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 ↩
28 Comments. Leave new
I have what I think is an Orb Weaver but, not sure which kind it is, how do I email a photograph so you can help me identify my spider or a link I may use.
You may either click the “Ask WTB?” link on our homepage or use this link to submit a photograph. You should be aware that this is our busiest time of year and our small staff is unable to respond to every request.
I was bitten by this same shape spider but it was black with a white top. Hurt like heck! a day later my leg muscles are so sore like I ran 5 miles. Is this bad?
This is not considered to be a dangerous spider, and the reaction you had sounds usual for a spider bite.
In Carrboro, NC….This spider actually jumped BACK on me from the pavement after I brushed it out of my hair as if attacking. Aggressive. Not sure if this is normal behavior or not.
This spider doesn’t jump back, you probably pulled it like sling shot from the web still stuck to your hair
I have seen that this spider is in the southern half of the states but I have a whole bunch at my house in Rhode Island
I killed a spider with a white triangle on its butt. When I smashed it, I looked to see if it died. Well when I opened up the toilet paper I seen it was dead but in its butt there was a little thin gray coil of a worm. An it was hard to kill, I had to masked it like 4-5 times before it finally died. Do you know what that worm like thing would have been? I’m freaked out. Thanks.
Sounds like a parasite.
oh no have you seen the movie alien
We live in the country above Durham, NC. I went out last night to close up our chicken coops and feed the rabbit when I almost walked into a giant web! I shined my light up to see this spider with a white triangle on its back waiting on the edge of a tree branch. Then not even two feet away was another one with a yellow to green triangle working on its own web. Strangely though there was no sight of them today. One instinct is to agree with my wife and burn down every tree and bush in our yard that doesn’t produce fruit. Evey night like the last brings me one step closer to doing just that. Even though I’m the one trying to convince her some spiders are good for the yard and environment; that sudden awareness you just got web all over your face and head and don’t know where the spider went or what kind it was, is extremely frightening for the most courageous. Needless to say, I am the only one with the faith and stupid willingness to cautiously brave the risk of a face full of web around here. Thank you for identifying my nocturnal nemesis stalker in waiting.
Spiders get into the house, too. You’ve probably even run into a web there at some point. So, you might need to also burn the house down….. 🙂
I’m in the Union Ridge area of northern Alamance County. I almost ran into one of those creepy little spiders while cleaning up after my dog late in the evening. The one I saw was red with the white triangle.
Late August through Sept and Oct is the worst time for tree web spiders. The really big ones that come out in the fall really creep me out.
I have been out after dark with the dogs and my flashlight, shining the light around the edge of our treeline checking for critters so the dogs don’t go running. I have caught little bright glowing object in the trees or tall grass. With curosity kicking in I had to go check it out only to find out it was the eye of a big creepy spider watching me from its perch on the tree branch.
I’m in the Union Ridge area of northern Alamance County. I almost ran into one of those creepy little spiders while cleaning up after my dog late in the evening. The one I saw was red with the white triangle.
Late August through Sept and Oct is the worst time for tree web spiders. The really big ones that come out in the fall really creep me out.
I have been out after dark with the dogs and my flashlight, shining the light around the edge of our treeline checking for critters so the dogs don’t go running. I have caught little bright glowing object in the trees or tall grass. With curosity kicking in I had to go check it out only to find out it was the eye of a big creepy spider watching me from its perch on the tree branch.
Right now is prime spider-hunting season, with webs becoming more obvious as the spiders reach maturity, and leaves start to fall during autumn. Enjoy looking for them. Google Book Search provides previews of several pages of text and plates so that you can judge for yourself the quality of the book.
This spider was found on my porch in Ohio this morning.
I found this spider on my deck when I was covering the grill this morning. I saw it on my shoulder. I felt a string of web so I pulled it away hoping the spider was still attached and it was. It was not aggressive but it could be dying or sick because it didn’t seem very active or interested in a quick get away. It landed on the deck floor. I bent down to see what kind it was and I had never seen this spider before. It had a shiny white triangle back. I took a picture and it looks just like the one above. It’s their world too so just researching to better understand this little guy- is it safe or something I should avoid coming in contact with.
I’m located in Alabama. I didn’t mention that in my previous post.
I also found this spider hanging from my table edge. It has a white triangle on it’s back.I live in Waleska ,Ga.
Just found an arrowhead spider this morning (Sept. 15, 2017) in Gnadenhutten, Ohio. He began with one strand between a tree and a hanging basket stand which are about 11 feet apart on either side of a sidewalk. The web was built off that, and it was probably 5′ in diameter with the little spider in the center. It was quite a foggy morning, and the dew on the web helped us see it before we walked into it. We broke out the cameras immediately & got a few good shots. Good thing, too. My husband told me that the little guy had dismantled the web by about 1 PM. I posted pics on instagram #brickhouseonmain
I found this same little guy in my yard this morning with him just hanging out in the middle of his huge web stretched across the grass and trees. The web was about 6′ diameter and the spider was a light brown with a large white triangle on it’s back. I live in the Washington, D.C. suburbs and the past couple weeks have been running into spiders I’d never seen before. Just the other day I ran into a gray spider with a white cross on its back on my deck also. He has a web on my deck and I have been throwing moths in his web the past few nights watching him feed on those. Its fun to watch that little cross spider run to those moths and wrap them up in a cocoon and carry them to the rest of the cocoons at the top of his web. I don’t think he will ever go away if I keep feeding him every night. I think I will name him cross contamination… C.C. for short! Lol!
I saw this little beauty in Bristol, TN, last night. 47 years of spider fascination and I’ve never come across one in NC, VA, or TN. “Mine” was solid black, though, which made the perfectly equidistant, white triangle appear even more stark. Quite striking design, evolution! Thanks for helping identify!
Yes the one on my shoulder was black too, (while just sitting on the bed!) making the white brighter. Gaffney, SC
Haven’t seen anyone say they’ve seen one in SC! Im going to keep researchin to make sure they are ok and not poisonous lol.
Yes the one on my shoulder was black too, (while just sitting on the bed!) making the white brighter. Gaffney, SC
Haven’t seen anyone say they’ve seen one in SC! Im going to keep researchin to make sure they are ok and not poisonous lol.
I found one on my kitchen floor. I took a picture then killed it because I thought it might be poisonous and I have kids. We are in central TN. It was black with a white triangle on it’s back.
Hopefully, learning that they are harmless (actually beneficial) creatures will help to preserve the life of the next one you encounter.
We saw one beauty: full black with white triangle in the Land Between the Lakes (Kentucky/Tennessee). Almost to walked right through its web… but luckely saw it just in time so my husband could put it safely to the side. Happy to read it was not poisonous.
Hello, was googling this Arrowhead spider, and found this site. I face planted into the web and it was in my hair, I was in the woods, so I got it out, and took pictures of this neat lil guy. And put him back on a tree. Would post a pic bit d ont know where. I live in South central Arkansas
Found one in Northwest Louisiana, in my house. I just left it alone, and here it remains. Hopefully, it will catch and murder these deadly mosquitos that plague us here.