Most dangerous spider in the world

Which spider is the most dangerous in the world?, and which is the most poisonous?
A wound from a spider may be dangerous in many, and sometimes unpredicted, ways.
First of all spiders has evolved their venom to target their main prey - insects. Since humans belongs to mammals the venom from spiders is generally less harmful to humans than insects. However, there's many examples of people getting killed by spiders, so the first thing to consider is the toxicity of the venom.
The second thing to consider is the size of the spider. In general, the larger the spider the more mechanical damage to the victims skin is imposed.
The third thing to consider when evaluating which spider is the most dangerous is the abundance of the spider compared to the density of humans in the area where it is living.
Also, factors like habitats and behavior should also be considered.
Taking all of this into account the brown recluse spider is probably the most dangerous spider in the world.

Widow Spiders

Widow spiders also constitutes a significant threat to people in the United States. The most well known is the Black Widow Spider, but if based on venom needed to kill a man the Brown Widow Spider is in fact more dangerous than the Black Widow.
However, because of its sheer size, the Black Widow is more dangerous than the Brown Widow. Its venom is perhaps 50 percent as dangerous as the venom from a Brown Widow, but its ability to penetrate human flesh is much better than that of the Brown Widow.

Most poisonous spider in the world

Which spider is the most poisonous of the world ?

The most venomous spider in the world is the Brazilian wandering spider also known under its Latin name Phoneutria nigriventer. At the bottom of this page you'll find a picture of this spider.
The venom from the Brazilian wandering spider is so toxic that 0.006 mg of it can kill a mouse.
If you are not living in Brazil or the countries close to Brazil there might be some other spider more dangerous to you than the world most venomous spider.

Most poisonous in the United States

The most poisnous spider in the United States is probably the Brown Recluse Spider. Other well known American spiders are the widow spiders. Of these, the brown widow is slightly more venomous (has the most potent venom) of the two. However, because the Black Widow Spider is larger it is capable of inflicting more dangerous poisonous bites. The Hobo Spider, which cannot be found in the most popolous states of the US such as Florida, Texas, New York and Washington is also rather poisonous, although some reports about this spider is widely exaggerated, to put it mildly.

Australia

Australia is home to some of the most poisonous spiders in the world such as the funnel-web spider and the red-back spider. The red-back spider is actually a widow spider also known as Latrodectus Hasselti. This black widow spider is also very small, so one has to be very careful. The funnel-web spider has a characteristic web formed like a funnel. Its latin name is Atrax robustus. This funnel-web spider has many close relative in the United States, that are not nearly as poisonous as their Australian brethren.
In the articles section you might find more information about the most poisonous spider of your area if you live in the United States.