The Arrow Shaped Micrathena Spider is a fascinating little creature that is native to various regions in North America.
Known for its distinct arrow-shaped body, this intriguing orb weaver spider is quite easy to identify.
As a type of spiny orb weaver, the Arrow Shaped Micrathena spins intricate, circular webs in which it rests and catches prey.
Arrow Shaped Micrathena Spider Basics
Scientific Classification
The Arrow Shaped Micrathena Spider, scientifically known as Micrathena sagittata, belongs to the following classification:
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Arachnida
- Order: Araneae
- Family: Araneidae
- Genus: Micrathena
Physical Description
Arrow Shaped Micrathena Spiders are orb-weavers known for their distinct appearance.
The females showcase striking reddish, black, and yellow colors with a yellow abdomen.
They also have three pairs of tubercles tipped with black and red. The large pair of tubercles at the back resembles an arrow shape, giving the spider its name.
Males, on the other hand, are small and rarely seen, with less vibrant coloration compared to females.
Distribution and Habitat
Arrow Shaped Micrathena Spiders are found in various habitats, including forests, parks, and wooded areas.
They are most commonly spotted in the Eastern United States, from Florida to New England, and as far west as Texas.
They create intricate, circular webs and are often seen resting in the center of their webs.
Appearance and Characteristics
Abdomen Structure
The Arrow Shaped Micrathena Spider, an orbweaver, is known for its unique and distinct abdomen structure.
Its triangular or “arrow-shaped” abdomen is mostly observed in females, while males are smaller and rarely seen.
Pointy Tubercles
- Three pairs of tubercles
- Tipped with black and red at the base
- The pair of tubercles at the back end forms two corners of the triangular shape
The abdomen has pointy tubercles that add to its peculiar appearance.
There are three pairs of tubercles with the pair at the back end of the abdomen being rather large, forming two corners of the triangular shape.
These tubercles are tipped with black and red at the base, contributing to the spider’s striking appearance.
Source: Judy Gallagher, CC BY 2.0, via Wikimedia Commons
Color Variation
- Reddish, black, and yellow colors
- Top surface of the abdomen is yellow
- Colors mostly observed in females
The Arrow Shaped Micrathena Spider exhibits a beautiful color variation, with reddish, black, and yellow colors.
The top surface of the abdomen is predominantly yellow, with the other colors appearing as accents.
These color features are predominantly seen in females, while males, being smaller, are not as noticeable.
Life Cycle and Behavior
Spiderlings
Arrow Shaped Micrathena spiders start as eggs laid by the female spider.
After hatching, these tiny spiderlings go through several stages called instars before becoming adults.
Diet and Feeding Habits
These orb-weaving spiders catch their prey, typically insects, using their intricate, circular webs.
They are not venomous to humans, but their venom effectively paralyzes their prey.
Lifespan
Quick Fact: The lifespan of an Arrow Shaped Micrathena spider is about one year.
They progress from eggs to spiderlings and ultimately adults within this time frame.
Mating and Reproduction
The male Arrow Shaped Micrathena, which are smaller and less colorful than females, approach females for mating.
After mating, the female lays eggs and encases them in protective silk capsules.
Comparison Table: Arrow Shaped Micrathena vs. Triangle Orbweaver
| Arrow Shaped Micrathena | Triangle Orbweaver |
|---|---|
| Yellow abdomen with black and red tubercles | Carapace and legs can be black, brown, or rusty red |
| Webs are usually low to the ground | Webs are often higher off the ground |
| Primary habitat is deciduous forests | Can be found in various habitats, including woods and meadows |
Web Construction
Orbweavers’ Circular Webs
The Arrow Shaped Micrathena Spider is an orbweaver, meaning it constructs intricate circular webs.
These webs are primarily built by females, who are often observed resting in them.
Sticky Strands
These spiders use sticky strands to capture prey.
The webs are a marvel of engineering, providing a strong and efficient means of capturing insects for sustenance.
