome these beneficial visitors.  A spider's diet consists exclusively of insects and other arthropods. Spiders are a very efficient and important form of biological pest control.

The most common types of spiders seen indoors are the funnel web spiders, cobweb spiders, cellar spiders, jumping spiders, wolf spiders, and sac spiders.  Funnel web spiders, or grass spiders, produce silken webs with a central retreat, the "funnel."  They are harmless but are frequently mistaken for the potentially dangerous brown recluse.  The funnel web spider has a darker brown color and black markings on the abdomen, whereas the brown recluse has the distinctive violin-shaped marking on the top of the front body section.   Cobweb spiders or house spiders commonly live in dark corners around the home.  Their bodies are bulbous and they create messy, sticky webs.  Most all cobweb spiders are harmless with the exception of the potentially dangerous widow spiders.  Jumping spiders are active colorful spiders that, as their name implies, jump to ambush their prey. They do not produce a web.  They are nonaggressive and harmless.  Wolf spiders are also active hunters.  Their coloring ranges from grey to brown and they can be very large, as is the giant wolf spider.  Most are smaller and look similar to the funnel web spider.  They are normally shy and not dangerous although the larger species can bite. The sac spider is an active hunter that spends its days in a flattened silken sac usually located in the upper corners of rooms or wall cracks.  Most of these spiders are a pale color.  The bite of the sac spider can be misdiagnosed as a brown recluse spider bite.   Reactions, such as swelling, slow healing and ulcerated sores around the bite site are similar to that of the brown recluse but are much less severe.

There are a few potentially dangerous spiders that can be found in the home.  These include the widow spider, brown recluse, and hobo spider.   The widow spiders are common in Colorado.  The presence of a red or red-orange marking on the underside of the abdomen is a characteristic of this spider.  The pattern may appear as an hourglass or two separate triangles.   It can be vividly colored or faint.  The color of the adult female is a shiny black.  Widows usually like to make their home near the ground in dark, secluded places such as entrances to crawl spaces, window wells, sheds, firewood piles and corners of garages and basements.  Bites usually occur when the female is provoked.  The bite is painful and potentially dangerous because the venom contains a nerve poison.  Symptoms can include dizziness, shortness of breath, painful abdominal spasms, rigidity of limbs, increased blood pressure, and profuse sweating. An antivenom to the black widow bite is available.

The brown recluse spider is rare in Colorado.  It has been nicknamed "fiddleback" because of its distinctive violin shaped marking found behind the head.  These spiders are pale brown with long dark brown legs.  The brown recluse avoids areas where there is activity, preferring closets, guestrooms, basements and attics.  The initial bite of the brown recluse spider is usually painless followed by a local burning sensation within the first hour.  Within the next 6-12 hours a small blister forms.  The tissue surrounding the bite begins to look darkened and raised in appearance.  During the next 10-14 days an extensive necrotic reaction can occur and form a sunken, open, ulcerated sore several centimeters in diameter.  The healing process normally takes from 6-8 weeks.  The hobo spider is a European species of funnel web spider that was recently found in Colorado.  Reports indicate that the bite of the hobo spider is similar to that of the brown recluse.  If you suspect a spider has bitten you the American Red Cross gives these first aid steps:

1. Treat the site of the bite with an antiseptic to prevent infection.

2. Apply ice to the site of the bite to reduce pain and swelling.

3. If a black widow or brown recluse spider is suspected or if serious symptoms develop such as increasing pain or swelling, consult a physician.

If possible, bring the offending spider to the physician's office for proper identification and diagnosis.

The best way to keep spiders out of your home is to limit their access.  Remove debris and wood piles from around the home.  Seal cracks and crevices in the foundation, in walls and around doors.  Limit boxes and potential hiding places in basements and storage areas.  Regularly vacuum spider webs around the home near baseboards and under furniture.

For further information, see Fact Sheet #5.512 - Spiders in the Home.

Q: My container plants were great this summer and I hate to let them go, can I bring them in?

A: You certainly can but there are a few things to keep in mind.  Your plants have adjusted to the outdoors and they would have to adjust to being inside. Check daily to be sure that they are receiving sufficient light and water. There is also a chance that when you bring a container inside you may bring along bugs such as aphids and white flies.  These can infect other plants in your house.  Spraying with an insecticidal soap can help eliminate this problem.

Q: I have noticed that my ash has some branches that I would like to remove, when is the best time?

A: You can remove dead branches any time but the best time to prune live branches from most trees is in the late fall and winter when the tree is relatively dormant. If you have a large mature tree, you may want to hire a certified arborist to safely do the work. If you are pruning a smaller tree yourself, be sure and make proper pruning cuts. For help in this, request Fact Sheet #7.207 Pruning Deciduous Shade Trees by calling the Larimer County Cooperative Extension office at (970) 498-6000 or download the fact sheet from our web site at www.larimer.org/ext  Go to horticulture and gardening fact sheets.

Q: I grew gourds in my garden this year, when should I harvest them?

A: Gourds do take a long time to mature and if you pick them early there is a chance they will rot.  They need to develop a hard shell so leave them on the vine until the vine withers and dies.

Q: My tulips didn't bloom well this year. What could be the problem?

A: This would be a good time to dig them up and take a look at the bulb.  If they have become soft they are rotting and are best discarded.  It is also possible that they need to be divided. If they have "bulbettes", little bulbs that grow off of the parent bulb, break them away from the parent bulb and plant them individually. Add a super phosphate fertilizer to your planting hole before you plant to encourage root growth.

“Flagstone” comes from any type of horizontally layered rock that can be split into flat slabs or “flags.”  Artificial flagstone is made with concrete dyed the color of natural stone and cast into slabs.  The flags should be 1” to 2” thick for paving.  A small path for one person can be 18” wide but a path for two people to walk side by side should be 4’ to 5’ wide.

Bark beetles are small, cylindrical beetles that breed under the bark of trees.  They can spread diseases and kill trees.  Outbreaks are the result of drought, lightening, severe storms and human activity that lead to unhealthy forests and trees.  The mountain pine and Ips engraver beetles favor pines and spruces while the banded elm bark beetle, just discovered in Colorado in 2003, has become a major problem on elms.

Harvest baskets come in handy now when you’re trying to get everything inside before frost.  Bushel baskets are good for apples, corn, melons, potatoes and squash because they hold a lot.  “Trugs” are flat and great for carrying crops that shouldn’t be bent or crushed.  Use them for asparagus, fresh-cut flowers, peaches, berries or tomatoes.  Wire baskets are designed for root crops like beets, carrots and turnips.  You can rinse off the produce right in the basket.

The authors have received training through Colorado State University Cooperative Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County.

Gardening and Insect Fact Sheets are available on-line by clicking HERE.

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This page updated:  September 15, 2003