Stop This Meme

Here at Bug Eric, I have better things to do with my time than constantly fight wave after wave of misinformation, superstition, and outright hoaxes. The latest is this one purporting that a "new" and "deadly" spider has invaded North America. Utter nonsense!

The spider depicted in the images is the very much harmless Woodlouse Hunter, Dysdera crocata. This spider is originally from the Mediterranean region of Europe, but made its way to North America ages ago, not recently. Yes, it has wicked-looking jaws and fangs, which are used solely to turn over its roly-poly and sowbug prey so that it can inflict a lethal bite on its food, not on human beings. The venom of this spider has not been scientifically proven to be the least bit dangerous to the average, healthy person.

"But, but...." you say, citing the watermark on one of the images in the meme as being from the University of Nebraska. Surely we can trust our institutes of higher learning, right? Yes, but not if their image has been stolen by some malicious individual out for hits on his or her own website. The university should consider filing suit against whoever is using this image. There are laws against copyright infringement, which is what is happening here. The Digital Millennium Copyright Act (DMCA) exists to protect our "works" from unscrupulous individuals who seek to profit from our efforts at education and enlightenment.

By sharing this meme, and others like it, without doing due diligence of fact-checking (a quick check on Snopes would have yielded the truth about this one), serves only to perpetuate ignorance at best, and participate in crimes of "fake news" and, in this case, copyright violation. Stop it.

© Jenn Rose #jennrosefx

Woodlouse Hunter

This installment of “Spider Sunday” features yet another arachnid that causes undo consternation and fear among homeowners who encounter it inside their residences. The Woodlouse Hunter, Dysdera crocata, North America’s only representative of the family Dysderidae, is not dangerously venomous to the average, healthy human being or family pet.

That is not to say that this species doesn’t look formidable. It ranges from 9-15 millimeters in body length, and has very large chelicerae (jaws) with long fangs. The cephalothorax and legs are bright reddish brown or orange, and the abdomen beige or gray in color. These spiders have only six eyes instead of the usual eight that most spiders have, and they are arranged in a compact semi-circle at the front of the cephalothorax.

The Woodlouse Hunter is actually native to the western Europe, but has been introduced over much of the globe through commerce and other forms of human travel and enterprise. Here in North America it is most common in urban areas, favoring disturbed habitats in both forest and field.

Dysdera crocata is nocturnal, hiding by day under stones, logs, and boards or other debris. It ventures out at night in search of prey. The preferred prey is apparently terrestrial isopods known as woodlice, also called “sowbugs.” Sowbugs are also native to Europe, but now abundant in the U.S. and Canada. The spider uses its enlarged jaws and long fangs to pierce their armored prey, or turn it over and stab it in its soft underbelly. Captive Woodlouse Hunters will readily take other small animals as prey, so they are more plastic in their feeding habits than their name suggests.

Sowbug

The life cycle, revealed by captive rearing, is lengthy. It takes about eighteen months for an individual spider to reach maturity after hatching from the egg. A given specimen can then live an additional two to three years. Mating probably take place in the spring. Females contain a batch of up to seventy (70) ova within a rudimentary egg sac consisting of only a few strands of silk.

Look for the Woodlouse Hunter under objects outdoors. They may be hiding inside an oval, silken retreat, which they spin for purposes of molting and overwintering. Sometimes, the spiders stray indoors, and that is where they are most conspicuous. While there have been documented bites by this species, the symptoms amount to only localized pain lasting an hour or so, due mostly to the mechanical injury caused by those long fangs.

Dysdera is easily confused with Broad-faced Sac Spiders I the genus Trachelas, which have a nearly identical color pattern. Note that Trachelas has eight eyes, arranged in two rows across the wide front of the cephalothorax. Trachelas also lacks the long jaws and fangs of the Woodlouse Hunter.

Trachelas

I am keeping the specimen of Dysdera imaged here as a potential display animal I can take to public educational events. The more that can be done to alleviate our collective fear and loathing of spiders the better, and the Woodlouse Hunter can be a great ambassador for that mission.

Sources: Bradley, Richard A. 2013. Common Spiders of North America. Berkeley: University of California Press. 271 pp.
Jacobs, Steve. 2013. “Spider: the Woodlouse Hunter,” Fact Sheet. Penn State University Entomology Department.
Ubick, D., P. Paquin, P.E. Cushing, and V. Roth (eds). 2005. Spiders of North America: an identification manual. American Arachnological Society. 377 pp.