Poisonous Black Widow Spiders – facts, webs and identification

What do you do when you find a Black Widow Spider?  Although spiders are important for the ecosystem and very beneficial to a garden, widow spiders are considered the most venomous spiders in North America.

Latrodectus, western widow spider poisonous

large female black widow with the red hourglass marks

Black Widow spiders are the most common species that belong to the Latrodectus genus, in the Theridiidae family. 

The web of a widow spider, Latrodectus,  looks like it was haphazardly thrown together.  The photo below shows silk strands grouped together with bits of leaves and sticks in the web.

black widow spider web photo

web of the black widow spider is tossed together with strands of silk

Black widow spiders tend to make their webs close to the ground in undisturbed areas.  The female widow spider is quite the homebody and likes to stay in her web.

Latrodectus genus of spider, in the family Theridiidae

a young spider and female black widow spider

Juveniles and adult male Latrodectus are much smaller than the female spiders and are a light brown or grey color.  Usually the male widow spider has several red, orange marks on his belly along with yellow or white bands on the top of the abdomen.

—  SPIDER FACTS  —

Latrodectus is a genus of spider which has 32 species, with varying markings and colors. The more common name is WIDOW SPIDERS.

Widow spiders belong to the cobweb spider family. They spin unorganized, irregular, messy webs to catch insects.

The black widow spider is shy and rarely leaves the web.  She prefers to make her home in dark, protected areas. Being nocturnal, this spider does its hunting at night.

spider with red marks

female widow spiders are larger than the males

It is wise to be cautious of this poisonous spider! Widow spider bites are dangerous because of the neurotoxin that causes the condition latrodectism - which is seizures and pain in muscle groups. 

brown spider with markings

juvenile and male black widow spiders are brown and smaller than the female

The female Latrodectus spider has extra-large venom glands and her bite is particularly harmful to humans.

In humans and dogs the widow spider bite can produce muscle aches, nausea, and a paralysis of the diaphragm that can make breathing difficult.  Most people bitten do not suffer serious damage or death.  A black widow spider bite can be fatal to small children, the sick and elderly.

Is the black widow spider bite fatal to dogs?  This is a big concern for me as I have two beloved dogs running about the yard.  This harmful spider bite to a dog is basically the same as it is to us humans.

Young dogs, older and those dogs with weaker immune systems are at higher risk for complications from a black widow spider bite.   ****Anti-venom drugs are available but need to be administered by your veterinarian.

Fortunately,  widow spiders are non-aggressive and bite only in self-defense.

poisonous spiders

spiders with large abdomens

Symptoms of a poisonous widow spider bite -

Once the spider’s poison reaches the blood, the venom is moved by circulation, causing its toxins to be deposited in the ends of the nerves that are inserted into the muscle.

The widow spider’s venom acts at nerve endings to prevent relaxation of muscles, causing seizures  —  constant, and painful muscle contractions.

Cramping in the stomach is often the most severe symptom but leg and back muscles may be affected also.

What to do after being bit by a widow spider?  SEEK medical attention after a poisonous spider bite.  Poison Control Website  or American Association of Poison Control  -  1-800-222-1222

Pictured below is the size difference between a male and female widow, Latrodectus, spider.

female widow spider is larger

size of male, female widow spiders, Latrodectus

Most people will recognize widow spiders by the hourglass markings on the underside of their abdomens. The hourglass mark is NOT present in ALL Latrodectus species.

The young female spider is more of a brown color with yellowish, white stripes across the top abdomen that change into the red hourglass shape as she ages and darkens to her black spider color.

most poisonous spiders

juvenile female black widow spider with white and yellow marks

The male widow spider is much smaller in size with brown coloring, and lacks the red hourglass mark the female is recognized for.

black widow before she turns black

young widow spider with yellow-orange marks on abdomen

spider white yellow marks

Latrodectus, widow spider with yellow marks, red dots on large abdomen

One way to rid yourself of a black widow spider is spray the web!  Wear protective gloves and spray the web well.  Spiders consume their old webs before they spin a new one.  Be careful always!

Latrodectus genus of spider, in the family Theridiidae

hourglass marking is common for poisonous widow spiders

dangerous harmful widow spiders

poisonous spider with white and yellow marks

In arid parts of Arizona, Latrodectus spiders inhabit almost every crevice in the soil and nests can be found in cholla cacti and agave plants.

Black Widow Spiders like undisturbed areas.  Keeping your home clean and vacuumed can help prevent these dangerous spiders from taking up residence in your house.


