Fear of the Great Barrier Reef

Piranha 3-D

The disaster of mad bear

shark zone/jurassic shark

Mysterious cave

Spiders in the sky are extinct.

Black toxin 2

Black calf whale

Skeeter

Exotic curses and disasters

Venice shark

Deep sea shark

Crazy python

Lion's Mouth Scare (Kill the Jedi Lion)

Kaw

Crazy sheep

Crocodile beast

A deadly insect disaster

metamorphosis/ morphman

Man-eating ant corps

Python disaster 2 looking for blood orchid

Animal powder

Rush out of the wormhole

Killer bees.

Franken fish.

Dark Invasion

Ice Spiders

Magic cave

What you are looking for is "Spider Extinction". There are two movies. I forget which one it is. See for yourself!