Wednesday, June 12, 2013

The Catholic Spider: Basilica Orbweaver

Our holly bush is chocked full of Basilica Orbweavers! Scientifically known as Mecynogea lemniscata, these spiders get their common name from the way the females build their webs: an orb pulled up into a dome, with an irregular-shaped web nearby where they wait for prey. Dangling threads help knock down prey into the trap. Egg sacs are easily recognized as hanging chains:


Because of the 3D structure of the webs, I initially didn't believe these were orbweavers. Yet they are. Apparently anatomy and behavior contributed to this spider being placed in Araneidae instead of in Linyphiidae (Sheetweb and Dwarf Spiders).

Web design:

Body views:
I got 4 eyes in this shot!

Female wrapping up prey:

References:
http://bugguide.net/node/view/2029
http://www.insectidentification.org/insect-description.asp?identification=Basilica-Orb-weaver
http://eol.org/pages/1195623/overview
http://www.jstor.org/discover/10.2307/3705366?uid=3739896&uid=2&uid=4&uid=3739256&sid=21102099910003 (secondary use of removed orb web)
http://www.floridanature.org/species.asp?species=Mecynogea_lemniscata
http://www.spiderzrule.com/basilica.htm

2 comments:

  1. A little old, but I assume you get notified when people comment so I just wanted to say thanks. I was having trouble identifying this species, which has kind of taken over the deck-stairs at a friend's house. Mostly because I'm petrified of spiders and only really get a good look at the web as a result. This photoset is one of, if not the most comprehensive collection I found.

    Petrified as I am, they fascinate me, and these webs are absolutely stunning. Glad they're harmless insect murderers, cause they're laying eggs like it's going out of style. I've found 8 webs so far and the smallest chain of egg sacs is 5 tall :D

    But I digress. Great work. Thanks again.

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    Replies
    1. Hi Andrew,

      Wow, yes this post is old, but I saw your comment nonetheless! I appreciate your feedback, thank you. And yes, you're right about the egg sacs. It's funny: courtship takes ages, actual mating lasts a couple seconds, and the rest of the time the females eat and make egg sacs!

      FYI, our holly bush is still home to this species. The spiders there now are likely the direct descendants of the ones in these photos.

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