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black spider with white and yellow spots / marks – poisonous spider identified

Identified a poisonous widow spider with white marks or spots on a large abdomen.  Pictured below is a venomous spider that belongs to the Latrodectus genus, in the Theridiidae family. 

identify black widow spider

black striped spider with white marks, spots

Latrodectus is a genus of spider which contains 32 species. The more common name is WIDOW SPIDERS.

Widow spiders belong to the cobweb spider family. They spin irregular, sticky webs to catch insects. Widow spiders possess a row of bristles on their hind legs that form a comb, which is easily seen in the photos. The comb is used for flinging silk over its prey.

The black widow poisonous spider is perhaps the most common of the genus. Widow spider bites are dangerous because of the neurotoxin which causes the condition latrodectism(pain, seizures in muscle groups) —  this is where the name for the spider genus came about,Latrodectus.

The female Latrodectus spiders have unusually large venom glands and its bite is particularly harmful to humans; however, Latrodectus bites rarely kill humans if proper medical treatment is provided.

widow spider

black spider with orange yellow hourglass

Symptoms of a poisonous widow spider bite:

Once the spider’s poison reaches the blood, the venom is moved by circulation, causing its toxins to be deposited in the ends of the nerves that are inserted into the muscle.

The spider’s venom acts at nerve endings to prevent relaxation of muscles, causing seizures —constant, and painful muscle contractions. Cramping in the stomach is frequently the most severe but leg and back muscles may be affected also.

What to do after being bit by a widow spider?  SEEK medical attention after a poisonous spider bite.

spider with white spots

black striped spider with large abdomen

Most people will recognize widow spiders by the hourglass markings on the underside of their abdomens. The hourglass mark is NOT present in ALL Latrodectus species.

hourglass on spider belly

hourglass on black spider belly

In arid parts of ArizonaLatrodectus spiders inhabit almost every crevice in the soil and nests can be found in cholla cacti and agave plants.

The female’s spider venom is at least three times more potent than that of the males.  

Identify a spider with white spots, striped legs, yellow, white design abdomen stomach – Orb-weaver

This spider’s wheel shaped round web made identifying this striped legged spider easier.  Orb-weaver spiders are the most common garden spiders and love to hangout in the middle of their round webs.

spiders with striped long legs

spiders with white markings abdomen, Orb Weaver spiders

This colorful spider made a web marvel between two large Yucca plants.  It was a medium sized spider, a bit scary looking up close; but I was so intrigued with his large silky web!

orb weaver spider

striped legs spider with large abdomen markings is an orbweaver

Orbweaver spider

spider striped legs abdomen yellow design

The insect that wonders into the Orb-weaver’s sticky web will receive a quick stunning bite.  This spider has over 10,000 species and belongs to the family Araneidae. 

spiders with white marks on belly stomach

Common spiders with striped legs and white spots markings

spider 4-6 spots on abdomen

spider with white spots on abdomen

Within a few minutes an insect landed on the web and provided a meal for this Orbweaver spider.  All Orbweavers spin webs.  According to bugguide.net:  Female Orb-weavers spin the webs and are seen more often than the male spiders.

a baby orb weaver garden spider

white spider with black markings, a young orb weaver spider

It is late summer and I’m seeing spiders everywhere!  Fall is typically the time the female Orb weaver spider will lay her last clutch of eggs.   The spider eggs survive the winter and will hatch in the spring.

Orbweaver

gray spider white markings orbweaver

Another Orb-weaver spider was waiting on her round web for insects.  This spider was gray colored with striped legs and a white design on the abdomen.   The white design on the spider’s abdomen is clearer in the photo below.

abdomen with white design

brown gray spider with white markings

Orb-weaver spiders only bite if they feel threatened.  Their venom is not harmful to humans.   A bite of the Orbweaver spider feels like a bee sting.  They are active at night rebuilding and repairing their round shaped webs.

Are Orb-weaver spiders poisonous?    Spiders have venom.  Orb-weaver venom is potent but this spider venom is NOT dangerous to humans.    http://wiki.answers.com/Q/Is_an_orb_weaver_poisonous

eight eyes

eyes of an orbweaver spider

Orb-weavers and all members of the family Araneidae have eight similar eyes in 2 rows of four.  The spider’s eyes are pretty clear in the photo above.

large abdomen with markings

round spider web with yellow on a large abdomen – orbweaver spider

Orb-weaver spider

spider with white spots on abdomen

In the picture above, looks like two white spots on this spider’s large abdomen.  

