Megawebs at Arkansas Bend Park (Fall 2016)

Here are some pictures from this year’s megaweb at Arkansas Bend State Park in Lago Vista, Texas. Similar to last year’s web at Lake Ray Hubbard, these webs are primarily constructed through the efforts of thousands of Tetragnatha guatemalensis (common name: Long-jawed Orbweaver). Of course, there are many other species present within the webs! And also, pictures and videos just can’t do it justice, if you can make it out to the park, I highly recommend visiting the webs in person 🙂 Enjoy! Videos to come.

Pictures from a megaweb in Northern Texas (August 2015)

In Texas, it seems that heavy spring rains bring lots (I mean LOTS) of late-summer spiders. For instance, in 2007 a giant spider web popped up at Lake Tawakoni, made from the labor of thousands of Tetragnatha guatemalensis individuals (with possible help from some other species). The running hypothesis for these massive spider outbreaks can be simplified to this: heavy rains cause huge blooms in insect populations, spiders feed on these insect populations, and so, spider populations grow to larger-than-normal sizes. Although orbweavers such as T. guatemalensis do not normally cooperate in web-building (that is, they are not social spiders, per se), they may be more tolerant of others and even share web space when prey populations are large enough (i.e. competition is low). Joe Lapp (or, Spider Joe) carefully documented this outbreak, and you can read more about it (and watch some interesting videos of spider behavior), here on his blog.

I wasn’t living in Texas in 2007, and so have only heard about these occasional massive outbreaks of spiders. Although this is the stuff of most peoples’ nightmares, it is the stuff of an arachnologists’ dreams. So, when I heard that this August (2015), there was another outbreak in Northern Texas, I was very excited to be able to see it, and take a few pictures to share with others. Unfortunately a few days before I could go to the site at Lake Ray Hubbard, officials had sprayed pesticides around the area, in an effort to control mosquito populations. Thus, the webs that I saw were not as pretty and pristine as those shown on the news (see links below), and many of the spiders had died as a result of pesticide exposure. Still I got a few good images and it was really a wonder to see the sheer number of spiders that could all live in one place.

 

You can read more about the 2015 outbreak (and find some pre-spraying pictures of the webs) by following the links below:

http://abcnews.go.com/US/thousands-spiders-spin-mega-web-spans-hundreds-feet/story?id=33011151

http://dfwreport.com/spider-webs-rowlett/

 

Sometimes I take pictures of spiders with my iPhone….

Hi all,

Guess what…. I’m buying a real camera soon! This means that I’ll finally be able to be a real ento-blogger, educating the world about all the cool critters out there 🙂

In the meantime, here are a few pictures I’ve taken over the past year of spiders (and other arachnids) using my current camera (my iPhone). Enjoy!

Misconception Monday – Comic: A Spider Did Not Bite You

This comic, A Spider Did Not Bite You from Buzz Hoot Roar, is just plain fabulous.

https://i0.wp.com/buzzhootroar.com/wp-content/uploads/BeatriceSpidersLARGE-01_biggest.jpg

All credit goes to: Roar and Katie McKissick. AKA Beatrice the Biologist, McKissick is a blog and science comic that hopes to make science fun and interesting for the casual reader. Visit www.beatricebiologist.com to see more of her work, and follower her on Facebook and Twitter.

Article: The Case for Spider Conservation

A new exhibit at the AMNH seems to be reviving the public’s interest in spiders, and with that, the question of “why should we care about spiders?” is inevitable. So, the Washington Post released this nice article summarizing a lot of ways in which humans will benefit from spider conservation and research. Enjoy, and remember to be friendly to your fellow spiders 🙂

Spider of the Week: the Twin-flagged Jumping Spider (Anasaitis canosa)

This week’s spider is inspired by a beauty that I found in my shower (!) a couple weeks back. Not entirely sure why she was trying to set up camp in there, unless perhaps she was thirsty. Anyway, here are a few glamour shots, plus a couple cool facts about this species. Enjoy the holiday weekend!

Anasaitis canosa from Austin, TX. This species gets its common name from the two large silvery-white spots on the top of its pedipalps.

Anasaitis is a small, currently paraphyletic genus (part of a clade with Corythalia. See: Zhang & Maddison 2013) . Most species are found in the Caribbean, but A. canosa occurs throughout the Southeastern United States.

These spiders are tiny! (Hand and knee of a ~5’8″ woman (myself) for scale).

This species often feeds on ants, as individuals live in leaf litter of forest floors. One observational study of A. canosa‘s hunting behavior found that this species will follow its prey along complex routes, and are perhaps even capable of internalizing and triangulating prey location. See the following paper for more info. It’s a very fun read! Hill 2006 Predatory pursuit of ants.

Like many other spiders, females produce egg sacs that they guard until the eggs hatch. Here’s a picture of my new friend with her newly produced sack. Hopefully I’ll get to see a few little jumper spiderlings sometime soon!

A. canosa female with her egg sac (top right).
A. canosa female with her egg sac (top right).

Last but not least, here’s a great video that makes the “twin flags” and  beautiful iridescence of A. canosa much more apparent.

 

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 can be harmful 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

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!

Back from a long hiatus… with lots of spider news!

Sorry for the long wait, but hopefully you all are ready to learn more about spiders! While I haven’t been posting about spiders, I have been learning a TON about them, and have lots of fun things to talk about, now that I know so much more about arachnids.

To start, here are just a few of my favorite spider-related studies that have been published during the last seven months… enjoy!

Spider silk may be ready for commercial production

Hormiga & Griswold published this great review of the evolution and systematics of orb-weavers – PDF: AnnuRevEntoOrbweaving2014

Velvet spider genome + draft of Tarantula genome published in Nature!  PDF: SpiderGenomesNature2014

Jonathan Pruitt’s social spider research gained a bit of coverage  in the NYT. PDF: SocialNicheConstructionProcB2014

As did this cart-wheeling spider. 🙂

I’ll be discussing some of these studies further in the near future, as well as talking about an arachnology course I took in Costa Rica, and my own research, so keep checking back for new posts!