Seeing as how there's a new enemy, Luhal will cast entangle on it, with the radius set up so that the area of effect begins one square away from the PC closest to the 2nd spider. He'll be casting defensively so he doesn't provoke an attack of opportunity - this requires a DC 16 check, but with his Concentration at 11, I've got a good chance of making it.
The fun thing about Entangle is that you have to make a Strength DC 20 check just to be able to move at half-speed. -2 to attack, -4 to Dex(so -2 to AC), and even if you can move there's no running, no charging. Even better, even if you break free one round you have to make the same check again next round or you can't move again.
Carper will continue to attack the first spider, as will Luhal until it dies.
I suggest that everyone stand back and take out the second spider with missile weapons unless it gets to the edge of the entangled area - Luhal and Carper will take point (ie, wait at the edge of the spell) since their missile weapons suck and they have the strength spell up.
By the way, are the tiny spiders a threat?
-Albert