Orb-weaver spiders can help control your mosquito population and are considered beneficial to have around!

orbweaver spider

spider yellow markings striped legs large belly

For identifying the spiders I posted today:

  • gray, brown colors
  • striped legs
  • spider with yellow markings on the abdomen
  • 2-5 white spots underneath the belly
  • spider with white markings on a gray abdomen

A large, hairy gray spider – Wolf Spider in my Lantana

Wolf spiders are expert hunters and pretty easy to identify due to their large size and hairy bodies.  If touched or threatened a Wolf spider will bite.   I was careful while observing this large gray, grey, Wolf spider that made his home in our Lantana plant.

Arizona hairy spider

grey hairy Arizona Wolf Spider

Wolf Spiders have over 2,000 species and are members of the Lycosidae family. They live mostly solitary lives and hunt alone. Some Wolf spiders will chase their prey and others will wait in their burrow for passing prey.  Wolf spiders are fast runners.

hairy spiders Arizona

Wolf Spiders, Lycosidae Family

Arizona Wolf spiders are generally hairy with varying colors from browns and grays.  Sometimes this spider will have a pattern along the back of the abdomen and head.  Wolf spiders have good camouflage for living in the desert.  They depend on camouflage for protection.

wolf spider

Gray Wolf Spider Eyes

The photo above and below shows the eyes of the Wolf spider.  They have eight eyes in three horizontal rows;  with 4 small eyes on the bottom, 2 large eyes in the middle and 2 medium eyes on the top.

eyes of hairy wolf spider

Arizona Wolf Spider, eyes

desert Wolf Spider

AZ Wolf spider row of eyes,  fangs – chelicera

The light from the flashlight has been reflected from the Wolf spider’s eyes producing a glow in the photo below.  According to the Arizona – Sonora Desert Museum, the eye shine is caused by a tapetum in the eye which reflects light rays back through the eye retina and probably enhances the spider’s night vision. Wolf spiders are primarily nocturnal predators and are rarely seen during the day.

wolf spider eyes glow

wolf spiders eyes glow with the flashlight

desert spiders long legs

large gray male wolf spider

The male Wolf spider has two additional leg-like appendages, called palps, that are attached behind the mouthparts.  These palps are used to hold and position prey and in the mating ritual.  Female Wolf spiders are larger than males.

palp of a male wolf spider

visible Palp of a Male Wolf Spider

Female Wolf spiders carry their egg case at the end of the abdomen by attaching it to their spinnerets.  The female spider holds her abdomen up in the air so the egg sac doesn’t drag on the ground.  When the spiderlings hatch they climb onto the female Wolf spider’s abdomen and hold her hairs.

Wolf spiders are capable of defensive bites if provoked.  Symptoms of the Wolf Spider’s venomous bite include swelling, pain, redness and itching.  The skin area at the Wolf spider bite may turn black. Swelling and pain can last up to ten days.

hairy light brown spider

wolf spiders in the desert southwest

Nevertheless, having wolf spiders is considered favorable because they consume undesirable arachnids.  I’m quite happy to have this Wolf spider guarding our large Lantana shrub.

 

What kind of spider makes a tunnel web – funnel web spiders in Arizona

This medium sized light brown spider with dark stripes built his tunnel web in our aloe and cactus plants.  Funnel web Spiders are known for their tunnel looking, funnel shaped webs.

webs that look like tunnels

Funnel Web Spider has a tunnel

These spiders are found all over the world.  There are over 600 species of funnel-web spiders, belonging to the Agelenidae family.

web with a hole in it like a tunnel

spider web looks like a tunnel

We have several species of aloe desert plants on our property which the funnel web spiders seem to keep occupied.  It is a fact that funnel-web spiders prefer moist environments.

brown grey spider in a tunnel web

funnel web gray brown spider

Funnel web spiders are shy and come out at night.  It was a cloudy day around the Tucson area and I was able to spot this arachnid repairing their web.

web with a hole entrance

spider tunnel web with an egg sac, funnel web

Funnel Web Spider

Funnel Web Spider carrying a large egg sac

The broad funnel shaped web, looks like a tunnel ( see photo below )  and is made by the spider to connect to their burrow.  When an insect enters the web the spider feels the vibrations and rushes out from the narrow end to bite its prey and inject it with venom.

fennel web

the web that looks like a tunnel

The Arizona funnel-web spiders are NOT the same as the deadly Australian Funnel-web spiders, Atrax robustus, and are NOT dangerous to humans.

