Sunday, November 18, 2012

Spider Sunday: Hentz's Orbweaver

Some spiders simply cannot be ignored, and judging by the volume of images and questions we get over at Spiders.us, the most conspicuous spider of late summer and fall is one of the spotted orbweavers: Neoscona crucifera. Indeed, the spiders and their webs are very conspicuous.

This species was formerly named Neoscona hentzii, hence the common name. It is also known as the “Barn Spider,” but it unfortunately shares that name with another orbweaver, Araneus cavaticus. The two look similar in size, shape, and color. Neither species has a distinct pattern, but the markings on the underside are often more consistent, and a slightly better way to distinguish the two in the field.

Mature females of N. crucifera measure 9-20 millimeters in body length, while males range from 5-15 millimeters.

This is a widespread spider, found from Massachusetts to Minnesota, Nebraska, Colorado, and southern California, south to Florida and central Mexico. It favors moist woodland habitats, but can turn up in yards, gardens, parks, and even under the eaves of homes and other buildings. Outdoor lighting attracts insects at night, and many kinds of orb weavers seem to know this. So, they may stretch their webs across your front porch, garage door, or other convenient spot where they can intercept moths, flies, katydids, and other potential prey.

Immature N. crucifera build their webs only at night, taking them down at daybreak. By removing their webs they erase any obvious clue to their presence that birds or other predators may notice. The Black and Yellow Mud Dauber, Sceliphron caementarium, and the Organ-pipe Mud Dauber, Trypoxylon politum, are especially adept at finding orb weavers by following the framework of a web. Remember, the foundation lines of spider webs are not sticky, so can be navigated with impunity by both the spider and its predators alike. The cost of losing potential daytime prey captures pales compared to the benefit of remaining undetected by your own predators.

Adult females leave their webs up during the day, the owner hiding at the periphery of the snare in a curled leaf, or huddled on a twig.


She usually sits head-down in the center, or “hub,” at night. As insects become scarce in autumn, she needs to maximize her prey-catching opportunities, both day and night. The spider consumes a damaged web, recycling the silk.

Mature male orb weavers strike out in search of females and may be found wandering almost anywhere. Not only do adult males not bother spinning webs once they are sexually mature, but they actually lose the physical capacity to do so. They no longer manufacture the types of silk necessary to spin a web. All energy goes into finding a mate. The males mature faster than the females, so some may patiently wait in the vicinity of a female’s web until she becomes an adult.


male

Once mated, females prepare an egg sac, laying up to 1,000 eggs in a spherical or convex mass, covering it with a layer of fluffy, yellow silk, and usually concealing it in a rolled leaf. The sac measures only 5-12 millimeters in diameter.

Orb weavers in general are great to have around your home as they kill many insect pests. Their webs are glorious accomplishments of animal architecture; and the spiders themselves are harmless to people and pets, despite their sometimes intimidating size. Enjoy their beauty and presence before the killing frosts come.

Sources: Barnes, Jeffrey K. 2003. “Hentz’s Orbweaver,” University of Arkansas, Arthropod Museum Notes No. 23
Lapp, Joe. 2007. “The Intelligent Neoscona crucifera,” SpiderJoe.com.

42 comments:

  1. This is great! Thankyou! and the 1,000 spiderlings on my patio really thank you!

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  2. Good info. I likely will continue to have difficulty distinguishing between spotted orb weavers and barn spiders, but I don't suppose it's critical. I'll just enjoy them!

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    1. Exactly! Thank you for sharing your appreciation. :-)

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  3. Um they bite. There everywhere in side and outside. We have fruit trees ,cherry trees and these critters can spin a web darn quickly.

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  4. I have a beautiful specimen right outside of my back door. She spins her web every night from my awning down too the back porch hand rail. She is quite aggressive with her prey and it is mesmerizing watching her as i do almost every night. Once she even took a moth i offered her right out from my finger tips.

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  5. Thank you, you're more informative than Wikipedia 😀 thank you for helping me identify the spider I saw out by our rabbit hutch, I got a good picture I wish I could share.

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  6. https://imgur.com/a/e0XHuNX
    This specimen built a web next to my front porch light,and she seems to do really well for herself. Thank you so much for the great information! Thanks to you she can stay there as long as she likes.

