Misconception Monday: Brown Recluse are Everywhere!

As a spider scholar (of sorts), I tend to get a lot of questions from just about everyone regarding the more infamous spider species. One of these species, the brown recluse, is well-known for having venom that is somewhat poisonous to humans, and so it has become somewhat of a curiosity to most individuals in the United States. Typically, people want to know how deadly this species is, where this species likes to live (i.e. inside or outside), and how to ID an individual spider as a brown recluse. Although there’s quite a bit of misinformation regarding these questions, the question I want to answer today is “What is the geographic range of the brown recluse (Loxoceles reclusa)?”

The main reason this question interests me is that, throughout North America, there is an intense, widespread fear of the brown recluse. Yet, if you look at the actual geographic distribution of spiders in the Loxoceles genus (see the map below), it is clear that the brown recluse species really only lives in a small part of the United States.

Loxoceles map courtesy of: http://spiders.ucr.edu/myth.html
Loxoceles map courtesy of UCR Spider Myths

Still, ignorance of the geographic range of this spider has two ramifications: 1) many spiders being misidentified and killed due to fear that they may be Loxoceles, and 2) people paying substantial amounts of money to have exterminators get rid of harmless spiders (this could be due to active scamming by exterminators, but I would guess that, more often than not, exterminators may not know how to identify brown recluse any better than their customers).

So, please use this map as your first means of identifying whether or not a spider in your house/work/garden/etc. is a recluse or not. If you do live in an area with recluse, or are just curious about this fascinating genus, please read more about them at the sites listed below. There is quite a bit of false information about the brown recluse on the internet, so it’s best to stick to websites and articles that are clearly written by people that research these critters!

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7468.html

http://spiders.ucr.edu/brs.html

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1071166/

http://www.burkemuseum.org/spidermyth/myths/fiddleback.html

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Spider of the Week: Phidippus texanus (Week 1)

Everyone, meet Linda, my new Phidippus texanus! I have spent way too much time watching/taking pictures of her this week, so I thought that I might as well share with everyone else.

photo 2-1
Linda, bein’ adorable, a few minutes after I first picked her up.

Spiders that belong to the North American genus Phidippus are some of the most well known jumping spiders of the Salticid family, as they are usually rather large and charismatic, and often have bright green chelicerae.

Can see a hint of Linda's green chelicerae in this shot.
Can see a hint of Linda’s green chelicerae in this shot.

Like many animals, Phidippus texanus is sexually dimorphic, in that females are mostly brown with some white stripes on their backside (see below), while males are black with bright red-orange coloring on the dorsal side of their abdomen (see picture here). This extreme coloration is possibly due to years of sexual selection, where male coloring could be a signal of health, good genes, etc… (see more on sexual selection here).

Linda - dorsal view.
Linda – dorsal view.

Anyway, I’m off to go do some DNA extractions for the rest of the afternoon, more info to come on P. texanus in the coming weeks!