Defensive Features
Some features of Micrathena webs serve defensive purposes as well. For instance:
- Coloration: The striking reddish, black, and yellow colors of the Arrow Shaped Micrathena can deter predators.
- Tubercles: Females have 3 pairs of tubercles on their abdomen, tipped with black and red, adding to their unique appearance.
| Feature | Arrow Shaped Micrathena | Typical Orbweaver |
|---|---|---|
| Web shape | Circular | Circular |
| Web construction | Sticky strands | Sticky strands |
| Main builders | Females | Females |
| Defensive features | Coloration & tubercles | Coloration |
Regional Distribution
Eastern United States
The Arrow Shaped Micrathena is common in the Eastern United States, where it spins intricate, circular webs. It is mostly found in woodland areas 1.
Central America
In Central America, the Arrow Shaped Micrathena is also found but in lesser numbers compared to the Eastern United States.
Missouri
In Missouri, the Arrow Shaped Micrathena is observed resting in its webs commonly. Females have striking reddish, black, and yellow colors.
They sport 3 pairs of tubercles, tipped with black and red at the base 2.
Mexico
As for Mexico, information about the Arrow Shaped Micrathena distribution is limited.
However, it is expected to be found in areas with similar ecosystems to those where it thrives in the Eastern United States and Central America.
Species Variations
White and Black Micrathena
The White and Black Micrathena is a type of orb-weaver spider.
It has a unique combination of white and black coloring on its body. Some key features of this spider include:
- Black legs
- Striking black and white pattern on the abdomen
This species is known for spinning intricate, circular webs where they commonly rest 1.
Source: Judy Gallagher, CC BY 2.0, via Wikimedia Commons
Spined Micrathena
Another variation is the Spined Micrathena. This spider has pointy, conical tubercles on its body, giving it a “spiny” appearance. Distinctive traits include:
- Glossy black legs
- Combination of black, red, and yellow colors on the abdomen
The Spined Micrathena spins circular webs, like other orb-weavers 2.
White Micrathena
The White Micrathena is another orb-weaver species that exhibits a predominantly white coloration. Key characteristics are:
- White abdomen
- Brightly colored tubercles, possibly red or yellow
This spider also creates circular webs where it rests 3.
Comparison Table
| Species | Color | Web | Tubercles |
|---|---|---|---|
| White & Black | White and black | Circular | No |
| Spined Micrathena | Black, red, and yellow | Circular | Pointy, conical |
| White Micrathena | Predominantly white | Circular | Colored (red or yellow) |
Is The Arrow Shaped Micrathena Spider Dangerous?
No, the Arrow-shaped Micrathena spider (Micrathena sagittata) is not considered dangerous to humans.
While it has a distinctive appearance with its arrowhead-shaped abdomen and spiky projection, its bite is not known to cause significant harm to humans.
Like many orb-weaver spiders, its primary prey is small insects that become caught in its web.
As with any spider, it’s a good practice to avoid handling them to prevent accidental bites or reactions, but overall, the Arrow-shaped Micrathena is not a spider of concern in terms of human safety.
What Does The Arrow Shaped Micrathena Eat?
The Arrow-shaped Micrathena spider primarily feeds on small insects that become ensnared in its web.
These could include various flying insects like flies, mosquitoes, gnats, and other small arthropods.
The spider constructs an intricate and symmetrical orb-shaped web to capture its prey.
When an insect gets trapped in the web, the spider quickly immobilizes it with its silk threads and then proceeds to consume it.
The web’s design and positioning help the spider maximize its chances of catching prey that flies or crawls into its vicinity.
Further Reading and Resources
Books and Publications
For those interested in learning more about spiders, including the Arrowshaped Micrathena, we recommend the following books:
- How to Know the Spiders by B. J. Kaston: A classic guidebook by a leading expert in the field, providing detailed information about various spider species.
- Land Invertebrates by WCB/McGraw-Hill: This comprehensive textbook covers a wide range of invertebrates, such as earthworms, slugs, snails, arthropods, crayfish, shrimp, millipedes, centipedes, and mites.
