Arcane
From MHWiki
Traps utilizing arcane damage come from sources shrouded in mystery. The strength of arcane damage increases proportionally against stronger shadow and forgotten mice, making the traps especially effective in the Catacombs.
A potential new trap type. First discovered on January 29, 2009. Hunters can visit the Trapsmith and click on the "help" tab to find its description:
Little to nothing else is known as of now.