What are you talking about 2 of every "kind"?
A species is a kind.
You're saying that God saved 2 black widow spiders and you have tarantulas today?
Are you implying now that evolution exists?
A species and a biblical "kind" are not the same.
For example, a dog is a kind of animal, but there are many breeds of dogs within the varying species of dogs.
God could bring forth many different species of dogs and breeds of dogs from a single kind of dog.
I suppose a kind would be more appropriately associated with a genus; although, the term "kind" isn't explicity defined in scripture nor is it directly associated with modern biological taxonomy.
If you step into the Christian worldview then you must allow God to be God and in doing so we trascend the bounds of naturalism. God neither requires the vehicle of evolution to bring forth many types of spiders from a single pair of spiders nor is he bound by the rules of man-made taxonomy.