Tuesday, November 7, 2017

Rotting Log Exploration


The WOLF students were exploring rotting logs at their Bull Mills field trip.  The most exciting find was several northern black widow spiders, Latrodectus variolus, with their typical disconnected hourglass on the ventral abdomen that we discussed in this September blog.  They also found a few smaller black spiders with orange and white markings.  I have submitted these to Bugguide and am awaiting a definitive reading but I suspect by their size and coloration that they are sub-adult males as seen at this link.
"The mature males are much smaller with abdominal markings that are more red-orange and either continuous or broken red-orange strip bordered by white down the dorsal midline of the abdomen. It also has several pairs of white stripes along the sides of the abdomen. Juvenile females can show a similar pattern of the mature males." Tarantulaspiders.com
False Wolf Spider, Zoropsis spinimana
There were lots of spiders crawling around in the wood and not all had eight legs after encountering the students' tweezers.  The spider above which I am calling a false wolf spider, Zoropsis spinimana, was as patient as a fashion model, letting me get views from all angles.  The image on the left was the exuvia of a spider, the skin it shed after molting.
Polygyridae snail, immature
Snails are common in rotting logs where their rasp-like mouths can scrape up fungal mycelia.  Chris Barnhart identified this as a pulmonate (air-breathing) snail in the Polygyridae family.  It is immature and measured only 10mm and spent the afternoon crawling laps in the Gerber babyfood bug box.


A final bonus was Mrs. Reece's find of this Halloween special, a marbled orb weaver.  These normally have a firm round abdomen but this one had just concluded her egg laying and was crawling through the grass displaying her new slim and dimpled physique.

More of their finds are at this link.

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