When matching the hatch, choosing a fly color is not always as simple as matching the color of the naturals. For many species of fresh water shrimp (scuds) parasite loads of infected individuals can result in their natural colors fading to a ghost-like hue. Without the advantage of camouflage these ghost scuds are more prone to predation by hungry trout.
|A typical olive scud|
|A scud infected with Acanthocephalan parasites.|
|The Blue Dun Scud|
|An infected scud showing the typical orange spot along the back where the parasites have congregated.|