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  7. So my friend found one that is pink with black and white legs. The video of it is amazing. What kind of orbweaver would it be?

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    1. Without seeing the spider, I can't be certain, but my bet would be one of the many color variations of the Marbled Orbweaver, Araneus marmoreus.

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  8. Ours is feasting on yellow jackets daily. Especially in the am here in So. Cal!

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  9. I have one on my balcony. The web is gorgeous. I’m a bit of an arachnophobic, but I’m learning to enjoy watching them without fearing them.

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    1. Thank you for sharing your mental metamorphosis! :-)

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  10. I have one just outside the back door. She hides up in the windowsill in the day. She doesn't always spin a web. Why? When she does, often it's really sloppy and thin like a cobweb. Why is she so lazy? I look at that web and tell her, you are going to starve if you don't put more effort into that web. Often she spins a web after midnight. She has no set routine. If I see a bug, I'll find the best part of her web to toss it. Why does her freshly spun web have so many gaps?

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    1. Love this fun web page and seeing the comment history. We have an orb weaver resident for a couple of weeks that has the exact weak and small web that Vicki described in her 10/16/2019 post. Spidey went without building a web for days until it rained and then she built a small web. I wonder if she was starving and did not have the raw material to build a web until she got water in her. I added a bug to her new web and she pounced on the bug and began eating immediately! After the feast, her abdomen went from gray and pointed to orange and plump by the next day. Unfortunately, she is not in a good location and never catches anything. I fed her again in hopes she would get some strength to pack up and leave for a better location since our orb weaver inhabitants will move on if they find themselves in a bug free zone (and I'm sure the unnatural act of feeding her will only encourage her to stay). I do wonder why she stays with such slim pickings.

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  11. How long do they live & can I do anything to encourage them to stay around?

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    1. Lifespan seems to vary considerably, but usually only one generation per year. If you have insects for them to feed on then they are automatically "encouraged" to stay around. :-)

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  12. Do they bite & if so, is it dangerous? This morning I was pulling weeds in my lily beds and one got in my hair. She crawled out after I went into the house & really startled me! I was able to gently capture to identify before putting her back outside. I don't she bit me.

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    1. Nearly all spiders have a venomous bite to subdue their prey. Very few bite in self-defense, and hardly any are dangerously venomous to the average, healthy human or pet. Unless you have a compromised or hypersensitive immune system, you should have minor pain, briefly, at worst.

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  13. Is there any way to save them from the frost? I have one in my carport and I love watching her. I'd hate for her to die this winter.

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    1. Your empathy is appreciated, but please do not intervene in the natural course of things. You would be doing the spider no favors by bringing her inside, for example.

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  14. There's huge amounts of them all around my yard the web is starting to get very annoying is there anyway I can kind of control this?? Also how long will they stay around ?all the way until winter??

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    1. Not sure how they are "annoying." They persist until the first hard frost, usually. Meanwhile, they are controlling insects that would be a far worse nuisance if they proliferated unchecked.

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  15. I came across this spider the other night and you are correct about the size being intimidating. Spun its web on my back porch by the light of course. When I went to show my boyfriend the next day and it was gone then back again tonight. Google to the rescue with your image of the exact spider. Even the position of the legs and all almost identical. Thank you for making it so easy to identify!

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    1. Thank you for sharing your experience, and for the compliment!

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  16. Mine is not the exact same spider, from what I saw she is a Hentz Orb-weaver? She has beautiful stripes on her hind and makes a massive web EVERY morning as the wind nocks it down. I wish I could post photos she will have to be relocated soon as we are putting up Christmas lights and we don’t want her there during the process. Will she, or would she already have had babies? Before winter? Texas winter isn’t super harsh till much later. It’s actually still very warm out.

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    1. I can't really speak to your particular circumstances of weather and climate. Generally, orbweavers in temperate climates have already made egg sacs, but that may not be the case for subtropical regions.

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  17. Found a big web strung up beside our back porch light, my mom was going to knock it down but I told her not to. A few hours later after the sun went down I heard her shout. She was doing laundry and the resident spider had come to sit in her web for the night. I didn't recognize it but went to look up what kind as she was concerned about how venomous it was. The reddish upper legs and dark stripes were rather striking and I'm fairly certain the spider is one of these gals! Thank you for the good pics and info! They've convinced my mom to leave the spider be since she's not in the walkway.

