Egg sac of an Argiope aurantia

This is an egg sac of an Argiope aurantia orbweaver. It's about 2 cm (3/4") in diameter. The array of threads surrounding the egg sac help to protect it from predators and parasites.


Comments

Post a Comment

Popular posts from this blog

Mystery of the Misumena fidelis Crab Spider

Image
Mexico and the United States are missing a crab spider. It's not the most inconspicuous of spiders, either, being one we should see on flowers. Read on to see how biological taxonomy is sometimes detective work about the names and shapes of things... Summary A fortuitous series of circumstances, along with some sleuthing, reveals that Misumena fidelis Banks 1898 is properly Mecaphesa fidelis (Banks). It is very likely synonymous with Misumenops volutus F.O. Pickard-Cambridge 1900. It may or may not also be synonymous with Misumena decora Banks 1898, which Gertsch 1939 might have mistakenly synonymized with  Misumenops volutus . An examination of the Misumena decora type specimens should resolve that. Mecaphesa fidelis ranges along the western half of Mexico, south to Guatemala, and possibly north into southern Arizona. Last Seen in 1901 Cotype of  Misumena fidelis  Banks 1898, from MCZ There are supposed to be two species of Misumena crab spider (family thomisidae
Read more

How Spiders Get Bigger by Molting

Image
It had always been a mystery to me how arthropods manage to get bigger by shedding—or "molting"—their exoskeletons. If you're molting an exoskeleton, you're losing mass, right? It makes more sense that an arthropod would get smaller by molting. I've seen spiders before and after molting, but it wasn't until I witnessed a large spider molting that I finally understood what was going on. It turns out that I had seen the process before when a butterfly emerges from a chrysalis. It is most apparent that a spider's legs get longer after molting. Here are two photos I took of a spider in 2011. Both photos are of the same spider, taken two days apart. The bottom photo is of the spider prior to molting, and the top is of the spider after molting. The measurements given are the lengths of the first legs. The two photos are proportioned correctly relative to each other, so you can visually compare the before and after sizes. The spider is a male Mecaphesa d
Read more

A Book Written by Spiders

In the woods there are webs. Some we know well, like the orb webs that spiral to the center. Some surprise us on the forest floor, gauzy sheetwebs that taper to a funnel. Some are messy constructs like the cobwebs in the nooks of the trees. But everywhere, everywhere, strands glint rainbows in the sunlight. Stretching from branch to branch, leaf to leaf, twig to twig, they are the trails of passing spiders. Here is a spider now. She raises her abdomen and releases a line into the air. She waits. The line catches. She pulls the line taut, anchors her end, and climbs across. Once across, she ambles on. Behind her the line reads, "A spider was here." So reads the line before, and the line before that. So reads every line in the forest. The forest is a book written by spiders. It reads, "We spiders are everywhere." (Written on the morning of October 18th, 2009, in the woods of Gus Fruh Park, Austin, Texas)
Read more