Dec 26, 2013

Visit from a Wandering Spider

Cessation of the heavy rains and the start of the drying, summer winds in Boquete drives insects indoors at the time of year.  I've been visited by multiple spiders, large ants, and the occasional scorpion from time to time, despite screening all doors and windows. I initially reacted to these encounters by aggressively fumigating the yard. Experience has slowly taught me, however, that fumigating only ups the ante on snake, worm, and insect entrances, albeit it weak and dying ones. I prefer now to keep the grounds weeded and the grass very short.  This practice has served me well.   It's been more than a year since the last scorpion and I did battle.  

So, I guess it was about time to find this large spider in my living room. More precisely, my cats found it at 3 am and created such a ruckus chasing it that they woke me up.   Feeling sorry for the poor creature, I considered just letting it be.  But it was really large---about 6 inches in diameter.  That worried me.  So I removed the cats and got out the insect spray.  
The little glowing dot seen in the center of this photo is the camera flash reflection from one of it's eyes.  It's body was about two inches long, and the leg span another 4 inches or so.  I really hated to disturb it, as it seemed pretty mellow up there.  I briefly though of encouraging him/her outside with a broom.  But to be truthful, that idea scared me. So in the end I called upon my inner assassin to push the button on the spray can.  Then I ran into the bedroom, closed the door with the cats inside, and crawled into bed leaving the lights on.

The next morning I found the unfortunate carcass between the sofa cushions and became clinical.  Spent a long time on the computer trying to identify the creature so that, in the unlikely event I should run into another one, I'd know if I needed to kill it or not.  I narrowed the spider's genus to either Cupiennius or Phoneutria.  I was particularly impressed with an article from the University of California, Riverside's website which defended the unjust fate of  harmless Cupiennius spiders, which are often mistaken for Phoneutria spiders.  

Brazilian Wandering Spiders, whose bites are potentially lethal, belong to the genus Phoneutria. These are also known as banana spiders, armed spiders, or "armadeira" spiders (Portuguese). Although the UC Riverside article mentions that Phoneutria spiders are endemic to Brazil, in actuality there are species,---Phoneutria boliviensis and Phoneutria fera, which are prevalent in Costa Rica, Panama and other parts of Central America. And sources apart from the UC Riverside author indicate that some [but not all] species of Cupiennius spiders are also dangerously venomous.  Most of the research regarding these two genera is recent,---- 2005 or later.  

Even with the internet, information that would empower a totally clueless person such as myself to make a confident identification is sparse.  I decided to rely on the experts and snapped more photos of the deceased. These I emailed on for expert conclusion.  To my consternation, the consensus came back that my visitor was a Phoneutria spider. 

Phoneutria bites contain a potent neurotoxin that is significantly more potent than that of a black widow spider. These bites are intensely and incessantly painful due to their excitatory effects on the serotonin receptors of sensory nerves. Per wikipedia,  "At deadly concentrations, this neurotoxin causes loss of muscle control and breathing problems, resulting in paralysis and eventual asphyxiation."  In Brazil human deaths are intermittently reported, and there even is case documentation where two children were killed by the same spider.  Anti-venom exists for Phoneutria spider bites, and should to be employed if a human is bitten.  Hospital treatment is indicated for Phoneutria bites. 

It's quite concerning to me that my early morning visitor was a dangerous one. It's not the first time I've seen such a spider.  Granted, this one was larger than most, but I see smaller versions quite frequently. They are especially appreciated by my cats, because besides running fast, they sometimes hop and jump when threatened.  I've been quite cavalier about dealing with them when found inside, choosing to let them come and go at will, not realizing their potential danger to the cats as well as myself.  My attitude will change. I wanted to post this as a heads up to other expat residents of Panama, who like me, might not realize they are a concern.  A quick glance might lead one to regard them as Wolf Spiders, which are harmless.   Wolf spiders, however, have a differently shaped thorax and abdomen.  

I was informed that the distinquishing characteristics of my Phoneutria spider were the dorsal line down the thorax and spots on the abdomen. The arrangement of the eyes is also unique, however my photographs don't illustrate this clearly.  There are actually three rows of eyes, the first row having 2, the second row having 4, and the third row having another 2.