The description for "Chitinous" says 1 is removed whenever defense is broken. However, if the defense is broken as a result of Ricochet damage, no Chitinous is removed.
Apply Ricochet to an ally of the Wild Flead that has Chitinous. In my case I had the Pinball battle graft, which applied Ricochet to Thug Werg at the beginning of battle during the Protection daily with Rook.
Attack the Ricochet target (Thug Werg) with a large attack.
Wild Flead's defense gets broken by Ricochet damage, but Chitinous does not decrease.