Black Widow spider

I get many calls from people wondering what can be done to minimize the presence of Black Widows? First I have to say, because spiders are small it is hard to totally eliminate them. However, there are some things you can do to cut down their numbers and protect yourself.

-Regularly sweep and vacuum corners and other dark spots, low and high, inside and out. Outdoors you can spray these areas with the hose.

-Frequently check under lawn chairs and picnic tables as well as under children’s molded plastic, pedaled toy vehicles that have open areas facing down that a spider might find inviting.

-Don’t leave food out that might attract insects, the spiders’ prey.

-Keep gardening gloves and other clothing normally kept in the garage or storage shed in sealed containers or ziplock bags.

-Try to keep windows and doorsills, places where spiders can enter the house, sealed with weather stripping.

-Some people claim mothballs or Osage Hedge balls as being effective in killing or driving spiders away.

-Don’t bring them indoors on firewood or plants.

Chemicals are not overly effective as, in regards to spiders, they don’t have much residual effect and are harmful to other animals, pets and people. If you are not comfortable hunting spiders and killing them, you can always trap them in a jar and relocate them, Usually a few hundred feet from your house in a suitable habitat is plenty of distance. And, no, relocating them in your annoying neighbor’s garage is not an option…

For the most part, however, spiders are actually very helpful; they are the most important insect predators in the world. But, a lot of people just don’t care about all the good spiders do for us. To these people, the only good spider is a dead spider.  Thankfully (at least to avoid being overrun by insects) spiders are very prolific. A single acre can have a population of spiders ranging from 10,000 to 2,000,000!

Along with their prolific nature one other spider behavior makes keeping them under control a problem. This is from the University of California, Davis’ web site:  “One aspect that makes controlling widow spiders difficult is that they, like many spiders, exhibit a behavior called ballooning. When the spiderlings are very small, on warm days when there is an updraft, they climb to the top of a fence post or piece of vegetation, raise their abdomens into the air, and release a small filament of silk.

When the updraft currents overtake the forces of gravity, the spiderling is carried into the air to another location. This may only be a few feet away, or it could be miles. Ballooning spiderlings have been captured at 10,000 feet from the ground and 200 miles offshore. Because spiderlings will be dropping down on your property continually, eliminating them will be a task that needs to be done repetitively throughout the year.”

If you have questions about local bugs feel free to contact us and we will offer what information we can or direct you to other good sources.

Kathy Maguire
Curator of Amphibians and Invertebrates

What Can I Do About Black Widows Around My House? is a post from: Scales & Tales

Black Widow showing belly marking, not always a perfect hourglass.

As warm weather approaches, we start getting calls about spiders and odd bugs people find in their garages, storage sheds, yards, and houses. The most common calls we get are in regard to spiders, especially black widows, brown recluse and a mysterious GIANT! spider that seems to strike fear in all who see one. The latter would be the common wolf spider.

Out of the tens of thousands of spiders in the world, only a few are dangerous to humans. The most common dangerously venomous spiders in the US are the Black Widow, the Brown Recluse, and the Hobo spider – and they rarely bite people. Far more people die each year of bee and wasp stings that from spider bites. And by the way, it is just a myth that the common daddy longlegs spider is extremely deadly – there is no scientific evidence to back up this fanciful tale.

One common spider in our area that you need NOT be overly concerned with is the aforementioned Wolf Spider. These large, furry spiders come in a wide variety of colors and do get quite large. They are not really tarantula sized but may look that way if you happen upon one in your house. They rarely bite and their bites are not normally life-threatening but can cause adverse reactions, like pain, redness, and swelling, in some people.

A nice big Wolf Spider

Once things warm up one of the most common larger spiders in our area is the orb weaver. This is a big family of spiders. Orb weavers come in many shapes and sizes and are relatively harmless to humans. The orb weaver most commonly seen around here is brown, tan, or light rust color, is about the size of a dime, and has a large bulbous abdomen with little points on it. Their spiral-shaped webs are often seen along the eaves of houses and around porch lights where their prey, insects, are drawn.

A common Orb Weaver

Another Orb Weaver

Another very different form of orb weaver is what is called the garden spider or black-and-yellow argiope. These big spiders weave beautiful and large, classic-looking webs with heavy zig-zags running up and down the center which act as stabilizers. They are called garden spiders as you most often see them in the garden, between bushes, or in tall weeds where there is enough room for their big webs and where insects are common.

Argiope or Garden Spider

Although not native to our area, there have been local accounts of Brown Recluse spiders – possible bites from them have been treated at our local hospital. In our mobile society, these may have been stowaways when people move to this area from regions where the recluse is common. It is not known if there are any stable populations here at this time. This is a relatively small and delicate-looking spider. They are also called fiddle-back spiders due to the violin-shaped pattern on their backs.

Brown Recluse Spider aka Fiddleback Spider

For the most part, the only spider we need to be concerned with in our area is the Black Widow. There are 5 varieties of Black Widows in the US and Canada with various types  of markings. But, the most obvious identifier is the large, shiny, black, round abdomen with a red (or sometimes yellow) hourglass on the underside. Young Black Widows are brown with cream-colored markings on the abdomen. This spider gets its name because the female reputedly has the habit of eating the male after mating if he doesn’t run away quickly enough. The male is much smaller – too small to inflict a dangerous bite to humans.

Black Widows are common in our area but stay hidden most of the time. They frequent basements, garages, sheds, trash piles, and outhouses; just about any quiet dark corner will do. They may also find their way into clothing and shoes making it a good idea to look before ‘slipping into something more comfortable.’

The female spins an irregular shaped, strong, and very sticky web, then spends most of her time hanging upside-down waiting for unsuspecting insects to drop by for dinner. A Black Widow will do her best to stay hidden in a remote corner of her web.  If bothered, she will try to run away. Biting is only a last resort if she cannot escape.

Because of her toxic venom, the bite of a Black Widow can be very dangerous to humans and animals. Within minutes of being bitten the most notable symptom of a Black Widow bite begins, extreme pain develops around the bite. This pain builds rapidly in intensity in the 30 minutes following the bite. Other symptoms develop as the powerful venom begins to work on the nervous system. None of these are much fun either:  nausea, vomiting, dizziness, and fainting are accompanied by an increase in salivation, watering of the eyes, and profuse sweating.

Black Widow spider

If the bite remains untreated, speech may be affected, breathing becomes difficult, and the jaw muscles go into spasms, which distort the face into a pain-racked grimace. Muscles all over the body go rigid, especially those in the midsection, which may pull so tightly doctors have incorrectly diagnosed a spider bite as appendicitis or ulcer. Youngsters and older people are, of course, most at risk.

Fortunately there is an antivenom for a Black Widow bite. Once administered, the antivenom usually works quickly to neutralize the venom. Research has shown that the venom of the Black Widow is 15 times more potent than rattlesnake venom. No one is certain why such a little spider needs such potent venom to survive. Yet another example of Nature’s overkill I guess.

And those reptile guys keep telling me I just take care of the “harmless animals.”

Kathy Maguire
Curator of Amphibians and Invertebrates

It is Spider Season! Black Widows and their Friends. is a post from: Scales & Tales