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    1. Thank you for sharing this delightful story!

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  18. We have one of these beauties living right outside our dining window. She gives an amazing demonstration of how to take out the moths trying to get in! Third night watching her build her web again. Just wonderful!

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  19. I also have one of these beauties outside my dining room window. I examine her web every morning and shortly thereafter she retreats to the top corner of the window to rest. This morning she was snacking on an impressively sized grasshopper (maybe?) and it was so fascinating to watch! Thank you Eric for the picture and education on this!

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  20. We live in a heavily wooded area in western NC. I guess we’re pretty fortunate to have about a dozen of these around our house this year, and those are just the ones I know of! They’re doing a number on the stink bugs.
    We did have to rescue a little 6 inch ringneck snake today who was caught in one of the strands and just hanging midair. I guess that shows how strong the cobweb is. It can tangle up a snake and hang it off the ground. Glad we spotted it!
    Thanks for the post and letting us all share. Please post a photo of an egg sac if possible.

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  21. Hello BugEric! I love your blog.
    I'm currently attempting to identify an Orb Weaver, I'm in the North Cascades National Park. I'm not familiar yet with the spiders of this region because I only arrived here yesterday. I try to educate myself on the local spiders wherever I go (I live nomadically) but this one is new to me. She had red striped legs and a green back with a unique pattern. I know they can vary so much so it is difficult to tell, I could not get to the back side of the web to see her belly without flubbing up the web. I'm a huge fan of spiders, huge! Jumpers are my favorite, but Orv Weavers are next in line on my list!
    Is there a way I could send you a photo of this Orb Weaver and you could help me to identify her?

    Happy Spider watching!!

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    1. Thank you for the kind compliments! You are welcome to e-mail an image or two: bugeric247ATgmailDOTcom. Make sure you note in the subject line that you approached me on the blog.

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  22. “My” N. crucifera caught a monarch butterfly right in front of me last night, then only ate the body and dropped the wings on the ground. I felt bad for the monarch, especially considering the state of the species, but I love my spider friend (even if her size does intimidate me a bit)!

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    1. Thank you for sharing your experience, Hannah!

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  23. Great info Eric! thanks for sharing

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  24. We have one that has been living on the ledge right beside our porch light for at least a month. She is efficient and I appreciate all of her hard work keeping the pests that come to our back porch light at a minimum. When the family turns off the porch light I turn it back on so she is sure to get a nice steady supply of nourishment. We have smaller ones on each of our smaller porches and one near the clothesline. Approximately 1/2 dozen or so in all around the house. We live in a heavily wooded area of WNC and they are abundant. They are quite an enjoying thing to watch. Earlier in the late summer months around August we had a very large Hentz on the back porch and she created a rather large web. I sat an just watched her for an hour or more. It was like watching an artist at work. Thanks for the great info. I wasn’t sure it was Hentz at first but after coming her and large lady on the back porch near the light, who has built her web in the form of upside net type configuration, was kind enough to let me see her back and belly I am certain. I didn’t touch or disturb her, she is just docile and used it us coming and going underneath her that she didn’t mind me looking I am sure. The markings are 100% match. Thanks for the info Eric!

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  25. Thank you for this info! We have one who lives on our front porch. We named her “mama spider” (without really knowing if she actually a female). I’m pretty sure she knows we won’t harm her. We’ve made it a habit to talk to her every evening when she comes down to her web, never getting too close, of course. We simply tell her hi & thank her for keeping the mosquitoes at bay!

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  26. I have one inside my house should i be worried? It also looks like a female because its on the bigger range of size.

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  27. Saw a gorgeous one on a small tree near a bright light on the lakefront path in Chicago today. Weaving her web after sunset, then sitting in the hub. Web started to fill w small insects. The black and white mark on the belly plus the size and shape of the web helped ID her . So cool !

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  28. this is so cool!! i live in virginia, and a little less than three hours before sun down, i saw a goliath web being built at incredible speeds by this exact spider. thank you for sharing; the information and photos were very helpful for identifying this beautiful creature. it chose a great spot, between two porch lights, and i know it will be eating very well from now on :D!

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