Araneus trifolium, the shamrock spider, is a widely distributed orb weaver that can come in various colors, mostly beige or brown colors. It can usually be identified by its three dark rings around every leg.
Shamrock Spider Description
The abdomen of the Shamrock Spider can come in several colors. I have seen pictures of them that were red, orange, pale yellow, white, brown and even greenish.
The quickest way to recognize the Shamrock Spider from other Garden Orb Weavers, is the white bands on the legs. Not all the Shamrock Spiders have these white bands, but when you do see the white bands, it is likely an Araneus trifolium.
The body of the Araneus trifolium grows to be about 3/4” (19 mm). Including the legs, the Shamrock Spider can grow to almost 1 ½” (38 mm) across.
As other orb weavers as well, the shamrock spider uses a web to catch small flying insects. Some webs of shamrock spiders have been seen with a diameter of over 2 feet (60 cm). They rebuild their circular web every single evening to catch insects at night.
The bite of the Shamrock spider can be somewhat painful and may cause some minor irritations or swellings. The symptoms may be similar to a bee sting.
Araneus trifolium scientific classification
- Kingdom: Animalia
- Phylum: Arthropoda
- Subphylum: Chelicerata
- Class: Arachnida
- Order: Araneae
- Infraorder: Araneomorphae
- Family: Aranidae
- Genus: Araneus
- Species: Araneus trifolium
Distribution of the shamrock spider in the USA
The shamrock spider can be found in every US state and in Canada: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming
23 thoughts on “Araneus Trifolium – Shamrock Spider”
Hi, I live in south central Alaska. Found this yellow spider with striped legs today. We have a lot of orb weavers with striped legs- maybe it’s another type in that family? Slightly hairy.
Hello Angela, thanks for getting in touch! You are right, this is some type of orb weaver – a male specimen. Given your location and the spider’s color, I would say that this might be a shamrock orb weaver (Araneus trifolium): https://usaspiders.com/araneus-trifolium-shamrock-spider/
About the third time we’ve spotted this guy in the garden (various spots). We are on cape cod. He’s great to have around- eats all the nasties that annoy us!
Hello Heather, thanks for sharing this great shot! Your shamrock spider appears to be pregnant and will probably create and egg sac soon.
Found Sept. 6, 2021 on a fence post in a field in Kent, WA. I am guessing some sort of orb weaver, but it doesn’t match any pictures of the common local varieties.
Hello Karen, thanks for getting in touch and for sharing this great shot! This is a shamrock orbweaver (Araneus trifolium). They can come in a variety of colors: https://usaspiders.com/araneus-trifolium-shamrock-spider/
This spider was very large and pretty with the the white and black colors. It was hard to get a great photo. It’s seen here eating an insect.
On concrete driveway @ Saint Moritz Strasse in Park City, Utah.
Hello Charlie, thanks for getting in touch! This is definitely an orbweaver. It’s most likely a shamrock spider (Araneus trifolium): https://usaspiders.com/araneus-trifolium-shamrock-spider/
Found in South East Wisconsin.
I have the same spider in Statham, Georgia. I noticed the first one on 9-28-2021. I have another that I noticed today 9-30-21. What kind of spider? It looks very hairy.
Hello Debra, the spider in your backyard is a spotted orbweaver (Neoscona crucifera): https://usaspiders.com/neoscona-crucifera-spotted-orb-weaver/
Hello Dorothy, thanks for getting in touch! This is definitely a harmless orbweaver. To me, it looks like a somewhat dehydrated male shamrock spider (Araneus trifolium): https://usaspiders.com/araneus-trifolium-shamrock-spider/
This spider has been living in my window for over a month. I keep the window closed but opened the screen so it wouldn’t starve. Has an unusual shaped abdomen, and is large enough to kill a hornet that flew in between the screen and window. I’ve enjoyed watching it build webs and hunt. This is in ND.
This guy was sauntering down the sidewalk, about half a block from Lake Michigan in southwest Michigan. Spider was about the size of a silver dollar. Body was sand colored, with pale gray and black striped legs, and white spots on body.
Hello Laura, this is a shamrock orbweaver (Araneus trifolium): https://usaspiders.com/araneus-trifolium-shamrock-spider/
Is this lovely lady a Shamrock Orb Weaver?
Black and white legs. Spots on his back. About the size of a quarter. Found him inside my screen door.
Hi Kaitlin, this is a shamrock orbweaver (Araneus trifolium): https://usaspiders.com/araneus-trifolium-shamrock-spider/
Found in garden Sep 11 2022, Homer, Alaska. Photo is in the bottom of a glass jar, so there is distracting distortion in the background.
Hi James, this is a shamrock orbweaver: https://usaspiders.com/araneus-trifolium-shamrock-spider/
I saw this spider on an overhang. I live in Washington state and have never seen one like this before. A friend told me that it may be a Shamrock Orb Spider?
I found this guy living under my mailbox on the south coast of Massachusetts.