These publications will provide a solid understanding of spider biology, behavior, and classification.
Research Studies
In addition to books, several research studies focusing on the Arrowshaped Micrathena and other Spiny Orbweavers have been published:
-
Levi’s study on land invertebrates: This research focuses on the various animal species of invertebrates, including the Arrowshaped Micrathena. It offers insights into their unique characteristics and behavior.
-
Studies on sticky strands and stabilimentum: These studies look at the intricate web building techniques of Spiny Orbweavers, such as the Arrowshaped Micrathena, and how their sticky strands and stabilimentum are effective in capturing prey.
| Web Characteristics | Arrowshaped Micrathena | Other Spiny Orbweavers |
|---|---|---|
| Sticky Strands | Yes | Yes |
| Sharp Spines | Yes | Some |
| Stabilimentum | Present | Varies |
These research studies provide valuable knowledge about the unique features of Arrowshaped Micrathena spiders, giving spider enthusiasts a deeper understanding of this fascinating species.
Conclusion
In conclusion, the Arrow Shaped Micrathena Spider, with its captivating arrowhead-shaped abdomen and intricate circular webs, stands as a remarkable species within the world of arachnids.
Native to various regions of North America, this orb-weaving spider showcases distinctive colors and tubercles that contribute to its unique appearance.
While not considered dangerous to humans, its venom aids in subduing its prey, primarily small insects that become ensnared in its finely woven web.
As it rests at the center of its meticulously crafted trap, the Arrow Shaped Micrathena continues to weave its intriguing story in the vast tapestry of the natural world.
Footnotes
- Search Result – White and Black Micrathena
2 - Search Result – Spined Micrathena 2
- Search Result – White Micrathena
Reader Emails
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.
Letter 1 – Arrow-Head Spider, Verrucosa arenata
Hello,
Your site is the most comprehensive collection Ive seen so far. I live in North Carolina. Something has been biting me (but not my wife?) at night. The bites are not painful but can be really itchty at times. I found this spider crawling in our sheets this evening.
Given its very distinctive white triangle on the back and striped legs I thought the ID would be cake. After looking at many sites, including yours, I have yet to find a match.
We have seen many different kinds of spiders in and around our house so this one may be unrelated to the bites. Still Id just like to know what we’ve got here.
Thanks
Paul
Hi Paul,
We love getting good photos of new species for our site. My old Comstock Spider Book calls your spider Verrucosa arenata and you have a female. Some authors call the genus Aranea.
The abdomen is distinctive and triangular in outline. The large triangular spot can be white, yellow, pink or green. It is a Southern species that is occasionally found as far north as Long Island. It is probably not the cause of your wife’s bites. A Google search turned up a site that had this information:
“The arrow-head spider, Verrucosa arenata, has three distinct color forms, which occur in the same habitat. Our goal is to understand the ecological and behavioral factors that allow for the maintenance of this polymorphism.
More specifically, we are interested in understanding how predation (e.g., crypsis) and assortative mating maintains these color forms.”
Letter 2 – Arrow-Shaped Micrathena
Here is an unusual spider that we found on our bushes in front of our house in Nashville, Tennessee. I tried to search for it to identify it online but to no avail and I came upon your site. Can you identify it? Thanks!
Rhonda
Hi Rhonda,
This is an Arrow-Shaped Micrathena, Micrathena sagittata, one of the orb weaving spiders.
Letter 3 – Arrow-Shaped Micrathena
If you find out what this is, could you please let us know. I’m most interested to learn if it is poisonious or not.
Thanks much!
Alicia
Hi Alicia,
This is an Arrow-Shaped Micrathena female, Micrathena sagittata. It is found at woodland edges, shrubby meadows and gardens in the East, ranging as far west as Texas. They are harmless orb weavers. Do you know the famous pediatrician Winston Lutz of Winchester?
Letter 4 – Arrow Shaped Micrathena
Hi!
