More on Spiders - Spooky or Friendly?

In light of the Hallowe'en festivities all around us, we will share more information on spiders today, with a look at what makes them spooky and  how we can focus on their more redeeming qualities. Spiders have amazingly bad press. They have been cast as villains in horror movies, murder mysteries, and even fairy tales! The truth is that most spiders are harmless, and extremely beneficial. Part of the delicate balance of nature, spiders eat harmful and nuisance insects in our yards and homes. As noted in this week's bug quiz, only two varieties of spiders in San Diego County can be considered dangerous: The black widow and the desert recluse. Of those two, the black widow is most common. The desert recluse is, as its name suggests, reclusive - preferring to live in remote and unpopulated areas. Bites delivered by these two spiders may be painful, but reactions vary widely and are most often no more serious than a bee sting.  So how can you avoid the scariest spider in San Diego? The more you know about the black widow, the easier it will be to avoid their bites. 

Black widow spiders (pictured above) are shiny, black spiders with thick legs and bulbous abdomens, on the underside of which they sport a distinctive red hourglass marking. Females are around 1/2-inch long, males much smaller - around 1/4-inch, with a longer, narrower abdomen and somewhat longer legs. Black widows are shy, preferring to build their webs in dry, protected locations. Outdoors they are most often found in woodpiles, under rocks, beneath benches, under decks, etc. The web of the black widow is thick, sticky and irregular in shape. If you see this kind of web, use care in knocking it down - although spiders typically have eight eyes, their vision is not good, so they are most often alerted by vibrations. If you encounter black widows or their webs inside (very rare) use a vacuum to remove spiders, webs, and egg sacks - then seal the vacuum bag and discard immediately. Like so many other pests, spiders may be looking for harborage as the weather cools down - so inspect doors and screens to be sure your house is secure. And wear shoes outside! If you are seeing too many spiders in the house or yard, call a pest professional. But remember - spiders eat flies, moths and mosquitos, so as long as they are not bothering you or multiplying out of proportion, let them do their job.

Finally, although we don't see a lot of big scary spiders here, you can rely on videos and news reports from around the world to see the kind legends are made of. Check out the photo and article on a bird-eating spider from Australia here. Take a look at a photo and video of camel spiders here. Or check out the truly scary Monster Spider Web found in Texas here. Enjoy!

Quiz Answers: Spiders!

Pictured: The eyes of a brown recluse spider

Spiders have been big news in San Diego this year. We continue to receive more calls for spiders than usual - indicating a population surge for spiders. Perhaps it is the weather, or maybe more people have been putting out bird seed. Whatever the reason, it is not necessarily a bad thing! The overwhelming majority of household spiders are good for the ecological balance of your yard. Because of the bad press of a scary minority of spiders, it seems the whole group has a bad aura. Here are the answers for yesterday's quiz:

1. The number of spider species that have been identified world wide is (d) 37,000. This is of course an approximate number. But taking that number into consideration, it should become immediately apparent why we are not always able to identify spider samples. What we can do is rule out the most dangerous of local spiders. Which brings us to:

2. The number of spiders in San Diego County which deliver poisonous bites: (a) two. According to the County of San Diego's Pest Management website, "The only poisonous spiders in San Diego County are the Black Widow and the Desert Recluse." From the same source, the Desert Recluse is not the same as the Brown Recluse - and it is found mainly in the Sonoran and Mojave deserts, the foothills of the lower Joaquin Valley and areas close to the Mexican border. Check their excellent site here for more information on these two local spiders with attitude.

3. The largest spiders in the world can be found in (c) South America. In fact,  South American Tarantulas are about the size of a dinner plate - around 12 inches in diameter, with 1-inch fangs. For a video on these "killing machines" see the video here. The good news? Their sting is usually  no worse than a bee sting. There are no reported cases on human death by tarantula!

