Not a spider

photo by Matt Ball

Photo by Carol Tornow, 9/2/11

Quite a few of the monsoon bloomers to be seen in the canyon, including the Scarlet (or Red) Spiderling (Boerhavia coccinea). The Scarlet Spiderling is in the Four-O'Clock (Nyctaginaceae) Family, as is the Trailing Four O'Clock (Allionia incarnata) below, conveniently enough.

Photo by Matt Ball

Both grow low and spread. The Trailing Four O'Clock has dime to quarter-sized flowers; the Scarlet Spiderling has clusters of tiny magenta-colored flowers.
And, if you said 'complete', you are completely right about moth and butterfly metamorphosis. Insects that spin, build, or bury and completely disassemble themselves in order to 'get their wings' undergo complete metamorphosis. (Remember: Spiders aren't insects. They often spin, but never 'get wings', so no metamorphosis for them.)