This pattern works well to imitate pale wateries, spurwings and pale coloured olives. Mostly useful in April, May, June and July. It will take trout feeding on the above mentioned flies that are emerging or are returning to the water to lay their eggs.
A good olive imitation for when olives are emerging or struggling in or just below the surface film. It’s also a great choice for prospecting for trout with spiders.
Red and black is a killer combination for most predatory fish and large brown trout are no different in that respect. I find this one works best when you strip it aggressively on the retrieve