  • The Australian Funnel-web spider is in the family Hexathelidae.
  • The Arizona Funnel-web spider is in the family Agelenidae.

If you were bitten by SEVERAL funnel web spiders the venom could make you very ill and you should see a doctor.

fennelweb spider

funnel web spider

Identifying a funnel-web spider:  These spiders have distinctive grey and brown stripes and patterns.

webs that look like tunnels

funnel web spiders make tunnel webs

Funnel web spiders have long legs with little bristles and small eyes in 2 rows of four.

Funnel web spiders have been mistaken Wolf spiders.  When identifying a wolf spider remember wolf spiders DO NOT spin webs.

spider with long legs

Wolf Spiders do not make webs

skinny spider with long legs

Wolf Spiders have smaller abdomens

I am not crazy about spiders but they are very important to the ecosystem and health of our planet.

SPIDER identified in my garden – black, gray, large abdomen, 4-6 white spots on belly

I’m on a quest to identify a spider near our pond as it is eating the damselflies **.  In the middle of a well engineered round web was a black, brownish, gray spider with striped legs.

**Damselflies are beneficial to the health of the pond.

spiders with striped legs and spots

Orb weaver spider eating

The wheel shaped web made identifying this family of spiders easy.

Orb Weaver spiders, common

spiders with spots and large abdomen

Orb-weaver spiders are the most common garden spiders and love to hangout in the middle of their round webs.

 

poisonous spider with large abdomen

Orb weaver spider with white spots, striped legs

QUICK FACT:  Spiders are venomous.    Spiders use venom to subdue their prey.  Fortunately, very few spiders are harmful to humans or even capable of penetrating the skin of a human.

white marks on spider

common Orb Weaver spider with 4 white spots

garden spider with striped legs

spiders with 4 marks on a large abdomen

 

Orb Weaver common spider

yellow design on the Orb Weaver spider

most common spiders, orb weaver

brown spider with yellow markings

This colorful spider made a round web marvel between two large Yucca plants.  It was a medium sized spider, a bit scary looking up close; but I was so intrigued with her large silky web!

spider with its prey in the web

common garden spiders are Orb Weavers

The insect that wonders into the Orb-weaver’s sticky web will receive a quick stunning bite.  This spider has over 10,000 species and belongs to the family Araneidae. 

spider with stiped legs

the 4 spots on a common Orb Weaver spider

spider with large abdomen and round web

an Orb Weaver spider caught a bee in her web

All Orb-weaver spiders spin webs!

spider with big yellow belly

the round spider web of the Orb Weaver

Fall is typically the time the female Orb-weaver spiders will lay their last clutch of eggs.  The spider eggs survive the winter and will hatch in the spring.

white markings on belly of spider

grey Orb Weaver spider carrying a damselfly

Orb Weaver Spiders belong to the family Araneidae and possess eight similar eyes, arranged in two rows of four eyes each.

spiders with round whell shaped webs

garden spider with yellow markings on its abdomen

With over 10,000 species for the Orb Weaver spider you are sure to see many varying patterns and colors.

common garden spider

Orb Weaver spider’s  large abdomen

Araneidae family of spiders

Orb Weaver spiders have designs on their backs

Orb-weaver spiders only bite if they feel threatened.  Their venom is not harmful to humans.

What does a spider bite feel like?  The bite from an Orb-weaver spider feels like a bee sting.

At night is a good time to see these spiders working hard to rebuild and repair their round, wheel-shaped webs.

identify spider with striped legs

identify a spider with white marks

For people searching to identify a spider that looks like the one I found in the above picture.  This is a spider with a large abdomen, gray and black striped legs, 4-6 white marks underneath the abdomen.

orb weaver garden spiders

spiders with 4 to 6 white marks on the bottom of the abdomen

Like all spiders, the young Orb-weaver looks like a tiny adult when it hatches.  As the spider grows it sheds it’s skin.  Spiders hatch in the spring.

juvenile orb weaver spiders

young orb weaver spiders with white legs

For identifying the spiders I posted today:

  • gray, brown colors
  • striped legs
  • spider with yellow markings on the abdomen
  • 2-6 white spots underneath the belly
  • spider with white markings on a gray abdomen

Orb-weaver spiders are good because they help control mosquito, fly and ant populations;  therefore, beneficial to humans.

TIDBITS:  How long does a spider live?  Most spiders live for only one year.