Just came across your site, and it’s fantastic! Can you confirm whether this little darling is a Micrathena sagittata? Most of the sagittata photos I have seen show this species with much more yellow than black. This photo was taken at Cumberland Island, GA, in August.
Thanks,
Karen
Hi there Karen,
You certainly do have the Arrow Shaped Micrathena here. This is a shot of the underside, hence the markings look different. Additionally, there is often much variation from specimen to specimen.
Letter 5 – Arrow Shaped Micrathena
Hello,
I was walking past my apple tree this evening and saw what I thought was a spider crawling up a web from the ground. But when I got closer I wasn’t so sure. It does have eight legs but the yellow body is hard like a crustacean. What is it? Is it poisonous?
Thanks. Janet
THE LOY’S
Hi Janet,
This is an Arrow Shaped Micrathena, one of the smaller orb weavers. Your specimen is a female. All spiders have venom, but most, like this gal, are not harmful to people.
Letter 6 – Arrow-Shaped Micrathena
I saw it last summer on my lilac bush after the blooms has past. I live in Medway MA.
Carin Cohen
Hi Carin,
Your diminutive spider is an Arrow-Shaped Micrathena.
Letter 7 – Arrow-Shaped Micrathena
Subject: Help! Is this dangerous?
Location: Williamsburg
January 7, 2014 7:57 pm
We live in the very far south of Kentucky in a place called Williamsburg. We found this crawling in our car this fall.
Since we live surrounded by woods we thought we had seen almost every bug out there, but this is a new one…and no one has been able to identify it for us yet!
Signature: Whitney and Paul Johnson
Hi Whitney and Paul,
You encountered a Spider known as an Arrow-Shaped Micrathena, Micrathena sagittata, and according to BugGuide: “This spider does not pose a danger to humans (and neither do any others in this family).”
Its family is Araneidae, the Orbweavers, and the members of this family build a classic circular web that they rarely leave. It is believed that the spiny body of this spider makes it difficult to swallow by small predators including birds.
Letter 8 – Arrow-Shaped Micrathena
Geographic location of the bug: Francestown, NH
Date: 08/15/2019
Time: 11:35 AM EDT
Your letter to the bugman: Saw this spider on a dead oak leaf today, very interesting body with spikes!
Googled around a bit and could not find it.
Would love to know what it is.
How you want your letter signed: Alfred Eisenberg
Dear Alfred,
This intriguing spider is an Arrow-Shaped Micrathena, Micrathena sagittata, and according to BugGuide: “This spider does not pose a danger to humans (and neither do any others in this family).”
Thanks for that! I did actually find that eventually but nice to have it confirmed. Beautiful spider I have not seen before.
Letter 9 – Arrowhead Spider
Hey there bug people!
I ran across this spider on my deck this morning here in Frederick County, Maryland. From my google searches I can confidently say it’s a Verrucosa arenata of the yellow variety.
I saw you have a white one on your site and I thought maybe she could use a friend. Cheers,
James Pryor
Hi James,
Thanks for sending us your lovely photo of an Arrowhead Spider. We believe, once upon a time, we also received an image of a pink Verrucosa arenata.
Letter 10 – Arrowhead Spider
March 22, 2010
I found this bug on the side of my car a few years ago around September. It was about the size of a dime, maybe a little bigger but not by much. I live in a rural area in eastern Virginia and have seen many bugs but never one like this.
No one else I talked to could identify it either. I was so excited when I discovered your website and am hoping that you’ll be able to solve this mystery. Thanks for your help!
Grace
eastern Virginia
Hi Grace,
We haven’t posted a photo of an Arrowhead Spider, Verrucosa arenata, in years. You may see additional images on BugGuide. The Arrowhead Spider is one of the Orbweavers, and it is not dangerous.
