Re: What is the most posionous spider in the world?

This is certainly a debatable question, as arachnologists often disagree.  
At present most seem to be leaning toward the South American Phoneutria 
fera (Ctenidae), with the Australian Atrax robustus (Dipluridae) second.   
Spiders in the genus Sicarius (Sicariidae) are also in the running, but as 
few people ever come into contact with these odd spiders from the South 
American deserts they have not acquired the notoriety that the others have. 
The black widows and violin spiders are further back in the list, with 
other species of Atrax and Phoneutria probably ahead of them.  Keep in mind 
that the ranking is to some extent arbitrary, as we are comparing 
neurotoxic and necrotic venoms and also that a very potent venom may be 
delivered in small amounts, while a less potent venom may be delivered in 
massive quantities.