Things I Learned This Week

Heading to the SF Bay Area this weekend to catch up with family and friends! Here are your spider links for the week:

Another interesting story about Nefertiti, the Spidernaut.

If you’re in the Riverside, CA area (and courageous enough to try to catch a brown widow spider!), you can help with this study.

Fun video of a tarantula on the prowl.

Some spiders use electric charges to trap insects… amazing!

I can’t wait to see a web like this in person one day.

Why do spiders have so many eyes?

Don’t forget to check for ticks!

A new study on black-legged ticks in New York State has linked these arachnids with another, rare, but serious disease: encephalitis. Please make sure that, if you spend any time in the woods or tall grasses this summer, you always check yourself for ticks once you come inside. And check your pets as well! Animals tend to brush up against plants even more than we do, and can be infected by, or carriers of diseased ticks.

If you find a tick on yourself or someone/thing else, it is best to be very careful in removing it from the skin:

Tips for tick removal – CDC

Tips for tick removal – WebMD

Also, if possible, you should save the tick in a ziploc bag, in the freezer. If you or your pet end up feeling ill in the next few weeks, then the doctor could use the tick to help in diagnosis, if the symptoms alone are not enough.

Stay safe!

LiveScience – “The suprising cause of most ‘spider bites'”

Just ran across this great article that explains how many “bites” that people self-diagnose as spider bites, are unlikely to actually be caused by spiders. It may seem that I stress this misconception a lot on the site, but it is one of the main reasons why people are so scared of spiders, and so willing to harm them or to look at them in disgust, when really, they are such fascinating creatures! Spider bites do occur, and can be dangerous, but the reality is that they are quite rare compared to much *more* dangerous arthropods and diseases.

OK. Enough ranting from me… Enjoy your week, and if you find any cool spiders, feel free to send me some pictures or stories about them!

Things I Learned This Week

Hope all of my American friends had a lovely holiday yesterday (and for all you Non-Americans, I still hope that you had a nice Thursday!). Here are some awesome spider biology links to help get you through the long weekend. Cheers!

These siblings know how to share their belongings.

Oh good. Male spiders are sometimes cannibalistic as well…

Yet, female spiders still seem to be better off, in most cases.

Yeah, I really wouldn’t want to be a male spider

NASA is building a spider-like robot called the Spidernaut.

And, at one point there was a live “spidernaut” in the ISS.

 

 

 

 

 

Spider of the Week: The Basilica Orbweaver

A few months ago, my advisor went spider collecting for me, and came back with this really cool species:

Emma5.21.13lemniscata(b) (2)

This beautiful spider, Mecynogea lemniscata, gets its common name, the Basilica Orbweaver, from the domed-shaped, horizontal web that individuals build. While I don’t know everything about this species, here are a few interesting facts that I have learned so far:

  • Females attach egg sacs to each other vertically , and hang them from a thread. Some people even mistake these spider cocoons for butterfly or moth cocoons, as this egg sac structure is not incredibly common in spiders.
  • Females will detach their webs every night, so that they fall onto their egg sacs and provide another layer of protection for their eggs (spider behavior is SO incredible! See Carico, 1984 for more information)
  • Similar to P. oweni, individuals will occasionally aggregate on trees or bushes, in areas with high prey density and numerous web support structures. Some will even share support lines, though they keep their own, individual retreats.  It is likely that they do this to increase prey capture efficiency (See Buskirk, 1986 for more info)
  • The horizontal, dome shape of their webs has caused some controversy as to what family this spider really belongs to, as webs like this are usually characteristic of spiders in the Linyphiidae family. Many orbweavers build the classic, vertical, spiraling webs that most picture when trying to imagine a spider web. However, morphology and behavior tend to place these spiders into the Araneidae family, and most researchers believe, nowadays, that the M. lemniscata web structure is simply a classic example of convergent evolution with the Linyphiidae family web structure.

Carico 1984

Buskirk 1986

Misconception Monday – Do all spider bites leave two fang marks?

Many people think that the characteristic mark of a spider bite is two symmetrical marks in the middle of a bite. Sort of like this (Note: do not search for “spider bite” under Google Images if you are easily grossed out):

Spider bite or not?

Well, I’m here to set the record straight. Yes, spiders do have fangs at the tips of their chelicera that they use to bite and inject venom into their prey (See: How Stuff Works – Spider Venom). Therefore, it is possible that if a human received a spider bite, there would be these distinctive fang marks. However, the reality is that spiders rarely bite humans at all, and if one did bite, most spiders are likely too small to ever leave two fang marks that are clearly visible to the human eye. In addition, two side-by-side marks are not always indicative of a spider bite. Many arthropods can bite more than once, leaving marks that might look like two fang marks to us, but really are two separate bites. Because of this, spiders can certainly be wrongly-accused of biting humans much more than they actually do (on the other hand, if the spider is small enough, it could get away with it!)

The easiest way to tell if a bite is from a spider or not is to catch the perpetrator in the act. Unfortunately, once you notice a bite, it is usually too late. If you are really worried that you’ve been bitten by one of the few dangerous spiders out there, then there will be other symptoms to look for. The number of bites that you see may hint at whether it is a spider bite or not, but is not a form of diagnosis, alone.