Letter 11 – Arrowhead Spider
Location: Woods/ around house, Junior, West Virginia
August 3, 2016 6:11 pm
This was hanging form my AC outside my window. As long as it won’t kill me it can stay. Let me please
Signature: Jennifer
Dear Jennifer,
The Arrowhead Spider, Verrucosa arenata, is a harmless species. You may verify that on BugGuide where it states: “Like other orb weavers, it is not dangerous to humans.” Can you please provide a state or city for the location?
Letter 12 – Arrowshaped Micrathena
Tue, Oct 14, 2008 at 12:10 AM
At the end of a camping trip in Rock Island, TN, we were taking down our tents when I found this little critter.
Originally, he was on the tent, but I moved him onto a nearby tree with a leaf so he wouldn’t get squished amongst our packing. I’ve never seen this species before and I was just curious as to what type of spider he/she is.
I also wanted to mention I love your site. Through it, I’ve figured out what baby wheel bugs, house centipedes, and female dobsonflies are!
Much thanks,
Sarah Bowers
between middle and east TN
Hi Sarah,
This little beauty is a female Arrowshaped Micrathena, Micrathena sagittata. It is a harmless orbweaver that is found in wooded areas.
Letter 13 – Arrowshaped Micrathena
September 8, 2009
I was sitting on my backyard swing and my 18 mos old brought my attention to this spider, she thought it was a bee. I put it in a bug jar and took a couple pictures of it. It is between 1/4-1/4 inches long.
We live in SW Pennsylvania And it’s nearly fall here. I’m just wondering what kind of spider it is, I’ve never seen anything like it around here before !
I am petrified of spiders, so I can’t believe I actually got this in a jar.. haha Any information you have would be very much appreciated. Thank you.
Momma of Three
South Western PA
Dear Momma of Three,
Suddenly we have gotten quite behind in our responses. The new semester with budget cuts has brought added responsibility to our already busy lives. This is an Arrowshaped Micrathena, Micrathena sagittata, a harmless Orbweaver. You can read about the species on BugGuide.
Letter 14 – Arrowshaped Micrathena
October 13, 2009
About 2cm long, less than 1cm at the widest part
KC
Salem Ohio
Hi KC,
This is a spider known as the Arrowshaped Micrathena, Micrathena sagittata.
Letter 15 – Arrowshaped Micrathena
Location: Scotrun, PA USA
January 23, 2012 10:26 am
found this bug on the outside of our door on 9/24/11. Temp was around 77 and sunny. the yellow body was about 1/2” overall.
Signature: Jean
Hi Jean,
This pretty little spider is a harmless Arrowshaped Micrathena, Micrathena sagittata. According to BugGuide, it spins its small webs in open woods.
thank you ever so much for identifying this spider, it really is very pretty.
Letter 16 – Arrowshaped Micrathena and Goldenrod
Location: Troy, VA
September 18, 2016 12:22 pm
Hi Daniel,
I’m trying hard not to inudate you with photos, but I thought you might like this image of an arrow spider by some goldenrod. While the spider is not using the goldenrod as direct source of food, it is nicely camouflaged by the goldenrod and seems to be using it as a way to hunt insects that do feed on the goldenrod. The yellow of the spider and the yellow of the goldenrod are remarkably similar. Also, it’s such a cool little spider.
Signature: Grace Pedalino
Dear Grace,
One couldn’t help but to disagree more with your belief that this Arrowshaped Micrathena “is not using the goldenrod as a direct source of food” because though it is not eating the goldenrod, it is eating the insects that are attracted to the goldenrod.
While Arrowhead Micrathenas would survive without the goldenrod, we believe that they and other orbweavers as well as carnivorous insects including preying mantids thrive in a goldenrod meadow.
This is a marvelous addition to our Goldenrod Meadow tag and we agree heartily that the coloration of the Arrowshaped Micrathena is perfect with the goldenrod. Here is a nice BugGuide image of an Arrowhead Micrathena.
We forgot that we had a 10 Most Beautiful Spiders tag, and we are adding your Arrowhead Micrathena to that tag.
The post Arrow Shaped Micrathena Spider: Your Quick Guide to Discovery appeared first on What's That Bug?.
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