4. The most  reliable distinction between a brown recluse and a wolf spider is (d) the number of eyes. While it is true that the brown recluse has a dark, violin-shaped marking behind the head (on its cephalothorax), many brown spiders, including varieties of Wolf spider, have markings that could be interpreted as looking like a violin. While the 6 eye pattern of the brown recluse is easy to see with magnification, we do not recommend looking closely at the eyes of a live spider! Some spitting spiders do have a similar eye pattern, but do not have a violin. See the photo above for the distinctive eye pattern of the brown recluse. For more on how to identify the brown recluse, visit the website here. To view a map of where brown recluse spiders are found, see here. Note: The city of San Diego is NOT identified as a brown recluse zone on the map.

5. The largest family of spiders is (a) Jumping spiders (Salticidae), followed by Sheet Weavers (Linyphiidae) and Orb-weaving spiders (Araneidae). Using a well-developed hydraulic system which extends their limbs by altering the pressure of body fluid, jumping spiders can jump 20-60 times their body length as they pursue prey. They typically have eight eyes in two or three rows. Tarantulas are the largest of spiders, but not the largest family of spiders.

6. The best way to avoid spider bites is to (b) wear shoes outdoors. Keeping exterior house doors closed is also a good idea, but unless you are able to close even the smallest breaches under doors and around windows spiders are likely to find their way inside. 

7. The correct FALSE answer is (b) - all arachnids are spiders. In fact, all spiders are arachnids - but not all arachnids are spiders. One case in point is the Daddy-longleg, which is an arachnid but not a spider.

8. This is a trick question. Remember, this is the Hallowe'en edition of the quiz! Depending on what species of spider you were, and how tall you stand proportionally, you might be able to jump (a)85 feet, (b) 130 feet, (c) 260 feet (best answer) or (d) 350 feet. Remember, there are around 37,000 varieties of spiders in the world, with various abilities. Now that you know a little more about spiders, we hope you will not  jump when you see one! For more information in a short video about spiders, click here.

Tuesday's Quiz: Spiders!

Just in time for Hallowe'en, we present Tuesday's Quiz with a focus on spiders this week. Are they the scariest bugs? Certainly one of the creepiest! Test your knowledge of arachnids today and find the answers in tomorrow's blog.

1. How many spider species have been identified worldwide?

a. 1,600

b. 16,000

c. 3,700

d. 37,000

2. Of the many spider species in San Diego County, how many deliver poisonous bites?

a. 2

b. 4

c. 6

d. 8

3. Where would you find the largest spiders in the world?

a. Africa

b. Australia

c. South America

d. Asia

4. The spider pictured above is a Wolf spider, fairly common in North America and often mistaken for the Brown Recluse spider. What distinguishes a wolf spider from a brown recluse?

a.  Brown Recluse are bigger

b. Wolf spiders are nocturnal

c. Brown Recluse have a distinctive marking behind the head

d. Wolf spiders have more eyes

5. The largest family of spiders is 

a. Jumping spiders

b. Orb-weaving spiders

c. Trapdoor spiders

d. Tarantulas

6. The best way to avoid spider bites is to

a. Wear strong perfume

b. Wear shoes outdoors

c. Keep doors closed

d. Hang garlic around your neck

7. Which of the following is false?

a. all spiders are arachnids

b. all arachnids are spiders

c. arachnids do not have antennae

d. Daddy-longlegs are not spiders

8. If you were a spider, how high could you jump, proportionately?

a. 85 feet

b. 130 feet

c. 260 feet

d. 350 feet

Arachnophobia

Because we've had more calls on spiders than usual this week, we are getting a jump on Hallowe'en by featuring information on spider control today. For all of you who have a touch of arachnophobia, the fear of spiders, be warned! Spiders are not always the bad guys. Fear of spiders may have sprung from myths and legends, or perhaps because of the few spiders that can be harmful. We've noted in a previous post how to recognize and avoid the two spiders in our area which can deliver a poisonous bite - the brown recluse and the black widow. Here's a little more general information on spiders, members of the arachnid family.

Unlike insects, spiders have eight legs and two body parts, a fused head and thorax. There are literally thousands of different kinds of spiders. While spider bites may itch, the vast majority of spiders do not have fangs big enough to puncture human skin. And they will rarely bite unless they feel threatened or trapped. The smallest spiders are around 1 mm in length, the largest can have a leg span of 10 inches! One of the distinctive features of most spiders is their ability to spin webs. Just as there are a huge variety of spiders on the planet, there are also a huge variety of web shapes and sizes. The black widow spins a heavy, irregular, messy-looking web - and prefer to spin their webs in dry, protected locations. For this reason, we advise home owners to remove wood piles, rock piles and other clutter from their yards - and do so carefully, with  gloves on. Indoors, spiders, webs and egg casings can be removed with a vacuum - the bag should then be sealed and disposed of.

But what about the spiders in your yard who go about the daily task of catching and consuming flies, mosquitos, roaches and aphids? Do we really want to get rid of them? For many, even though spiders are helpful in the yard, they prefer to dissuade them from a proximity to the house. After you have cleared wood piles, weeds and debris, if spider webs are noticed in the eaves of the house they can easily be knocked down with a broom. Check window and door screens to assure they are in good repair, as well as weather stripping at the base of all outside doors. Keep in mind that most spiders are helpful in the garden and non-threatening. They have even been helpful to scientific studies such as the one shown here, where spiders are observed after they have been injected with various drugs. The resulting webs  give us an idea of how chemicals can impair function. To learn more about spiders and how to control them, see the UC Davis web site here (pun definitely intended!). If all else fails, and those spiders are really bugging you, call  your pest professional.

Mystery Bug Week!

Often our blog posts ideas come from things that are going on here at Centurion. Right now there is a bug sample on my desk containing a "mystery bug." One of our customers sent a few bugs in a pill box to the office for identification, and here it is! Blog fodder! This week we will highlight a few of the most common uncommon bugs that show up for identification, hopefully answering a few of your questions and giving you tools to identify mystery bugs yourself. 

First, a few tips on getting a good Bug ID. Sometimes we can identify a bug just by asking you a few simple questions over the phone. The classic example is a call we occasionally get for cricket control. Usually the homeowner is being driven crazy by the constant chirping of crickets in the house. Our first question, which may seem insulting, is "Have you actually seen any crickets?" If not - check the battery on your smoke detector. Really. In this case, we have found the mystery bug is no bug at all, but a certain model of smoke detector that sounds remarkably like a cricket when the battery is low. Case solved!

If you have actually seen bugs and would like us to identify them for you, here are some tips on helping us do that. Try to get a good sample, two to three bugs that are not smashed. Dead is fine, smashed is harder. Put the bugs in a sealable plastic bag or other small, SEALED container. And please attach your name and phone number somewhere on the container. This really helps us get the information you need back to the right bug owner. 

We have magnifying tools and bug books to help us tell you what exactly is bugging  you and how to get rid of it. Occasionally we run into a bug we cannot ID here. The County of San Diego's Department of Agriculture offers a service to identify those rare bugs.

Brown Recluse Spider Black Widow Spider

One more tip: there are thousands of varieties of spiders. Identifying your  mystery spider may not be possible. There are two spiders to be concerned with here in San Diego County, the black widow and the brown recluse. We have included pictures of both and links to more information above. Although all spiders are venomous, most do not deliver enough venom to do any harm. Even the notorious black widow's bite will seldom do damage. However, if you experience abdominal pain, muscle cramps, or anything other than localized pain, check with your doctor. For identification purposes, black widow spiders weave webs that are thick and irregular. The spiders themselves are shiny black with thick legs. Females have a distinctive red hourglass shape on the abdomen. But who wants to turn one over to check? The best way to avoid attracting these spiders to your yard is to reduce or remove trash or rubbish from your yard. They are often found in wood piles, old tires or empty containers. Always check items that have been stored in a garage or shed before using - and wear gloves. But check the gloves before you put your hands in them! To see a video on black widows, click here.

Brown recluse spiders can deliver a more serious bite, but are very rare in San Diego County. The spider itself is brown, with a distinctive, dark brown violin-shaped marking near the head. The bite of the brown recluse can cause skin ulceration, and should be checked by a medical professional. There is no mystery about these spiders, but we include them here so you will know how to avoid them and will NOT try to collect a sample for us. 

Tomorrow's  mystery bug: Psocids!